Treatment of peri-implantitis using nonsurgical debridement combined with bioresorbable doxycycline nanospheres: a case report with 3-year follow-up

Treatment of peri-implant diseases focuses on reducing the bacterial load and consequent infection control. The use of local antimicrobials as an adjunct to mechanical therapy may result in a better outcome. Among antimicrobials, doxycycline stands out because of its local modulation of cytokines, microbial reduction, and clinical parameters in the treatment of periodontal diseases. The objective of this case report was to describe the combined application of mechanical debridement and bioresorbable doxycycline-loaded nanospheres for the treatment of peri-implantitis in a 71-year-old man. At the 3-year evaluation, the peri-implant tissues had improved, showing decreased probing depths, an absence of bleeding on probing, and no suppuration. This case report highlights the importance of supportive therapy, which is essential for the long-term success of peri-implantitis treatment.

Guidelines of care for the management of acne vulgaris

BACKGROUND

Acne vulgaris commonly affects adults, adolescents, and preadolescents aged 9 years or older.

OBJECTIVE

The objective of this study was to provide evidence-based recommendations for the management of acne.

METHODS

A work group conducted a systematic review and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of evidence and formulating and grading recommendations.

RESULTS

This guideline presents 18 evidence-based recommendations and 5 good practice statements. Strong recommendations are made for benzoyl peroxide, topical retinoids, topical antibiotics, and oral doxycycline. Oral isotretinoin is strongly recommended for acne that is severe, causing psychosocial burden or scarring, or failing standard oral or topical therapy. Conditional recommendations are made for topical clascoterone, salicylic acid, and azelaic acid, as well as for oral minocycline, sarecycline, combined oral contraceptive pills, and spironolactone. Combining topical therapies with multiple mechanisms of action, limiting systemic antibiotic use, combining systemic antibiotics with topical therapies, and adding intralesional corticosteroid injections for larger acne lesions are recommended as good practice statements.

LIMITATIONS

Analysis is based on the best available evidence at the time of the systematic review.

CONCLUSIONS

These guidelines provide evidence-based recommendations for the management of acne vulgaris.

Pharmacokinetic behaviour and pharmacokinetic-pharmacodynamic integration of doxycycline in rainbow trout (Oncorhynchus mykiss) after intravascular, intramuscular and oral administrations

OBJECTIVE

Doxycycline (DO) has been used in fish for a long time, but there are some factors that have not yet been clarified regarding its pharmacokinetic (PK) and pharmacodynamic (PD) properties. Therefore, the aim of this study was to investigate the PK and PK/PD targets of DO after 20 mg/kg intravascular (IV), intramuscular (IM) and oral (OR) gavage administration in rainbow trout (Oncorhynchus mykiss).

METHODS

Plasma samples were collected at specific time points and subsequently analysed by HPLC-ultraviolet. The PK/PD indices were calculated based on the MIC90 (Aeromonas hydrophila and Aeromonas sobria) values obtained for the respective bacteria and the PK parameters obtained for DO following both IM and OR administration.

RESULTS

After IV administration, the elimination half-life (t1/2 ʎz), area under the concentration vs. time curve (AUC), apparent volume of distribution at steady-state and total body clearance of DO were 34.81 h, 723.82 h µg/mL, 1.24 L/kg and 0.03 L/kg/h, respectively. The t1/2λz of the DO was found to be 37.39 and 39.78 h after IM, and OR administration, respectively. The bioavailability was calculated 57.02% and 32.29%, respectively, after IM and OR administration. The MIC90 of DO against A. hydrophila and A. sobria was 4 µg/mL. The PK/PD integration showed that DO (20 mg/kg dose) for A. hydrophila and A. sobria with MIC90 ≤4 µg/mL achieved target AUC/MIC value after IM administration.

CONCLUSIONS

These results suggest that when rainbow trout was treated with 20 mg/kg IV and IM administered DO, therapeutically effective concentrations were reached in the control of infections caused by A. hydrophila and A. sobria.

Trends in Chlamydia trachomatis Treatment Prescribing Practices in King County, Washington, 2010-2018

BACKGROUND

In 2021, national Chlamydia trachomatis (CT) treatment guidelines changed from recommending either azithromycin (1 g; single dose) or doxycycline (100 mg twice daily for 7 days) to recommending only doxycycline as first-line treatment. The distribution and trends in CT prescribing practices before the guidelines change is largely unknown.

METHODS

We conducted a trends analysis using Washington STD surveillance data. We included all female cases of urogenital CT 15 years or older who resided in King County and were diagnosed between 2010 and 2018. Surveillance data included information on demographics, sexual history, clinical features, diagnosing facility (eg, emergency department, family planning), and treatment regimen. We conducted descriptive analyses to examine trends in prescribing practices over time and by facility type. We used Poisson regression to examine the association between CT case characteristics and receipt of receipt of azithromycin.

RESULTS

There were 36,830 cases of female urogenital CT during the study period. The percent of cases receiving azithromycin increased significantly from 86% in 2010 to 94% in 2018; the percent receiving doxycycline decreased from 13% to 5%. Five of the 8 facility types prescribed azithromycin to >95% of CT cases by 2018. Cases who were younger or cases of color were more likely to receive azithromycin (versus doxycycline) compared with older and White cases, respectively.

CONCLUSIONS

A substantial shift in CT prescribing practices will be needed to adhere to new CT treatment guidelines. Our findings highlight the need for targeted provider education and training to encourage the transition to doxycycline use.

Doxycycline cotherapy with albendazole relieves neural function damage in C57BL/6 and BALB/c mice infected with Angiostrongylus cantonensis

BACKGROUND

We investigated the effects of combination therapy albendazole and doxycycline in Angiostrongylus cantonensis-infected mice during early and late treatment.

MATERIALS AND METHODS

C57BL/6 and BALB/c mice were divided into five groups: (i) uninfected, (ii) infected with A. cantonensis, (iii) infected + 10 mg/kg albendazole, (iv) infected + 25mg/kg doxycycline, and (v) infected + 10 mg/kg albendazole + 25 mg/kg doxycycline. We administered drugs in both early treatments started at 7-day post infections (dpi) and late treatments (14 dpi) to A. cantonensis-infected C57BL/6 and BALB/c mice. To assess the impact of these treatments, we employed the Morris water maze test to evaluate spatial learning and memory abilities, and the rotarod test to measure motor coordination and balance in C57BL/6 mice. Additionally, we monitored the expression of the cytokine IL-33 and GFAP in the brain of these mice using western blot analysis.

RESULTS

In this study, A. cantonensis infection was observed to cause extensive cerebral angiostrongyliasis in C57BL/6 mice. This condition significantly affected their spatial learning and memory abilities, as assessed by the Morris water maze test, as well as their motor coordination, which was evaluated using the rotarod test. Early treatment with albendazole led to favorable recovery outcomes. Both C57BL/6 and BALB/c mice express IL-33 and GFAP after co-therapy. The differences of levels and patterns of IL-33 and GFAP expression in mice may be influenced by the balance between pro-inflammatory and anti-inflammatory signals within the immune system.

CONCLUSIONS

Combination therapy with anthelmintics and antibiotics in the early stage of A. cantonensis infection, in C57BL/6 and BALB/c mice resulted in the death of parasites in the brain and reduced the subsequent neural function damage and slowed brain damage and neurobehavior impairment. This study suggests a more effective and novel treatment, and drug delivery method for brain lesions that can decrease the neurological damage of angiostrongyliasis patients.

One Incremental Stride for Doxycycline, One Substantial Advancement for Thyroid Eye Disease

The aim of this study is to assess the effectiveness of a 12-week doxycycline treatment for thyroid eye disease (TED), an autoimmune condition associated with thyroid dysfunction. In this randomized controlled clinical trial, 82 patients were randomly assigned at a 1:1 ratio to receive doxycycline (50 mg) or to undergo no treatment. Various metrics, including margin reflex distance (MRD1 and MRD2), eyelid aperture, levator muscle function, lagophthalmos, proptosis, ocular motility, diplopia, and Graves' ophthalmopathy-specific quality-of-life (GO-QOL) scale scoring were assessed. Exclusion criteria were uncontrolled systemic diseases, tetracycline allergies, pregnancy, lactation, or age below 18. The mean age was 51.6 years (SD), 87.8% of participants were female, and all were Caucasians. By week 12, the doxycycline group exhibited a significant improvement rate based on MRD2 (from 4 to 15 participants with physiological findings), clinical activity score (from 7 to 35 participants with non-active disease), and GO-QOL (from 51.22% to 70.73% of participants with a good life quality). Doxycycline showcased anti-inflammatory and immunomodulatory effects in treating TED, suggesting its potential efficacy for TED and other orbit inflammatory conditions. However, these results warrant further validation through future research involving extended follow-up periods and larger cohorts.

Extended blood stage sensitivity profiles of Plasmodium cynomolgi to doxycycline and tafenoquine, as a model for Plasmodium vivax

Testing Plasmodium vivax antimicrobial sensitivity is limited to ex vivo schizont maturation assays, which preclude determining the IC50s of delayed action antimalarials such as doxycycline. Using Plasmodium cynomolgi as a model for P. vivax, we determined the physiologically significant delayed death effect induced by doxycycline [IC50(96 h), 1,401 ± 607 nM]. As expected, IC50(96 h) to chloroquine (20.4 nM), piperaquine (12.6 µM), and tafenoquine (1,424 nM) were not affected by extended exposure.

Novel Ti surface coated with PVA hydrogel and chitosan nanoparticles with antibacterial drug release: An experimental in vitro study

OBJECTIVES

The aims of this study were to design a novel titanium surface coated with a PVA hydrogel matrix and chitosan-based nanoparticles and to investigate the antibiotic release and its ability to inhibit microbial activity.

