The efficacy, safety, and feasibility of inhaled amikacin for the treatment of difficult-to-treat non-tuberculous mycobacterial lung diseases

Background

In multidrug regimens, including an intravenous aminoglycoside (e.g. amikacin [AMK]) is recommended for difficult-to-treat non-tuberculous mycobacterial (NTM) lung diseases. We aimed to evaluate the efficacy, safety, and feasibility of inhaled AMK therapy in patients with difficult-to-treat NTM lung diseases in a retrospective chart review.

Methods

The study population consisted of patients with NTM lung diseases who received combination therapy, including inhaled AMK therapy, at Keio University Hospital (Tokyo, Japan), from January 2014 through May 2016. A total of 26 cases, consisting of 23 Mycobacterium avium complex (MAC) and three Mycobacterium abscessus complex (MABC) infections cases, were included in this study. The efficacy, safety, and feasibility of inhaled AMK therapy were retrospectively investigated. The Research Ethics Committee of Keio University Hospital approved this study, and informed consent was obtained from all patients.

Results

All 26 patients were culture-positive at enrolment. Twenty-three of the 26 patients (88.5%), including 21/23 MAC patients (91.3%) and 2/3 MABC patients (66.7%), were administered inhaled AMK therapy for >3 months. The proportion of patients who had clinical symptoms, including, cough and sputum, declined after inhalation AMK therapy. Ten of the 23 patients (43.5%) who received AMK inhalation, including 8/21 MAC (38.1%) and 2/2 MABC patients (100%), showed sputum conversion, defined as at least three consecutive negative sputum cultures. Seven of the 23 patients, including, 5/21 MAC and 2/2 MABC patients, showed improvements in high-resolution computed tomography imaging of the chest. In addition, the serum AMK trough levels before the second inhalation were <1.2 μg/mL in all 26 patients, with no occurrence of severe adverse events, such as renal toxicity. One patient (3.8%) experienced auditory toxicity, in the form of tinnitus. However, this symptom was reversible, after temporary interruption of AMK, the patient was able to safely resume the therapy.

Conclusions

Inhaled AMK therapy is an effective and feasible therapy for difficult-to-treat NTM lung disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2665-5) contains supplementary material, which is available to authorized users.

Stability of benzylpenicillin potassium and ampicillin in an elastomeric infusion pump

Some infectious diseases, such as infective endocarditis, osteomyelitis, and abscesses, require treatment with long-term intravenous antimicrobial treatment. Therefore, the patient is required to stay in the hospital to receive therapy, which lowers their quality of life. Establishing an outpatient parenteral antimicrobial therapy (OPAT) by continuous infusion pump is desired in Japan to overcome these issues. However, the 24-h stability of antimicrobial agents dissolved in infusion solutions is unclear. Thus, we investigated the stability of antimicrobial agents in five different infusion solutions in a clinical setting. Benzylpenicillin potassium (PCG) and ampicillin (ABPC) were dissolved separately in five different infusion solutions and kept at 25 or 31.1 °C for 24 h. The residual ratios were determined by high-performance liquid chromatography (HPLC). Dissolved PCG in acetate ringer solution remained stable for 24 h at temperatures of 25 and 31.1 °C (101.7 ± 1.4% and 92.9 ± 1.3%, respectively). In addition, the PCG solution did not adsorb onto the elastomeric infusion pump after 24 h at 31.1 °C. PCG dissolved in acetate ringer solution was also stable for 10 days after being kept in an elastomeric infusion pump at 4 °C (99.7 ± 0.5%). ABPC was unstable in all of the tested infusion solutions and temperatures. Based on our results, PCG in acetate ringer solution can be used in OPAT with continuous infusion pumps.

Stability of antimicrobial agents in an elastomeric infusion pump used for outpatient parenteral antimicrobial therapy

OBJECTIVES

The long-term stability of antimicrobials dissolved in infusion solution is necessary to establish and spread the outpatient parenteral antimicrobial therapy (OPAT). In this study, we evaluated the stability of antimicrobial agents dissolved in infusion solutions.

METHODS

The antimicrobial agents were dissolved in infusion solutions and kept at 25 °C and 31.1 °C for 24 h or 4 °C for 10 days in a polypropylene tube or an elastomeric infusion pump. The stability was measured by high-performance liquid chromatography.

RESULTS AND CONCLUSION

The residual ratio of cefazolin (CEZ), cefmetazole (CMZ), piperacillin (PIPC), and tazobactam (TAZ) at 31.1 °C for 24 h was as follows: 95.7 ± 3.0%, 94.8 ± 0.9%, 102.6 ± 1.8%, and 103.9 ± 3.6% in saline, respectively; 94.7 ± 3.0%, 94.3 ± 1.5%, 106.1 ± 3.0%, and 107.3 ± 2.4% in 5% dextrose solution, respectively. The residual ratio of these antimicrobials at 4 °C for 10 days was maintained above 90% in both saline and 5% dextrose solution. The residual ratio of all the above antimicrobials in an elastomeric infusion pump at 31.1 °C for 24 h was equivalent to that in the polypropylene tube. On the other hand, doripenem and meropenem were not stable in any infusion solution at 31.1 °C. CEZ, CMZ, and PIPC/TAZ dissolved in saline or 5% dextrose solution can be used in OPAT with continuous infusion pumps.

Evaluation for optimal dosing of vancomycin in patients with different physical types

The sufficient dose to obtain an optimal trough concentration of vancomycin (VCM) in patients with non-standard physical types remains controversial. In this study, we examined the relationship between the dose and physical type in patients in whom an optimal trough concentration was obtained among VCM-treated patients. We retrospectively investigated the dose of VCM and physical type in patients treated with VCM between January 2012 and January 2017 at two medical institutions (n = 272). The physical type was classified using the body mass index (BMI). Patients with a BMI of <18.5 kg/m² were assigned to the lean group, those with a BMI of 18.5-24.9 kg/m² were assigned to the standard group, and those with a BMI of ≥25 kg/m² were assigned to the obesity group. The mean doses of VCM per time (mg/kg) to achieve the target trough concentration of VCM, 15-20 μg/mL, were 19.8 ± 4.3, 16.5 ± 3.7, and 13.7 ± 2.7 mg/kg in the lean, standard, and obesity groups, respectively. The dose per time to achieve the target trough concentration decreased significantly in association with an increase of BMI. The upper limit of the recommended dose (15-20 mg/kg) or higher in lean patients, and the lower dose in obese patients than the recommended dose might be appropriate to achieve the target trough concentration when we calculated the dose per time based on actual body weight.

Pharmacokinetics of intravenous peramivir in the airway epithelial lining fluid of healthy volunteers

BACKGROUND

Some subtypes of influenza virus, such as H5N1 and H7N9, cause severe viral pneumonia, for which the intraluminal concentration of the anti-influenza agent in the airway is critical. However, the pharmacokinetics of peramivir, the only available injectable neuraminidase inhibitor formulation, in the airway epithelial lining fluid (ELF) remains unclear. In this study, we aimed to determine the time course of peramivir in the pharyngeal ELF, bronchial ELF and plasma of healthy volunteers using bronchoscopic microsampling technique.

METHODS

Six healthy volunteers were studied. After baseline plasma sampling, 0.3 g peramivir was intravenously injected over 0.5 h. ELF was obtained from the upper and lower airways using bronchoscopic microsampling at the end of the infusion (0.5 h) and after 1.0, 1.5, 2.0, 2.5, 3.0, 4.0 and 5.0 h. The concentrations of peramivir in the ELFs and in the plasma were quantified by LC/MS/MS analysis.

RESULTS

The mean maximum concentration (C_max) in pharyngeal ELF, bronchial ELF and plasma was 1.20 ±0.42, 9.60 ±2.30 and 50.52 ±17.51 ng/ml, respectively. The penetration ratio at C_max in pharyngeal and bronchial ELFs was 2.4 and 19.0, respectively. The ratio of the area under the curve from 0 to infinity in pharyngeal and bronchial ELFs was 4.8 and 39.1 mg•min/l, respectively.

CONCLUSIONS

The time course of peramivir concentration in the ELFs revealed that concentrations above the 50% inhibitory concentration value of influenza were achieved in the upper and lower airways. Therefore, peramivir could be an important treatment option for influenza viral pneumonia.

Safety and efficacy of linezolid in 16 infants and children in Japan

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It has been licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients. At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolid owing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severe underlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid. Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, or intravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median duration of administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could be evaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showed elevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring that administration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. The other patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for children in Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics for infections with multidrug-resistant Gram-positive bacteria.

Nephrotoxicity of concomitant use of tacrolimus and teicoplanin in allogeneic hematopoietic stem cell transplant recipients

Both tacrolimus and glycopeptide antibiotics are known to be nephrotoxic, and are often concomitantly given after hematopoietic stem cell transplantation (HSCT) or solid organ transplantation. The aim of this study is to evaluate the nephrotoxicity of concomitant use of tacrolimus and glycopeptide antibiotics in HSCT recipients. We retrospectively evaluated 67 patients who received intravenous tacrolimus and teicoplanin concomitantly for >4 days after allogeneic HSCT for hematologic diseases. Therapeutic drug monitoring (TDM) was performed in all patients for both tacrolimus and teicoplanin. The median age of the patients was 48 years (range: 16-62), and the median duration of the co-administration of tacrolimus and teicoplanin was 11 days (range: 4-40). The mean serum creatinine (sCr) level tended to be elevated after the co-administration (from 0.69 ± 0.26 to 0.75 ± 0.30 mg/dL; P = 0.08); however, a 2-fold or greater increase in sCr was observed only in 2 (3.0%) patients. Increased sCr was reversible, and no patient required hemodialysis. These results suggest that the incidence of clinically significant nephrotoxicity can be minimized if the TDM of each drug is properly applied.