METHODS

Two drug delivery systems were developed and mixed. Chitosan-based nanoparticles (NP) and a polyvinyl alcohol film (PVA). The size, ζ-potential, stability, adhesive properties, and encapsulation profile of NP, as well as the release kinetics of drug delivery systems and their antimicrobial ability of PVA and PVANP films, were studied on Ti surfaces. The systems were loaded with doxycycline, vancomycin, and doxepin hydrochloride.

RESULTS

Nanoparticles presented a ζ-potential greater than 30 mV for 45 days and the efficiency drug encapsulation was 26.88% ± 1.51% for doxycycline, 16.09% ± 10.24% for vancomycin and 17.57% ± 11.08% for doxepin. In addition, PVA films were loaded with 125 μg/mL of doxycycline, 125 μg/mL of vancomycin, and 100 μg/mL of doxepin. PVANP-doxycycline achieved the antibacterial effect at 4 h while PVA-doxycycline maintained its effect at 24 h.

The addition of doxycycline to fluoroquinolones for bacterial prophylaxis in autologous stem cell transplantation for multiple myeloma

BACKGROUND

Bacterial prophylaxis with a fluoroquinolone (FQ) during autologous stem cell transplant (ASCT) is common, although not standardized among transplant centers. The addition of doxycycline (doxy) to FQ prophylaxis was previously linked to reduced neutropenic fever and bacteremia in multiple myeloma (MM) patients undergoing ASCT although several confounders were present. We compared the incidence of neutropenic fever and bacteremia between MM patients variably receiving prophylaxis with FQ alone and FQ-doxy during ASCT.

METHODS

Systematic retrospective chart review of MM patients who underwent ASCT between January 2016 and December 2021. The primary objective was to determine the effect of bacterial prophylaxis on neutropenic fever and bacteremia within 30 days of ASCT. Multivariable logistic regression for neutropenic fever and univariate logistic regression for bacteremia accounted for differences in subject characteristics between groups.

RESULTS

Among 341 subjects, 121 received FQ and 220 received FQ-doxy for prophylaxis. Neutropenic fever developed in 67 (55.4%) and 87 (39.5%) subjects in the FQ and FQ-doxy groups, respectively (p = .005). Bacteremia was infrequent, with 5 (4.1%) and 5 (2.3%) cases developing in the FQ and FQ-doxy groups, respectively (p = .337). Among Gram-negative bacteremia events, 7/7 Escherichia coli strains were FQ-resistant, and 5/7 were ceftriaxone-resistant.

CONCLUSION

The FQ-doxy prophylaxis group had fewer cases of neutropenic fever than the FQ group, however, there was no significant difference in bacteremia. High rates of antibiotic resistance were observed. An updated randomized controlled trial investigating appropriate prophylaxis for ASCT in the context of current oncology standards and changing antimicrobial resistance rates is warranted.

Doxycycline as Postsexual Exposure Prophylaxis: Use, Acceptability, and Associated Sexual Health Behaviors Among a Multi-Site Sample of Clinical Trial Participants

Doxycycline postexposure prophylaxis (doxy-PEP) reduces sexually transmitted infections (STIs) in men who have sex with men (MSM) and transgender women (TGW). In a clinical trial of doxy-PEP, we sought to assess acceptability, impact, and meaning of doxy-PEP use among MSM/TGW. We conducted semistructured, in-depth 1:1 interviews with MSM and TGW enrolled in the intervention arm of the Doxy-PEP study. We queried motivations for and meaning of use, attitudes, beliefs, adherence, effect on sexual behaviors, and partner, community, and structural factors related to use. We coded interview transcripts into content areas, followed by thematic analysis. We interviewed 44 participants (median age 38), 2% were TGW, 17% Black, 61% White, 30% Hispanic, and 45% persons with HIV. We identified three overarching themes. First, participants found doxy-PEP acceptable, and believed it was effective based on their history of STIs, easy to adhere to, and acceptable to sex partners. Second, doxy-PEP benefited their quality of life and mental health, offering "peace of mind" by reducing their anxiety about acquisition or unwitting transmission of STIs. Participants reported feeling more "in control" of preventing STIs, and positive about supporting their personal, partner, and community health. Third, impact on sexual behavior was variable, with most reporting no change or a brief initial change. Participants in a multi-site clinical trial of doxycycline for STI prevention perceived it to be efficacious, and that it provided quality-of-life benefits, including reduced anxiety and sense of control over sexual health. Doxy-PEP had limited impact on sexual behavior. Clinicaltrials.gov: NCT03980223.

Low Rate of Postoperative Pterygium Recurrence in Patients under Treatment with Low-Dose Oral Doxycycline for Chronic Blepharitis: A First Report

PURPOSE

Low doses of systemic doxycycline (LD-SD) inhibit angiogenesis and the expression of matrix metalloproteases, which are determinants of pterygium progression. This study aimed to compare the recurrence rate and visual outcome of pterygium excision in patients undergoing chronic treatment with LD-SD for chronic refractory blepharitis and LD-SD-naive patients.

METHODS

A retrospective analysis of patients that underwent surgical excision and conjunctival graft apposition was conducted. Patients were divided in a TETRA group (under LD-SD treatment at the moment of surgery) and a control group. The main outcome was the rate of recurrence at 1 year postoperatively. Secondary outcomes were the comparisons of surface regularity, visual quality, and dry-eye symptoms at 6-week, 6-month, and 1-year follow-up in the two groups.

RESULTS

The TETRA group showed a significantly lower rate of 1-year recurrence both in primary (p = 0.034) and recurrent (p < 0.001) pterygia. The best corrected visual acuity (BCVA), astigmatic error, corneal total root mean square (RMS), and ocular surface disease index (OSDI) significantly reduced during the follow-up in both groups. The surface asymmetry index and high-order aberrations (HOAs) significantly reduced only in the TETRA group. The final BCVA was significantly higher, while the OSDI score and total RMS and HOAs were significantly lower in the TETRA group compared to the control.

CONCLUSIONS

Patients under treatment with LD-SD showed a lower rate of recurrence at 1-year follow-up compared to controls. These patients also experienced higher BCVA and surface regularity and less dry-eye symptoms.

Effects of Doxycycline-Loaded NO-Releasing Nanomatrix Gel on Delayed Replanted of Rat Molar

BACKGROUND/AIM

Tooth avulsion and delayed replantation may cause inflammatory responses and root resorption of the tooth. The aim of this study is to investigate the effect of a doxycycline-loaded nitric oxide-releasing nanomatrix (DN) gel on the delayed replantation of avulsed rat teeth, with a focus on assessing the gel's potential to promote regeneration and inhibit complications associated with the replantation process.

MATERIALS AND METHODS

Twenty-four right maxillary first molars from male Sprague-Dawley rats were atraumatically extracted using sterile extraction forceps. The molars were dried for 1 h at room temperature (approximately 23 °C) and divided into four groups according to the root conditioning methods after extra-alveolar 60-min drying: Group 1, no root conditioning treatment prior to replantation; Group 2, soaking in 2% NaF solution for 5 min before replantation; Group 3, 5-min soaking in NO gel and injection of the gel into the alveolar socket; Group 4, 5-min soaking in DN gel and injection of the gel into the alveolar socket before replantation. The animals were euthanized four weeks after the operation and the specimens were evaluated histologically.

RESULTS

The use of NO gel alone showed better anti-inflammatory and periodontal effects than the control group, but it did not show a significant effect compared to the group using NaF. When using NO gel loaded with doxycycline, it showed a significant anti-inflammatory effect compared to the control group and showed a similar inhibitory effect to the group using NaF.

CONCLUSIONS

Within the limits of this study, in delayed replantation situations, the control of inflammatory resorption and replacement resorption is an important factor for achieving a better prognosis of replanted teeth. Root surface treatment with DN gel decreased root resorption after delayed replantation.

Real-time measurements of ATP dynamics via ATeams in Plasmodium falciparum reveal drug-class-specific response patterns

Malaria tropica, caused by the parasite Plasmodium falciparum (P. falciparum), remains one of the greatest public health burdens for humankind. Due to its pivotal role in parasite survival, the energy metabolism of P. falciparum is an interesting target for drug design. To this end, analysis of the central metabolite adenosine triphosphate (ATP) is of great interest. So far, only cell-disruptive or intensiometric ATP assays have been available in this system, with various drawbacks for mechanistic interpretation and partly inconsistent results. To address this, we have established fluorescent probes, based on Förster resonance energy transfer (FRET) and known as ATeam, for use in blood-stage parasites. ATeams are capable of measuring MgATP2- levels in a ratiometric manner, thereby facilitating in cellulo measurements of ATP dynamics in real-time using fluorescence microscopy and plate reader detection and overcoming many of the obstacles of established ATP analysis methods. Additionally, we established a superfolder variant of the ratiometric pH sensor pHluorin (sfpHluorin) in P. falciparum to monitor pH homeostasis and control for pH fluctuations, which may affect ATeam measurements. We characterized recombinant ATeam and sfpHluorin protein in vitro and stably integrated the sensors into the genome of the P. falciparum NF54attB cell line. Using these new tools, we found distinct sensor response patterns caused by several different drug classes. Arylamino alcohols increased and redox cyclers decreased ATP; doxycycline caused first-cycle cytosol alkalization; and 4-aminoquinolines caused aberrant proteolysis. Our results open up a completely new perspective on drugs' mode of action, with possible implications for target identification and drug development.

Antibiotics for treatment of leptospirosis

BACKGROUND

Leptospirosis is a disease transmitted from animals to humans through water, soil, or food contaminated with the urine of infected animals, caused by pathogenic Leptospira species. Antibiotics are commonly prescribed for the management of leptospirosis. Despite the widespread use of antibiotic treatment for leptospirosis, there seems to be insufficient evidence to determine its effectiveness or to recommend antibiotic use as a standard practice. This updated systematic review evaluated the available evidence regarding the use of antibiotics in treating leptospirosis, building upon a previously published Cochrane review.

OBJECTIVES

To evaluate the benefits and harms of antibiotics versus placebo, no intervention, or another antibiotic for the treatment of people with leptospirosis.

SEARCH METHODS

We identified randomised clinical trials following standard Cochrane procedures. The date of the last search was 27 March 2023.

SELECTION CRITERIA

We searched for randomised clinical trials of various designs that examined the use of antibiotics for treating leptospirosis. We did not impose any restrictions based on the age, sex, occupation, or comorbidities of the participants involved in the trials. Our search encompassed trials that evaluated antibiotics, regardless of the method of administration, dosage, and schedule, and compared them with placebo or no intervention, or compared different antibiotics. We included trials regardless of the outcomes reported.

DATA COLLECTION AND ANALYSIS

During the preparation of this review, we adhered to the Cochrane methodology and used Review Manager. The primary outcomes were all-cause mortality and serious adverse events (nosocomial infection). Our secondary outcomes were quality of life, proportion of people with adverse events considered non-serious, and days of hospitalisation. To assess the risk of bias of the included trials, we used the RoB 2 tool, and for evaluating the certainty of evidence we used GRADEpro GDT software. We presented dichotomous outcomes as risk ratios (RR) and continuous outcomes as mean differences (MD), both accompanied by their corresponding 95% confidence intervals (CI). We used the random-effects model for all our main analyses and the fixed-effect model for sensitivity analyses. For our primary outcome analyses, we included trial data from the longest follow-up period.

MAIN RESULTS

We identified nine randomised clinical trials comprising 1019 participants. Seven trials compared two intervention groups and two trials compared three intervention groups. Amongst the trials comparing antibiotics versus placebos, four trials assessed penicillin and one trial assessed doxycycline. In the trials comparing different antibiotics, one trial evaluated doxycycline versus azithromycin, one trial assessed penicillin versus doxycycline versus cefotaxime, and one trial evaluated ceftriaxone versus penicillin. One trial assessed penicillin with chloramphenicol and no intervention. Apart from two trials that recruited military personnel stationed in endemic areas or military personnel returning from training courses in endemic areas, the remaining trials recruited people from the general population presenting to the hospital with fever in an endemic area. The participants' ages in the included trials was 13 to 92 years. The treatment duration was seven days for penicillin, doxycycline, and cephalosporins; five days for chloramphenicol; and three days for azithromycin. The follow-up durations varied across trials, with three trials not specifying their follow-up periods. Three trials were excluded from quantitative synthesis; one reported zero events for a prespecified outcome, and two did not provide data for any prespecified outcomes. Antibiotics versus placebo or no intervention The evidence is very uncertain about the effect of penicillin versus placebo on all-cause mortality (RR 1.57, 95% CI 0.65 to 3.79; I2 = 8%; 3 trials, 367 participants; very low-certainty evidence). The evidence is very uncertain about the effect of penicillin or chloramphenicol versus placebo on adverse events considered non-serious (RR 1.05, 95% CI 0.35 to 3.17; I2 = 0%; 2 trials, 162 participants; very low-certainty evidence). None of the included trials assessed serious adverse events. Antibiotics versus another antibiotic The evidence is very uncertain about the effect of penicillin versus cephalosporin on all-cause mortality (RR 1.38, 95% CI 0.47 to 4.04; I2 = 0%; 2 trials, 348 participants; very low-certainty evidence), or versus doxycycline (RR 0.93, 95% CI 0.13 to 6.46; 1 trial, 168 participants; very low-certainty evidence). The evidence is very uncertain about the effect of cefotaxime versus doxycycline on all-cause mortality (RR 0.18, 95% CI 0.01 to 3.78; 1 trial, 169 participants; very low-certainty evidence). The evidence is very uncertain about the effect of penicillin versus doxycycline on serious adverse events (nosocomial infection) (RR 0.62, 95% CI 0.11 to 3.62; 1 trial, 168 participants; very low-certainty evidence) or versus cefotaxime (RR 1.01, 95% CI 0.15 to 7.02; 1 trial, 175 participants; very low-certainty evidence). The evidence is very uncertain about the effect of doxycycline versus cefotaxime on serious adverse events (nosocomial infection) (RR 1.01, 95% CI 0.15 to 7.02; 1 trial, 175 participants; very low-certainty evidence). The evidence is very uncertain about the effect of penicillin versus cefotaxime (RR 3.03, 95% CI 0.13 to 73.47; 1 trial, 175 participants; very low-certainty evidence), versus doxycycline (RR 2.80, 95% CI 0.12 to 67.66; 1 trial, 175 participants; very low-certainty evidence), or versus chloramphenicol on adverse events considered non-serious (RR 0.74, 95% CI 0.15 to 3.67; 1 trial, 52 participants; very low-certainty evidence). Funding Six of the nine trials included statements disclosing their funding/supporting sources and three trials did not mention funding source. Four of the six trials mentioning sources received funds from public or governmental sources or from international charitable sources, and the remaining two, in addition to public or governmental sources, received support in the form of trial drug supply directly from pharmaceutical companies.

AUTHORS' CONCLUSIONS

As the certainty of evidence is very low, we do not know if antibiotics provide little to no effect on all-cause mortality, serious adverse events, or adverse events considered non-serious. There is a lack of definitive rigorous data from randomised trials to support the use of antibiotics for treating leptospirosis infection, and the absence of trials reporting data on clinically relevant outcomes further adds to this limitation.

Antibiotic prophylaxis for leptospirosis

BACKGROUND

Leptospirosis is a global zoonotic and waterborne disease caused by pathogenic Leptospira species. Antibiotics are used as a strategy for prevention of leptospirosis, in particular in travellers and high-risk groups. However, the clinical benefits are unknown, especially when considering possible treatment-associated adverse effects. This review assesses the use of antibiotic prophylaxis in leptospirosis and is an update of a previously published review in the Cochrane Library (2009, Issue 3).

OBJECTIVES

To evaluate the benefits and harms of antibiotic prophylaxis for human leptospirosis.

SEARCH METHODS

We identified randomised clinical trials through electronic searches of the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and other resources. We searched online clinical trial registries to identify unpublished or ongoing trials. We checked reference lists of the retrieved studies for further trials. The last date of search was 17 April 2023.

SELECTION CRITERIA

We included ⁠⁠randomised clinical trials of any trial design, assessing antibiotics for prevention of leptospirosis, and with no restrictions on age, sex, occupation, or comorbidity of trial participants. We looked for trials assessing antibiotics irrespective of route of administration, dosage, and schedule versus placebo or no intervention. We also included trials assessing antibiotics versus other antibiotics using these criteria, or the same antibiotic but with another dose or schedule.

DATA COLLECTION AND ANALYSIS

We followed Cochrane methodology. The primary outcomes were all-cause mortality, laboratory-confirmed leptospirosis regardless of the presence of an identified clinical syndrome (inclusive of asymptomatic cases), clinical diagnosis of leptospirosis regardless of the presence of laboratory confirmation, clinical diagnosis of leptospirosis confirmed by laboratory diagnosis (exclusive of asymptomatic cases), and serious adverse events. The secondary outcomes were quality of life and the proportion of people with non-serious adverse events. We assessed the risk of bias of the included trials using the RoB 2 tool and the certainty of evidence using GRADE. We presented dichotomous outcomes as risk ratios (RR) and continuous outcomes as mean difference (MD), with their 95% confidence intervals (CI). We used a random-effects model for our main analyses and the fixed-effect model for sensitivity analyses. Our primary outcome analyses included trial data at the longest follow-up.

MAIN RESULTS

We identified five randomised clinical trials comprising 2593 participants that compared antibiotics (doxycycline, azithromycin, or penicillin) with placebo, or one antibiotic compared with another. Four trials assessed doxycycline with different durations, one trial assessed azithromycin, and one trial assessed penicillin. One trial had three intervention groups: doxycycline, azithromycin, and placebo. Three trials assessed pre-exposure prophylaxis, one trial assessed postexposure prophylaxis, and one did not report this clearly. Four trials recruited residents in endemic areas, and one trial recruited soldiers who experienced limited time exposure. The participants' ages in the included trials were 10 to 80 years. Follow-up ranged from one to three months. Antibiotics versus placebo Doxycycline compared with placebo may result in little to no difference in all-cause mortality (RR 0.15, 95% CI 0.01 to 2.83; 1 trial, 782 participants; low-certainty evidence). Prophylactic antibiotics may have little to no effect on laboratory-confirmed leptospirosis, but the evidence is very uncertain (RR 0.56, 95% CI 0.25 to 1.26; 5 trials, 2593 participants; very low-certainty evidence). Antibiotics may result in little to no difference in the clinical diagnosis of leptospirosis regardless of laboratory confirmation (RR 0.76, 95% CI 0.53 to 1.08; 4 trials, 1653 participants; low-certainty evidence) and the clinical diagnosis of leptospirosis with laboratory confirmation (RR 0.57, 95% CI 0.26 to 1.26; 4 trials, 1653 participants; low-certainty evidence). Antibiotics compared with placebo may increase non-serious adverse events, but the evidence is very uncertain (RR 10.13, 95% CI 2.40 to 42.71; 3 trials, 1909 participants; very low-certainty evidence). One antibiotic versus another antibiotic One trial assessed doxycycline versus azithromycin but did not report mortality. Compared to azithromycin, doxycycline may have little to no effect on laboratory-confirmed leptospirosis regardless of the presence of an identified clinical syndrome (RR 1.49, 95% CI 0.51 to 4.32; 1 trial, 137 participants), on the clinical diagnosis of leptospirosis regardless of the presence of laboratory confirmation (RR 4.18, 95% CI 0.94 to 18.66; 1 trial, 137 participants), on the clinical diagnosis of leptospirosis confirmed by laboratory diagnosis (RR 4.18, 95% CI 0.94 to 18.66; 1 trial, 137 participants), and on non-serious adverse events (RR 1.12, 95% CI 0.36 to 3.48; 1 trial, 137 participants), but the evidence is very uncertain. The certainty of evidence for all the outcomes was very low. None of the five included trials reported serious adverse events or assessed quality of life. One study is awaiting classification. Funding Four of the five trials included statements disclosing their funding/supporting sources, and the remaining trial did not include this. Three of the four trials that disclosed their supporting sources received the supply of trial drugs directly from the same pharmaceutical company, and the remaining trial received financial support from a governmental source.