Clinical features of bacteremia due to Campylobacter jejuni

OBJECTIVE

The clinical features of bacteremia due to Campylobacter jejuni (C. jejuni) have yet to be fully elucidated.

METHODS AND RESULTS

The cases of C. jejuni bacteremia were retrospectively reviewed during a twelve-year period in a single institute. C. jejuni was identified in 7 patients through blood cultures, and disease onset occurred between June and October. Except for 2 previously healthy individuals, 5 patients had underlying diseases (chronic liver diseases, n=3; hematological malignancies, n=2). All patients were febrile, but 2 patients did not present with gastrointestinal symptoms. C. jejuni isolates were susceptible to gentamicin and macrolides, but about half of them were resistant to fluoroquinolones. Disease outcomes were favorable, and no deaths related to C. jejuni bacteremia were observed.

CONCLUSION

These results suggest that C. jejuni bacteremia could occur primarily or secondarily to gastroenteritis with a seasonal peak and that prognosis would be favorable regardless of the underlying diseases.

Retrospective study of the efficacy and safety of metronidazole and vancomycin for Clostridioides difficile infection

INTRODUCTION

According to the Japanese guidelines for the management of Clostridioides difficile infection (CDI), the first choice is metronidazole (MNZ) for non-severe cases and vancomycin (VCM) for severe cases. However, the appropriateness of this first choice in Japanese patients is unclear. We therefore evaluated the appropriateness of the CDI management guidelines and the incidence of adverse drug reactions.

METHODS

The electronic chart data at Keio University Hospital between January 2012 and June 2019 were retrospectively reviewed. The response rate, the relapse rate, and the adverse reaction rate of treatment for CDI using MNZ or VCM were investigated according to the disease severity. Factorial analysis associated with the response, relapse, and adverse reaction was also performed.

RESULTS

In the 352 patients surveyed, no significant difference was observed in the response rate between MNZ and VCM regardless of the severity of CDI. The presence of cancer was a factor related to the persistence of diarrheal symptoms and older age was a risk factor for relapse. MNZ induced nausea significantly more frequently than VCM, and young age and female sex were risk factors for nausea.

CONCLUSION

As no significant difference was observed in the response rate of CDI between MNZ and VCM, the Japanese CDI management guidelines, which recommend MNZ as the first choice, were demonstrated to be appropriate. Attention to nausea was also suggested to be necessary when administering MNZ to young females.

Pharmacokinetics and skin-tissue penetration of daptomycin in rats

Background

Daptomycin is recommended for complicated skin and skin-structure infections. However, information on the penetration of daptomycin into skin is limited. Therefore, the aim of this in vivo investigation was to determine the pharmacokinetics and skin penetration of daptomycin in rats.

Materials and methods

Concentrations of daptomycin were determined by high-performance liquid chromatography. A noncompartmental pharmacokinetic analysis was conducted to estimate the rate and extent of daptomycin penetration from the systemic circulation into skin tissue. Since protein binding of daptomycin in rat serum was 89.3%, the free maximum concentration (C_max) and free area under the curve from time 0 to infinity (AUC_0–∞) for plasma were calculated as follows: fC_{max, plasma} = (1 – 0.893) × C_{max, plasma}, fAUC_{0–∞, plasma} = (1 – 0.893) × AUC_{0–∞, plasma}.

Results

The following values (mean ± standard deviation) were obtained: 0.06±0 L/h/kg for total clearance (CL_total), 0.44±0.06 hours for elimination-rate constant, 1.58±0.23 hours for half-life, 0.14±0.02 L/kg for steady-state volume distribution, and 2.28±0.33 hours for mean residence time. Time to C_max was 3.0 hours for plasma and skin tissue. C_max and AUC_0–∞ for plasma were 175.8±5.1 μg/mL and 811.8±31.9 μg × h/mL, respectively. C_max and AUC_0–∞ for skin tissue were 19.1±1.7 μg/mL and 113.9±21.8 μg × h/mL, respectively. Furthermore, fC_max and fAUC_0–∞ for plasma were 18.8 μg/mL and 86.9 μg × h/mL, respectively. The degrees of skin-tissue penetration, defined as the C_{max, skin tissue}/fC_{max, plasma} ratio and AUC_{0–∞, skin tissue}/fAUC_{0–∞, plasma} ratio, were 1.0 and 1.3, respectively.