AUTHORS' CONCLUSIONS

We do not know if antibiotics versus placebo or another antibiotic has little or have no effect on all-cause mortality or leptospirosis infection because the certainty of evidence is low or very low. We do not know if antibiotics versus placebo may increase the overall risk of non-serious adverse events because of very low-certainty evidence. We lack definitive rigorous data from randomised trials to support the use of antibiotics for the prophylaxis of leptospirosis infection. We lack trials reporting data on clinically relevant outcomes.

Clinical and Microbiological Evaluation of Diode Laser and Systemic Doxycycline as an Additive to Scaling and Root Planing for Stage II and Stage III Periodontitis Patients

AIM

To assess and contrast the effectiveness of systemic doxycycline and diode laser as supplements to scaling and root planing (SRP) in terms of clinical and microbiological parameters.

MATERIALS AND METHODS

A total of 33 patients diagnosed with periodontitis stages II and III were included and randomized into group A (SRP + diode laser), group B (SRP + doxycycline), and group C (SRP alone). Selected sites were assessed for clinical and microbial parameters-plaque index (PI), gingival index (GI), pocket probing depth (PPD), relative attachment level (RAL), and colony-forming units (CFUs). Every clinical parameter was noted at baseline and after three months. The arithmetic mean, followed by the standard deviation, was calculated for the required assessment intervals. Analysis of variance (ANOVA) was used to compare all parameters between groups, and if the results of the ANOVA test were significant, post hoc analysis was performed. For intragroup comparison, student t-tests were performed.

RESULTS

The clinical parameters significantly improved within three months for all groups. In terms of relative attachment level, a statistically significant difference (P < 0.001) was obtained at the three-month interval compared to the baseline value, with the most statistically significant difference seen in group A (3.36±0.50 to 0.64±0.50), followed by group B (3.18±0.40 to 2.18±0.40). The mean pocket probing depth observed at three months, compared to the baseline value, showed a statistically significant difference (P < 0.001) in group A (5.91±0.70 to 2.18±0.40) compared to group B (6.18±0.75 to 4.36±0.50), followed by group C (5.82±0.75 to 5.27±0.64).

CONCLUSION

The use of diode laser-assisted pocket disinfection and systemic doxycycline, in addition to scaling and root planing, has proven to be efficient for treating periodontal pockets.

Comparative Evaluation of Push-Out Bond Strength of Conventional Mineral Trioxide Aggregate, Biodentine, a Modified Mineral Trioxide Aggregate, and Two Novel Antibacterial-Enhanced Mineral Trioxide Aggregates

Background The challenges associated with incorporating antimicrobial agents, such as the potential diminishment of the cement's physical properties, highlight the need for comprehensive evaluations. Balancing antimicrobial efficacy with the maintenance of structural integrity is a crucial aspect of material development. The acknowledgment of cytotoxic properties associated with tricalcium aluminate, a major constituent in conventional mineral trioxide aggregate (MTA), is critical in terms of long-term evaluation of treatment procedures. The primary focus of the push-out test is to evaluate the resistance of the tested material to dislodgement. Greater push-out strength implies stronger adhesion between the tested material and the tooth surface. Aim This study aims to evaluate the push-out bond strength of two antibacterial-enhanced MTAs with conventional MTA and Biodentine. Material and methods A total of five materials were tested: a) modified MTA, b) doxycycline-enhanced MTA, c) metronidazole-enhanced MTA, d) conventional MTA, and e) Biodentine. All the materials were mixed based on a predetermined powder:liquid ratio and then carried using a plastic instrument to the desired experimental design. Single-rooted permanent teeth, preferably incisors, were used in the present study. Teeth were embedded vertically in a rubber mold, and sectioning of the tooth was performed. A single operator instrumented the canal space in each slice using Gates-Glidden burs, and the mixed cements were placed in the respective groups and stored for 72 hours. A push-out test was carried out using a universal testing machine. Following the bond failure, the slices were examined under a stereomicroscope to determine the nature of the bond failure. The collected data was subjected to a one-way analysis of variance test, post hoc test, and chi-square test for statistical analysis. Results The mean push-out bond strength was found to be the highest for Biodentine (43.25 ± 0.62 megapascals (MPa)), followed by doxycycline- and metronidazole-enhanced MTAs (39.54 ± 0.65 MPa and 39.29 ± 0.16 MPa, respectively), modified MTA formulation (37.75 ± 0.73 MPa), and the lowest for conventional MTA (25.93 ± 0.7 MPa). Conventional MTA samples had an adhesive failure (89.4%), while Biodentine samples had a cohesive failure (80.3%). Mixed failures were noticed with the samples containing modified MTA formulation (71.3%), doxycycline-enhanced MTA (76.6%), and metronidazole-enhanced MTA (78.0%). Conclusion Despite not surpassing Biodentine in bond strength, antibacterial-enhanced MTAs are considered potential alternatives to conventional MTA in day-to-day clinical practice.

Acute Pyelonephritis by Scrub Typhus: A Rare Condition

Scrub typhus is prevalent in tropical countries and can have a varied spectrum of presentations from pneumonia, gastroenteritis, lymphadenitis, meningitis, encephalitis, and acute kidney injury to multi-organ dysfunction syndrome. Urinary tract infections like cystitis and pyelonephritis are rarely reported. Here we present an atypical presentation of a 53-year-old female with diabetes mellitus who came to the outpatient department with complaints of high-grade fever, burning micturition, and left flank pain for three days and was initially treated outpatient basis with oral antibiotics. However, her deteriorating condition landed her in an emergency in a state of septic shock. She was initially treated with broad-spectrum conventional antibiotics with other supportive medications. Even after confirmation of the diagnosis of left acute pyelonephritis with septic shock, with appropriate antibiotics, her condition was deteriorating. A sterile urine culture raised suspicion of atypical organisms causing the infection. Proper analysis of her history and readily available investigations of IgM against scrub typhus antigen led to a diagnosis of scrub typhus-related left acute pyelonephritis with septic shock. She was treated adequately with an injection of doxycycline, followed by oral tablets of the same, after which she showed drastic improvement in her symptoms, and then she was discharged. Thus, atypical organisms causing urinary tract infections should be kept always in mind, which can be treated easily and if untreated, can lead to life-threatening consequences.

Modelling of doxycycline-based prevention of bacterial sexually transmitted infections in comparison to condom-based and test-based prevention

Background

Doxycycline-based prevention of bacterial sexually transmitted infections (STIs) has been assessed in various studies and has been recommended by the European AIDS Clinical Society to be proposed to persons with repeated STIs on a case-by-case basis. However, while good preventive effects could be shown for Chlamydia trachomatis and Treponema pallidum in Europe, no reliable prevention against doxycycline resistance-affected bacterial causes of STIs like Neisseria gonorrhoeae and Mycoplasma genitalium was confirmed.

Methods

In a modelling-approach, we assessed potential beneficial effects even against the latter microorganisms in case of optimized adherence with doxycycline prevention. These effects were modelled for Germany in comparison to traditional prevention schemes like condom-based STI-prevention and testing-as-prevention.

Results

With estimated risk reduction in the ranges of 86% for N. gonorrhoeae and of 82% for Mycoplasma genitalium, expectable preventive efficacy similar to alternative preventive approaches could be calculated in case of optimized adherence with doxycycline prevention. In case of repeated risk exposure, the preventive potential of condom-based prevention was decreased compared to both optimized doxycycline prevention and testing-as-prevention.

Conclusions

As suggested by the applied modelling, the preventive effect of optimized doxycycline prevention against bacterial STIs is in a similar range, like other common prevention strategies.

ROS-Responsive Poly(α-l-lysine)-Based Nanoparticles Loaded with Doxycycline Combat Oxidative Stress and Bacterial Infection

Bacterial pneumonia is one of the major threats in clinical practice, and the reactive oxygen species (ROS) generated at the infection site can exacerbate the damage. Currently, conventional antibiotic therapies have low utilization, and their excessive use can result in substantial toxicity. Nanocarrier systems provide an ideal approach for treating bacterial infection by facilitating more efficient utilization of antibiotics. In this study, the ROS-responsive amphiphilic nanoparticles (NPs) are developed and used to encapsulate the antibiotic doxycycline (DOXY) to achieve antibacterial and antioxidant functionalities. The NPs are prepared from poly(α-l-lysine) (α-PLL) and phenylboronic acid pinacol ester simultaneously conjugated carbonyldiimidazole (abbreviated as CDIPB). The phenylboronic acid ester groups on CDIPB could react with excessive ROS to suppress oxidative damage at the infection site. The ROS-responsive degradation of CDIPB also facilitates the rapid release of internal DOXY, effectively killing the accumulated bacteria. Additionally, in vitro cell experiments demonstrate the good biocompatibility of the NPs. These results suggest that the ROS-responsive amphiphilic nanoparticles can serve as a novel nanoplatform for the treatment of bacterial pneumonia.

Efficacy of Spironolactone Compared with Doxycycline in Moderate Acne in Adult Females: Results of the Multicentre, Controlled, Randomized, Double-blind Prospective and Parallel Female Acne Spironolactone vs doxyCycline Efficacy (FASCE) Study

Acne in adult females is triggered mainly by hormones. Doxycycline is a reference treatment in acne. Spironolactone targets the androgen receptor of sebaceous glands and is prescribed off-label for female adult acne. This multicentre, controlled, randomized, double-blind prospective and parallel study assessed the efficacy of spironolactone compared with doxycycline in adult female acne. A total of 133 women with moderate acne were randomized to receive treatment with: (i) doxycycline and benzoyl peroxide for 3 months followed by a 3-month treatment with its placebo and benzoyl peroxide, or (ii) spironolactone and benzoyl peroxide for 6 months. Successfully treated patients continued with benzoyl peroxide or spironolactone alone for a further 6 months. Primary endpoints were treatment success at month 4 and month 6 with the AFAST score. At all visits, the ECLA score, lesion counts, local and systemic safety and quality of life were assessed. Spironolactone performed better at month 4 and showed a statistically significant better treatment success after 6 months than doxycycline (p = 0.007). Spironolactone was 1.37-times and 2.87-times more successful compared with doxycycline at respective time-points. AFAST and ECLA scores, as well as lesion counts always improved more with spironolactone. Patients' quality of life was better with spironolactone at month 4 and month 6. Spironolactone was very well tolerated. This is the first study to show that, in female adults with moderate acne, treatment with spironolactone is significantly more successful than doxycycline and very well tolerated.

Filling in the Gaps: Updates on Doxycycline Prophylaxis for Bacterial Sexually Transmitted Infections

Over the past two decades, cases of sexually transmitted infections (STIs) due to syphilis, gonorrhea, and chlamydia have been rising in the United States, disproportionately among gay, bisexual, and other men who have sex with men (MSM), as well as racial and ethnic minorities of all genders. In this review, we address updates about the evidence on doxycycline post-exposure prophylaxis (doxy-PEP) for prevention of bacterial STIs, including efficacy, safety, antimicrobial resistance (AMR), acceptability, modeling population impact, and evolving guidelines for use. Equitable implementation of doxy-PEP will require evaluation of who is offered and initiates it, understanding patterns of use and longer-term STI incidence and AMR, provider training, and tailored community education.

LipiFlow for the treatment of dry eye disease

BACKGROUND

Meibomian gland dysfunction (MGD) is the most common underlying cause of dry eye disease (DED). MGD leads to pathological alteration of the composition or quantity of meibum, or both, which subsequently results in tear evaporation and the typical signs and symptoms associated with DED. The LipiFlow Thermal Pulsation System (LipiFlow) is a medical device used to treat MGD in office; however, it is unclear if LipiFlow can outperform other DED treatments.

OBJECTIVES

To evaluate the effectiveness of LipiFlow for treating DED signs and symptoms and the safety of LipiFlow compared with sham or other available treatments for MGD in adults.

SEARCH METHODS

The Cochrane Eyes and Vision Information Specialist searched the electronic databases for randomized controlled trials. There were no restrictions on language or date of publication. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, including the Cochrane Eyes and Vision Trials Register; 2022, Issue 6), MEDLINE Ovid, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Science Information database), ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) electronic databases. We also examined the reference lists of identified trials, review articles, and guidelines for information about relevant trials that may not have been identified by our search strategy. We contacted investigators regarding ongoing trials. The last database search was performed on 24 October 2022.

SELECTION CRITERIA

We included studies conducted in adults (over 18 years of age) with DED or MGD as defined by the primary trial investigators. We imposed no restrictions on race, ethnicity, or sex. We considered trials involving contact lens wearers if they were equally represented between groups.

DATA COLLECTION AND ANALYSIS

We applied standard Cochrane methodology.

MAIN RESULTS

We included 13 trials that randomized a total of 1155 participants (28 to 236 participants randomized per study). Six trials were conducted in the USA, three in China, two in Thailand, one in France, and one in Italy. Eight trials were of single-center design, while four trials were of multicenter design; one trial did not report the number of participating centers. Study characteristics The study population of the included trials was 66% female (range 48% to 80%), with an age range of 19 to 86 years. LipiFlow, used as a stand-alone intervention, was compared with basic warm compresses in five studies, thermostatic device in five studies, oral intervention in one trial, and topical dry eye medications in one trial. LipiFlow was also evaluated together with eyelid hygiene product versus eyelid hygiene products alone in one trial. Findings Five trials compared LipiFlow with a basic warm compress applied for varying durations and frequencies during the trial period; only one of these trials combined a warm compress with eyelid massage. Analyzing symptom scores by different questionnaires (Ocular Surface Disease Index [OSDI] and Standard Patient Evaluation of Eye Dryness [SPEED]) yielded conflicting evidence of a difference in symptoms between LipiFlow and basic warm compresses after four weeks. There was no evidence of a difference in meibomian gland expression, meibum quality, or tear breakup time when comparing LipiFlow with basic warm compresses. Another five trials compared LipiFlow with thermostatic devices. Analysis of symptom scores at four weeks showed that thermostatic devices had reduced OSDI scores by a mean difference (MD) of 4.59 (95% confidence interval [CI] 1.23 to 7.95; I2 = 0, P = 0.007; 553 participants; very low certainty evidence) as compared with LipiFlow. When we compared LipiFlow plus eyelid hygiene with eyelid hygiene alone, there was no evidence of difference in signs or symptoms at any time point evaluated. Only one trial compared LipiFlow with a topical DED medication (lifitegrast 5%). The single-trial estimate suggested that 5% lifitegrast may increase meibomian gland expression scores compared with LipiFlow at day 42 (MD -1.21, 95% CI -2.37 to -0.05; 50 participants; low certainty evidence) by using a meibomian gland expression scale of 0 to 8. One trial compared LipiFlow with an oral intervention (doxycycline), finding that LipiFlow may result in significantly better SPEED scores than doxycycline at three months (MD -4.00, 95% CI -7.33 to -0.67; 24 participants; very low certainty evidence). No other significant differences in signs or symptoms were found between LipiFlow and doxycycline at three months. We did not find any other statistically significant differences in symptoms or signs for any other analysis performed in this review at the one- to four-week time point. Adverse events No trial reported any intervention-related, vision-threatening adverse events.

AUTHORS' CONCLUSIONS

LipiFlow performs similarly to other commonly used DED treatments with regard to DED signs and symptoms. The best available evidence was deemed to have a high level of bias, leading to low or very low certainty evidence. Additional research with adequate masking, a standardized testing methodology, and a sample representative of the MGD population is therefore needed before any firm conclusions can be drawn regarding comparative benefits and harms.

Spatio-temporal control of targeted gene expression in combination with CRISPR/Cas and Tet-On systems in Medaka

Spatial and temporal control of transgene expression is a powerful approach to understand gene functions in specific cells and tissues. The Tet-On system is a robust tool for controlling transgene expression spatially and temporally; however, few studies have examined whether this system can be applied to postembryonic stages of Medaka (Oryzias latipes) or other fishes. Here, we first improved a basal promoter sequence on the donor vector for a nonhomologous end joining (NHEJ)-based knock-in (KI) system. Next, using transgenic Medaka for establishing the Tet-On system by KI, we demonstrated that doxycycline administration for four or more days by feeding can be a stable and efficient method to achieve expression of the transduced reporter gene in adult fish. From these analyses, we propose an optimized approach for a spatio-temporal gene-expression system in the adult stage of Medaka and other small fishes.

Sexually Transmitted Infection Prevention Perspectives in Black Men Who Have Sex With Men Taking Preexposure Prophylaxis in New Orleans

INTRODUCTION

Profound sexual health disparities exist for Black men who have sex with men (MSM) in the US South, including a high prevalence of sexually transmitted infections (STIs). Sexually transmitted infection prevention strategies beyond condoms are needed for Black MSM taking preexposure prophylaxis (PrEP).

METHODS

We conducted in-depth interviews with Black MSM taking PrEP in New Orleans, Louisiana. Informed by the Health Belief Model, we asked about participants' perceived susceptibility, severity, and concerns regarding STIs, and perceived benefits of STI prevention. We also asked about willingness to use various STI prevention strategies, including antibiotic prophylaxis. Interviews were audio-recorded and analyzed using applied thematic analysis.

RESULTS

We interviewed 24 Black MSM aged 18 to 36 years; half had a recent STI diagnosis. Most participants were concerned about receiving an STI diagnosis, noting shame or disappointment; physical effects were concerning but infrequently considered. Participants described being less likely to use condoms with routine partners or those taking PrEP. Most reported being willing to engage in each of the 6 prevention strategies discussed.

CONCLUSIONS

Black MSM taking PrEP voiced concern about STIs, and many noted that they infrequently use condoms. They were willing to engage in methods focused on preventing STIs on an individual or population level.

Periprosthetic hip infections caused by Brucella: a rare case report and literature review

Periprosthetic hip infection caused by Brucella abortus is rare and only a few cases have been reported. This current case report presents a case of a man in his early 50s who developed periprosthetic hip infection 2 years after right hip arthroplasty. There was no fever or pain, the usual cardinal signs of infection, except for a sinus tract at the previous surgical incision. Laboratory and arthrocentesis culture examinations (done twice) confirmed infection with B. abortus. Accordingly, a two-stage revision surgery was performed accompanied by antibiotic treatment with doxycycline and rifampicin after each stage. There was no recurrence at the 2-year follow-up, with good functional recovery of the hip joint. Clinically, this case serves to highlight the fact that periprosthetic hip infections caused by B. abortus might not present with the typical symptoms such as fever or hip pain. Furthermore, this current case involved a chronic sinus tract, so the diagnostic and therapeutic course of this case offers useful insights for managing similar cases in the future. In addition, a review of the literature on the diagnosis and treatment of Brucella-caused periprosthetic hip infection is presented.

Treatment of ocular rosacea: a systematic review

Rosacea is a common chronic skin disease distributed primarily around the central face. Ocular manifestations of rosacea are poorly studied, and estimates of prevalence vary widely, ranging from 6% to 72% in the rosacea population. Treatment options for ocular rosacea include lid hygiene, topical and oral antibiotics, cyclosporine ophthalmic emulsion, oral vitamin A derivatives, and intense pulsed light; however, a direct comparison of treatment methods for ocular rosacea is lacking. This review aims to compare treatment efficacy and adverse events for different treatment modalities in ocular rosacea. We performed a systematic review by searching Cochrane, MEDLINE and Embase. Title, abstract, full text screening, and data extraction were done in duplicate. Sixty-six articles met the inclusion criteria, representing a total of 1,275 patients. The most effective treatment modalities were topical antimicrobials and oral antibiotics, which achieved complete or partial response in 91% (n = 82/90) and 89% (n = 525/580) of patients respectively, followed by intense pulsed light (89%, n = 97/109 partial response), cyclosporine ophthalmic emulsion (87% n = 40/46), and lid hygiene (65%, n = 67/105). Combination treatments achieved a complete or partial response in 90% (n = 69/77). Results suggest that topical antimicrobials, oral antibiotics, intense pulsed light. and cyclosporine were the most efficacious single modality treatments.

Therapie der okulären Rosazea: Eine systematische Literatur-Übersicht: Treatment of ocular rosacea: a systematic review

Die Rosazea ist eine häufige chronische Hauterkrankung, die sich hauptsächlich im mittleren Bereich des Gesichtes manifestiert. Die okulären Manifestationen der Rosazea wurden bisher nur unzureichend untersucht und bereits die Schätzungen der Prävalenz schwanken erheblich zwischen 6% und 72% der Gesamtpopulation aller Rosazea‐Patienten. Zu den Behandlungsmöglichkeiten der okuläre Rosazea gehören die Lidhygiene, topisch anwendbare antimikrobielle Substanzen, topisch oder oral verabreichte Antibiotika und Vitamin‐A‐Derivate, Cisclosporin‐haltige Emulsionen speziell für das Auge und IPL‐Behandlungen (intense pulsed light). Direkte Vergleiche zwischen den verschiedenen Therapieoptionen fehlen jedoch. Ziel dieser Literatur‐Übersicht ist es, die Wirksamkeit und Nebenwirkungen der verschiedenen Behandlungsmöglichkeiten der okulären Rosazea zu vergleichen. Dazu wurden systematische Datenbankrecherchen in Cochrane, MEDLINE und Embase durchgeführt. Titel, Abstrakt, Volltext und Daten wurden jeweils doppelt durchgesehen. Insgesamt erfüllten 66 Artikel mit einer kumulierten Patientenzahl von 1275 Patienten die Einschlusskriterien. Zu den wirksamsten Behandlungsoptionen zählten topisch anwendbare antimikrobielle Substanzen und die orale Gabe von Antibiotika. Damit konnte bei 91% (n  =  82/90) bzw. 89% (n  =  525/580) der Patienten ein vollständiges oder partielles Ansprechen erzielt werden. Es folgten die IPL‐Behandlung (89%, n  =  97/109 partielles Ansprechen), die Ciclosporin‐Augen‐Emulsion (87% n  =  40/46) und die Lidhygiene (65%, n  =  67/105). Kombinationsbehandlungen führten in 90% der Fälle (n  =  69/77) zu einem vollständigen bzw. partiellen Ansprechen. Diese Ergebnisse deuten darauf hin, dass eine topische Therapie mit antimikrobiellen Substanzen, Antibiotika per os, IPL und Ciclosporin‐haltige Emulsionen die effektivsten Einzelmaßnahmen zur Behandlung der okulären Rosazea darstellen.

Development and validation of method for the simultaneous determination of sulfamethazine, trimethoprim and doxycycline in veterinary formulation using high performance liquid chromatography

Sulfamethazine (SMZ), trimethoprim (TMP) and doxycycline (DOXY) are drugs of choice used in the treatment of intestinal and respiratory infections that affect poultry and swine. The aim of this study was develop and validate a simple, sensitive and fast method for the simultaneous determination of SMZ, TMP and DOXY in veterinary formulations by high-performance liquid chromatography. The separation was performed on a Macherey-Nagel C8 analytical column (4 × 125 mm, 5 μm), with a flow rate of 0.5 ml min-1 and detection at 268, 270 and 350 nm, for SMZ, TMP and DOXY, respectively. All measurements were performed in acetonitrile-water (45:55 v/v; pH 3.0). The analytical curves were linear (r > 0.9997) in the concentration range of 5.0-35.0 μg ml-1 for SMZ, 1.0-7.0 μg ml-1 for TMP and 7.0-13.0 μg ml-1 for DOXY. The method proved to be precise, robust, accurate and selective. In accelerated stability, the sample was analyzed for 6 months, with no major variations observed in organoleptic analysis and pH. Therefore, the developed method was proved to be suitable for routine quality control analyses for the simultaneous determination of SMZ, TMP and DOXY in pharmaceutical formulations.

Comparative Study of Azithromycin Versus Doxycycline Effect on the Resistin Level in Periodontitis Patients With Type 2 Diabetes: A Randomized Controlled Clinical Trial

AIM

The present study aimed to determine if azithromycin (AZM) and doxycycline therapy, as an adjunct to scaling and root planning (SRP), modulate host response and improve clinical outcomes in periodontitis patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

Forty-five periodontal sites in 15 periodontitis patients with T2DM received nonsurgical periodontal therapy (NSPT). In Group I, patients were placebo (not receiving any medication), Group II patients received systemic AZM therapy (AZM 250 mg/day for five days), and Group III patients received doxycycline (20 mg twice per day for three months. The resistin level was collected and measured by enzyme-linked immunosorbent assay (ELISA). Gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were recorded at baseline, one-month, and three-month intervals.

RESULTS

All groups showed improvement in clinical parameters and resistin levels throughout the study. The mean resistin level at three months was the highest in Group I and the lowest in Group III. Patients in Group II showed a larger decrease in mean PD than those in Group I and III. Group III had the highest gain in mean CAL, with an increase of 1.78 mm in attachment.

CONCLUSION

Resistin might be a useful indicator of current disease status. In addition, benefits from adjunctive systemic use of AZM and doxycycline have been administered with non-surgical periodontal therapy.

Efficacy of Doxycycline and Ciprofloxacin for Treatment of Pneumonic Tularemia in Cynomolgus Macaques

BACKGROUND

The incidence of pneumonic tularemia is very low; therefore, it is not feasible to conduct clinical efficacy testing of tularemia medical countermeasures (MCMs) in humans. The US Food and Drug Administration's Animal Model Qualification Program under the Drug Development Tools Program is a regulatory pathway for animal models used in MCM efficacy testing and approval under the Animal Rule. The National Institute of Allergy and Infectious Diseases and Biomedical Advanced Research and Development Authority worked together to qualify the cynomolgus macaque model of pneumonic tularemia.

METHODS

Using the model parameters and end points defined in the qualified model, efficacy of the antibiotics doxycycline and ciprofloxacin was evaluated in separate studies. Antibiotic administration, aimed to model approved human dosing, was initiated at time points of 24 hours or 48 hours after onset of fever as an indicator of disease.

RESULTS

Upon aerosol exposure (target dose of 1000 colony-forming units) to Francisella tularensis SchuS4, 80% of vehicle-treated macaques succumbed or were euthanized. Ciprofloxacin treatment led to 10 of 10 animals surviving irrespective of treatment time. Doxycycline administered at 48 hours post-fever led to 10 of 10 animals surviving, while 9/10 animals survived in the group treated with doxycycline 24 hours after fever. Selected surviving animals in both the placebo and doxycycline 48-hour group showed residual live bacteria in peripheral tissues, while there were no bacteria in tissues from ciprofloxacin-treated macaques.

CONCLUSIONS

Both doxycycline and ciprofloxacin were efficacious in treatment of pneumonic tularemia, although clearance of bacteria may be different between the 2 drugs.

Rapid assessment of coverage of doxycycline/azithromycin chemoprophylaxis against leptospirosis following floods, Kozhikode district, Kerala, 2018

BACKGROUND

We estimated coverage of doxycycline chemoprophylaxis (200 mg once weekly) following floods in Kerala, India.

METHODS

A cross-sectional survey was conducted to gather data on exposure to flood or stagnant water and receipt and consumption of chemoprophylaxis.

RESULTS

Of 1573 individuals interviewed, 152 (10%) were exposed to flood water. Among these, 119 (78%) were eligible for chemoprophylaxis. Of those eligible, 58 (38.2% [95% confidence interval 30.8 to 46.1]) reported consuming the prescribed chemoprophylaxis.

CONCLUSIONS

Despite the availability of chemoprophylaxis, consumption was less than ideal. We recommend targeted interventions to improve chemoprophylaxis coverage and public awareness campaigns to enhance its consumption among the affected population.

Combination of Doxycycline with Metronidazole Protects against Pyroptosis in Rats with Endometritis through the Modulation of TLR4/NF-κB Pathway

BACKGROUND

Endometritis is a condition usually resulted from the bacterial infection of uterus, causing pelvic disease, sepsis, shock, uterine necrosis and even death if it is inappropriately treated. The aim of this study is to explore the pathogenesis of endometritis, and investigate whether the combination of doxycycline and metronidazole offers stronger protection against lipopolysaccharide (LPS)-induced endometritis, and decipher more about the mechanisms underlying endometritis-related pyroptosis.

METHODS

Sprague-Dawley (SD) rats were divided into five groups (n = 8 per group): control, model, metronidazole, doxycycline, and combination groups. In control group, the rats were injected with saline, while in other groups, lipopolysaccharide was injected into uterus of the rats to establish endometritis. Hematoxylin-eosin (H&E) staining was performed as part of the histopathological examination of endometrium. The integrity of chromatin and pyroptosis were evaluated by terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay. Western blot and quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) were performed to ascertain the activation of toll-like receptors (TLR4)/nuclear factor-kappa B (NF-κB) pathway by detecting protein levels of phosphorylated p50 (p-p50)/p50, phosphorylated nuclear factor-kappa B (p-NF-κB)/NF-κB, phosphorylated IkappaB (p-IκB), and TLR4 protein and mRNA. Development of pyroptosis was also detected by determining the levels of caspase-1 and caspase-5 through Western blot and qRT-PCR. Enzyme-linked immunosorbent assay (ELISA) was used to detect levels of interleukin (IL)-1β, IL-18, IL-2, IL-4, IL-6 and tumor necrosis factor alpha (TNF-α), and flow cytometry was adopted to determine T-helper (Th)1 and Th2 cell percentage to assess the extent of pyroptosis and Th1/Th2 imbalance.

RESULTS

The uterine of the model group exhibited pathological alterations and higher degree of cell apoptosis. Compared with the control rats, model group showed lower protein levels of p-p50/p50 (p < 0.001), p-NF-κB/NF-κB (p < 0.001), p-IκB (p < 0.001), and TLR4 protein (p < 0.001) and mRNA (p < 0.001). Elevated levels of caspase-1 (p < 0.001), caspase-5 (p < 0.001), IL-1β (p < 0.001), IL-18 (p < 0.001), IL-2 (p < 0.01), TNF-α (p < 0.05) and Th1/Th2 (p < 0.001) as well as reduced levels of IL-4 (p < 0.05) and IL-6 (p < 0.01) were observed in the model group, which could however be reversed by metronidazole (p < 0.01) or doxycycline (p < 0.01), with a more significant effect detected if a combination of the two drugs was administered (p < 0.01).

CONCLUSIONS

The combination of doxycycline and metronidazole protects against rat endometritis by inhibiting TLR4/NF-κB pathway-mediated inflammation and suppressing pyroptosis.

Histidine-capped copper nanoclusters for in situ amplified fluorescence monitoring of doxycycline through inner filter effect

There is a significant need to accurately measure doxycycline concentrations in view of the adverse effects of an overdose on human health. A fluorescence (FL) detection method was adopted and copper nanoclusters (CuNCs) were synthesized using chemical reduction technology. Based on FL quenching with doxycycline, the prepared CuNCs were used to explore a fluorescent nanoprobe for doxycycline detection. In an optimal sensing environment, this FL nanosensor was sensitive and selective in doxycycline sensing and displayed a linear relationship in the range 0.5-200 μM with a detection limit of 0.092 μΜ. A characterization test demonstrated that CuNCs offered active functional groups for identifying doxycycline using electrostatic interaction and hydrogen bonds. Static quenching and the inner filter effect (IFE) resulted in weakness in the FL of His@CuNCs with doxycycline with great efficiency. This suggested nanosensor was revealed to be a functional model for simple and rapid detection of doxycycline in real samples with very pleasing accuracy.

Atypical Presentation of Rocky Mountain Spotted Fever in Pregnancy

Rocky Mountain spotted fever (RMSF) is a common tick-borne disease and can have variable presentation with potentially fatal outcomes when untreated. We describe an atypical presentation of RMSF in the third trimester. A 37-year-old multiparous woman at 31 0/7 weeks' gestation presented normotensive with headaches and fever but no rash or significant tick exposure. She was initially treated for atypical hemolysis, elevated liver enzymes, and low platelet count syndrome but further decompensated, requiring intensive care unit transfer, intubation, and emergent delivery. Doxycycline administration was associated with marked improvement with no significant sequalae to mother or infant. Later convalescent serologies were positive for RMSF. RMSF is a clinically challenging diagnosis in pregnancy. Given significant morbidity and mortality associated with delayed treatment, high suspicion in endemic areas is needed, and prompt antibiotic use with doxycycline should be administered.

Use of Doxycycline to Prevent Sexually Transmitted Infections According to Provider Characteristics

Use of doxycycline to prevent sexually transmitted infections (STIs) may lead to antimicrobial resistance. We analyzed attitudes toward this practice between US providers who commonly and less commonly treat STIs. Providers who more commonly treat STIs are more likely to prescribe prophylactic doxycycline and believe that benefits outweigh potential for increased antimicrobial resistance.

Doxycycline may be more clinically effective in type 2 chronic rhinosinusitis nasal polyp comorbid with asthma

OBJECTIVE

Chronic rhinosinusitis with nasal polyp (CRSwNP) is one of the major phenotypes of chronic rhinosinusitis (CRS) with a high symptom burden. Doxycycline can be used as add-on therapy in CRSwNP. We aimed to evaluate short-term efficacy of oral doxycycline on visual analog scale (VAS) and SNOT-22 (Sino-nasal outcome test) score for CRSwNP.

METHODS

Visual analog score (VAS) for nasal symptoms and total SNOT-22 scores of 28 patients who applied with the diagnosis of CRSwNP and received 100 mg doxycycline for 21 days were analyzed in this retrospective cohort study. Doxycycline efficacy was also evaluated in subgroups determined according to asthma, presence of atopy, total IgE and eosinophil levels.

RESULTS

After 21-day doxycycline treatment, there was a significant improvement in VAS score for post-nasal drip, nasal discharge, nasal congestion, and sneeze, and total SNOT-22 score (p = 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, respectively). No significant improvement was observed in VAS score for the loss of smell (p = 0.18). In the asthmatic subgroup, there were significant improvements in all VAS scores and total SNOT-22 score after doxycycline. In the non-asthmatic subgroup, there was no significant change in any of the VAS scores, but total SNOT-22 score was significantly improved (42 [21-78] vs. 18 [9-33]; p = 0.043). Improvement in VAS score for loss of smell is significant in only some subgroups like asthmatic patients, non-atopic patients, and patients with eosinophil >300 cell/µL.

CONCLUSIONS

Doxycycline can be considered as an add-on treatment for symptom control in patients especially with CRSwNP comorbid with asthma.

Non-steroidal Anti-inflammatory Drug (NSAID)-, Potassium Supplement-, Bisphosphonate-, and Doxycycline-Mediated Peptic Ulcer Effects: A Narrative Review

Peptic ulcers are a common condition that arises from an imbalance between acid production and gastroduodenal protective factors. Various drugs, including non-steroidal anti-inflammatory drugs (NSAIDs), potassium supplements, bisphosphonates, and doxycycline, can increase the development of peptic ulcers. NSAIDs are one of the most common medications prescribed for pain relief, and they also inhibit the formation of cyclooxygenase-1 (COX-1). COX-1 helps in the production of mucus that lines the stomach, so by inhibiting COX-1, NSAIDs reduce the mucus produced by the stomach and increase the likelihood of gastric ulcer formation. Additionally, NSAIDs are acidic, and increasing the amount of any acid in the stomach can result in promoting ulcer development. Potassium supplements are used to reduce the effects of hypertension, decrease the development of kidney stones, and treat hypokalemia. The various types of transporters and channels used to move potassium across cell membranes increase hydrogen being pumped, increasing gastric acid production and ulcer formation. Bisphosphonates are used to treat a variety of skeletal disorders that require inhibition of osteoclast activity. Nitric oxide (NO) has been shown to have a therapeutic effect on gastric ulcers, and some bisphosphonates have been shown to decrease the production of nitric oxide, resulting in increased damage to the gastric mucosa. Finally, doxycycline is a broad-spectrum tetracycline antibiotic that is typically used to treat anthrax poisoning, skin lesions, and sexually transmitted diseases. A harmful adverse effect of doxycycline is the formation of peptic and gastric ulcers related to the drug being highly acidic once it has dissolved.

Comparison of Doxycycline or Minocycline to Sulfamethoxazole-Trimethoprim for Treatment of Stenotrophomonas maltophilia Pneumonia

BACKGROUND

Stenotrophomonas maltophilia is a multidrug-resistant organism with limited antibiotic treatment options. Minocycline and doxycycline may be appropriate, but clinical data are limited.

OBJECTIVE

To compare tetracyclines (minocycline and doxycycline [TCN]) with standard of care, sulfamethoxazole-trimethoprim (TMP-SMZ), in S. maltophilia pneumonia treatment.

METHODS

This retrospective, 2-center study evaluated patients treated for S. maltophilia pneumonia with TCN or TMP-SMZ for clinical success, defined as resolution of leukocytosis, fever, and tachypnea. Patients were classified as treatment with TCN or TMP-SMZ based on definitive agent used for ≥50% of the treatment course and ≥4 days. Inclusion criteria were age ≥18 years, S. maltophilia confirmed on respiratory culture from January 2013 to November 2020, and appropriate definitive antibiotic dosing. Pregnancy, incarceration, S. maltophilia-resistant or intermediate to definitive therapy, and combination therapy for treatment of S. maltophilia pneumonia were exclusion criteria. Secondary outcomes were microbiologic success and recurrence or reinfection within 30 days requiring treatment.

RESULTS

A total of 80 patients were included (21 TCN [15 minocycline, 6 doxycycline], 59 TMP-SMZ). There was no difference in clinical success (28.6% vs 25.4%; P = 0.994), microbiologic success (n = 28, 55.6% vs 66.4%; P = 0.677), or recurrence or reinfection (n = 24, 66.7% vs 26.7%; P = 0.092) between TCN and TMP-SMZ, respectively.

CONCLUSION AND RELEVANCE

Clinical and microbiologic success rates were similar in patients treated with TCN compared with TMP-SMZ for S. maltophilia pneumonia. These data suggest minocycline and doxycycline may be options to treat S. maltophilia pneumonia, but conclusive clinical data continue to be lacking.

Doxycycline Prophylaxis for Skin and Soft Tissue Infections in Naval Special Warfare Trainees, United States1

In 2015, several severe cases of skin and soft tissue infection (SSTI) among US Naval Special Warfare trainees prompted the introduction of doxycycline prophylaxis during the highest-risk portion of training, Hell Week. We performed a retrospective analysis of the effect of this intervention on SSTI incidence and resulting hospital admissions during 2013-2020. In total, 3,371 trainees underwent Hell Week training during the study period; 284 SSTIs were diagnosed overall, 29 of which led to hospitalization. After doxycycline prophylaxis was introduced, admission rates for SSTI decreased from 1.37 to 0.64 admissions/100 trainees (p = 0.036). Overall SSTI rates remained stable at 7.42 to 8.86 SSTIs/100 trainees (p = 0.185). Hospitalization rates per diagnosed SSTI decreased from 18.4% to 7.2% (p = 0.009). Average length of hospitalization decreased from 9.01 days to 4.33 days (p = 0.034). Doxycycline prophylaxis was associated with decreased frequency and severity of hospitalization for SSTIs among this population.

Orexin 2 receptor antagonism sex-dependently improves sleep/wakefulness and cognitive performance in tau transgenic mice

BACKGROUND AND PURPOSE

Tau pathology contributes to a bidirectional relationship between sleep disruption and neurodegenerative disease. Tau transgenic rTg4510 mice model tauopathy symptoms, including sleep/wake disturbances, which manifest as marked hyperarousal. This phenotype can be prevented by early transgene suppression; however, whether hyperarousal can be rescued after onset is unknown.

EXPERIMENTAL APPROACH

Three 8-week experiments were conducted with wild-type and rTg4510 mice after age of onset of hyperarousal (4.5 months): (1) Tau transgene suppression with doxycycline (200 ppm); (2) inactive phase rapid eye movement (REM) sleep enhancement with the dual orexin receptor antagonist suvorexant (50 mg·kg-1 ·day-1 ); or (3) Active phase non-NREM (NREM) and REM sleep enhancement using the selective orexin 2 (OX2 ) receptor antagonist MK-1064 (40 mg·kg-1 ·day-1 ). Sleep was assessed using polysomnography, cognition using the Barnes maze, and tau pathology using immunoblotting and/or immunohistochemistry.

KEY RESULTS

Tau transgene suppression improved tauopathy and hippocampal-dependent spatial memory, but did not modify hyperarousal. Pharmacological rescue of REM sleep deficits did not improve spatial memory or tau pathology. In contrast, normalising hyperarousal by increasing both NREM and REM sleep via OX2 receptor antagonism restored spatial memory, independently of tauopathy, but only in male rTg4510 mice. OX2 receptor antagonism induced only short-lived hypnotic responses in female rTg4510 mice and did not improve spatial memory, indicating a tau- and sex-dependent disruption of OX2 receptor signalling.

CONCLUSIONS AND IMPLICATIONS

Pharmacologically reducing hyperarousal corrects tau-induced sleep/wake and cognitive deficits. Tauopathy causes sex-dependent disruptions of OX2 receptor signalling/function, which may have implications for choice of hypnotic therapeutics in tauopathies.

Chlorhexidine and doxycycline gel versus chip as adjuncts in oral hygiene among Indians

The effectiveness of newly released medications such as Chlorhexidine (CHX) chip, Doxycycline hyclate (DH) chip, CHX gel, DH chip as adjunct to scaling and root planing in the treatment of chronic periodontitis is important. 90 adult Indian patients with moderate chronic periodontitis were enlisted. It was observed that reduction in periodontal pocket depth (PPD) and increase in clinical attachment level (CAL) was seen in patients in CHX group as compared to DH treated study participants. It was observed that CHX and DH in gel form were more effective in improving periodontal health as compared to CHX and DH in chip form in this group of subjects.

Oxidative stress induced by sustained supraphysiological intrastriatal GDNF delivery is prevented by dose regulation

Despite its established neuroprotective effect on dopaminergic neurons and encouraging phase I results, intraputaminal GDNF administration failed to demonstrate significant clinical benefits in Parkinson's disease patients. Different human GDNF doses were delivered in the striatum of rats with a progressive 6-hydroxydopamine lesion using a sensitive doxycycline-regulated AAV vector. GDNF treatment was applied either continuously or intermittently (2 weeks on/2 weeks off) during 17 weeks. Stable reduction of motor impairments as well as increased number of dopaminergic neurons and striatal innervation were obtained with a GDNF dose equivalent to 3- and 10-fold the rat endogenous level. In contrast, a 20-fold increased GDNF level only temporarily provided motor benefits and neurons were not spared. Strikingly, oxidized DNA in the substantia nigra increased by 50% with 20-fold, but not 3-fold GDNF treatment. In addition, only low-dose GDNF allowed to preserve dopaminergic neuron cell size. Finally, aberrant dopaminergic fiber sprouting was observed with 20-fold GDNF but not at lower doses. Intermittent 20-fold GDNF treatment allowed to avoid toxicity and spare dopaminergic neurons but did not restore their cell size. Our data suggest that maintaining GDNF concentration under a threshold generating oxidative stress is a pre-requisite to obtain significant symptomatic relief and neuroprotection.

Pharmacodynamics of zoliflodacin plus doxycycline combination therapy against Neisseria gonorrhoeae in a gonococcal hollow-fiber infection model

Antimicrobial resistance in the sexually transmitted bacterium Neisseria gonorrhoeae is compromising the management and control of gonorrhea globally. Optimized use and enhanced stewardship of current antimicrobials and development of novel antimicrobials are imperative. The first in class zoliflodacin (spiropyrimidinetrione, DNA Gyrase B inhibitor) is a promising novel antimicrobial in late-stage clinical development for gonorrhea treatment, i.e., the phase III randomized controlled clinical trial (ClinicalTrials.gov Identifier: NCT03959527) was recently finalized, and zoliflodacin showed non-inferiority compared to the recommended ceftriaxone plus azithromycin dual therapy. Doxycycline, the first-line treatment for chlamydia and empiric treatment for non-gonococcal urethritis, will be frequently given together with zoliflodacin because gonorrhea and chlamydia coinfections are common. In a previous static in vitro study, it was indicated that doxycycline/tetracycline inhibited the gonococcal killing of zoliflodacin in 6-h time-kill curve analysis. In this study, our dynamic in vitro hollow-fiber infection model (HFIM) was used to investigate combination therapies with zoliflodacin and doxycycline. Dose-range experiments using the three gonococcal strains WHO F (susceptible to relevant therapeutic antimicrobials), WHO X (extensively drug-resistant, including ceftriaxone-resistant; zoliflodacin-susceptible), and SE600/18 (zoliflodacin-susceptible strain with GyrB S467N substitution) were conducted simulating combination therapy with a single oral dose of zoliflodacin 0.5-4 g combined with a doxycycline daily oral dose of 200 mg administered as 100 mg twice a day, for 7 days (standard dose for chlamydia treatment). Comparing combination therapy of zoliflodacin (0.5-4 g single dose) plus doxycycline (200 mg divided into 100 mg twice a day orally, for 7 days) to zoliflodacin monotherapy (0.5-4 g single dose) showed that combination therapy was slightly more effective than monotherapy in the killing of N. gonorrhoeae and suppressing emergence of zoliflodacin resistance. Accordingly, WHO F was eradicated by only 0.5 g single dose of zoliflodacin in combination with doxycycline, and WHO X and SE600/18 were both eradicated by a 2 g single dose of zoliflodacin in combination with doxycycline; no zoliflodacin-resistant populations occurred during the 7-day experiment when using this zoliflodacin dose. When using suboptimal (0.5-1 g) zoliflodacin doses together with doxycycline, gonococcal mutants with increased zoliflodacin MICs, due to GyrB D429N and the novel GyrB T472P, emerged, but both the mutants had an impaired biofitness. The present study shows the high efficacy of zoliflodacin plus doxycycline combination therapy using a dynamic HFIM that more accurately and comprehensively simulate gonococcal infection and their treatment, i.e., compared to static in vitro models, such as short-time checkerboard experiments or time-kill curve analysis. Based on our dynamic in vitro HFIM work, zoliflodacin plus doxycycline for the treatment of both gonorrhea and chlamydia can be an effective combination.

Doxycycline postexposure prophylaxis for prevention of sexually transmitted infections

Doxycycline postexposure prophylaxis (doxy-PEP) is a novel strategy now demonstrated in several clinical trials to dramatically reduce incidence rates of gonorrhea, chlamydia, and syphilis in some key populations at high risk of sexually transmitted infections. Even so, much remains unknown about the long-term consequences of doxy-PEP, and several concerns, including the potential for the development of antibiotic resistance and disturbances to the microbiome, balance the benefits. This review highlights the history of antibiotic prophylaxis for sexually transmitted infections, and the rationale, current evidence, and future directions for doxy-PEP.

Doxycycline-Induced Intracranial Hypertension Presenting as Unilateral Pulsatile Tinnitus

Background

Pulsatile tinnitus (PT) is increasingly recognized as a cardinal symptom of idiopathic intracranial hypertension (IIH). However, clinicians should remain aware of other causes of nonidiopathic or secondary intracranial hypertension manifesting as PT. We present 2 patients with isolated PT (without accompanying headache, blurred vision, and papilledema) thought to be secondary to tetracycline-induced intracranial hypertension. To our knowledge, these are the first cases of PT as the presenting symptom of this condition.

Cases

A 41-year-old female (body mass index [BMI] 29 kg/m2) with ocular rosacea was initially treated with minocycline. Shortly after transitioning to oral doxycycline and erythromycin eye ointment, she noted left-sided PT. Her PT resolved after discontinuing doxycycline. In a second case, a 39-year-old female (BMI 19 kg/m2) with acne presented with a three-year history of left-sided PT while on long-term oral doxycycline for many years. She denied visual or auditory changes and atypical headaches. MRI findings were concerning for intracranial hypertension. Three months later, the patient was seen by neuro-ophthalmology, with findings suggesting prior papilledema. The patient reported PT improvement after discontinuing doxycycline.

Conclusions

This case series highlights 2 cases of isolated PT as the sole symptom of intracranial hypertension that resolved with tetracycline cessation. The presentation and unexpected improvement following tetracycline discontinuation are atypical compared with previous reports of tetracycline-induced intracranial hypertension. Clinicians should maintain a high index of suspicion for all types of intracranial hypertension (idiopathic and secondary), even in patients with a lower BMI. Current and prior medications should be reviewed when considering the etiology of intracranial hypertension.