Conclusion

Daptomycin exhibited good penetration into skin tissue, supporting its use for the treatment of complicated skin and skin-structure infections. However, further studies are needed in infected patients in order to investigate the relationship between the antimicrobial efficacy of daptomycin and its drug concentrations in skin tissues.

Impact of rifampicin on the pharmacokinetics of clarithromycin and 14-hydroxy clarithromycin in patients with multidrug combination therapy for pulmonary Mycobacterium avium complex infection

INTRODUCTION

Clarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) combination therapy is used to treat pulmonary Mycobacterium avium complex (MAC) infection; however, serum CAM concentration decreases due to RFP-mediated induction of CYP3A activity. Therefore, we investigated the pharmacokinetics of CAM, 14-hydroxy clarithromycin (14-OH CAM), EB, and RFP in patients receiving this three-drug combination therapy.

METHODS

CAM monotherapy was started, EB was added 2 weeks later, and RFP was added 2 weeks after that. Serum CAM, 14-OH CAM, EB, and RFP concentrations were measured before and at 2, 4, 6, and 12 or 24 h after administration on days 14, 28, and 42, and pharmacokinetic parameters were calculated.

RESULTS

Median area under the curve (AUC) of CAM decreased by 92.1% from 0 to 12 h after concomitant administration of RFP compared with CAM monotherapy [1.7 (interquartile range [IQR], 1.4-1.8) μg·h/mL vs. 21.5 (IQR, 17.7-32.3) μg·h/mL, respectively]. In contrast, median AUC of 14-OH CAM was not significantly different between concomitant administration of RFP [9.1 (IQR, 7.9-10.9) μg·h/mL] and CAM monotherapy [8.2 (IQR, 6.3-9.3) μg·h/mL]. AUCs of CAM and 14-OH CAM did not change in CAM+EB combination therapy.

CONCLUSIONS

When RFP is combined with CAM in the treatment of pulmonary MAC infection, the blood concentration of CAM significantly decreased and that of the active metabolite 14-OH CAM increased, but not significantly. Our results suggest that combination therapy with CAM and RFP needs to be reconsidered and may require dose modification in the treatment of pulmonary MAC infection.

[Variability in drug response caused by the genetic polymorphisms of receptors]

A greater deal of attention has been given to the genetic polymorphism of receptors and related variability in drug response. In recent years, studies on pharmacogenomics accomplished remarkable progress in this issue. These studies include, the relationships between beta 2-adrenegic receptor polymorphism and the pharmacological effect of blonchodilator, dopamine D2 or 5-HT2 receptor polymorphism and response to antipsychotic medication, vitamin D receptor variants and the active vitamin D therapy, PPAR gamma and the insulin resistance treatment and so on. However, some of them are still controversial, and it requires further investigation to apply these studies to the actual therapy.

Analysis of Risk Factors for Developing Tuberculosis in Patients Who Received Prophylactic Latent Tuberculosis Infection Treatment with Experience of Biologic Medications

Biologic medications have dramatically improved the treatment outcomes of immunological inflammatory diseases, but their immunosuppressive effects put patients at risk for tuberculosis (TB). We investigated the risk factors for developing TB in patients treated for latent tuberculosis infection (LTBI) who also had experience of using biologic medications. At Keio University Hospital, we retrospectively investigated patients treated with anti-mycobacterial drugs before or concurrently with biologic medications from January 2012 to August 2020. Patients in the 'follow-on cases group' who had a positive TB screening test after initiating biologic medications and subsequently started LTBI treatment were excluded. We researched and compared the patient characteristics for TB and non-TB patient groups. Of the 146 eligible patients, 5 (3.4%) developed TB. The incidence rate was 600/100000 person-years. There were no significant differences between TB and non-TB patient groups in the history of TB, interferon-gamma release assay (IGRA), duration of biologic medication therapy, LTBI treatment periods, concomitant use of calcineurin inhibitors or anti-rheumatic drugs. The percentage of patients who received prednisolone at a dose of ≥15 mg for more than 1 month was higher in those who developed TB than in those who did not (40.0 vs. 7.1%, p = 0.054); however, this difference was not statistically significant. Regular monitoring of TB is necessary for long-term concomitant use of high prednisolone doses during and after the administration of biologic medications.

Possible involvement of distinct phylogenetic clusters of HIV-1 variants in the discrepancies between coreceptor tropism predictions based on viral RNA and proviral DNA

Background

The coreceptor tropism testing should be conducted prior to commencing a regimen containing a CCR5 antagonist for treatment of HIV-1 infection. For aviremic patients on long antiretroviral therapy, proviral DNA is often used instead of viral RNA in genotypic tropism testing. However, the tropism predictions from RNA and DNA are sometimes different. We examined the cause of the discrepancies between HIV-1 tropism predictions based on viral RNA and proviral DNA.

Methods

The nucleotide sequence of the env C2V3C3 region was determined using pair samples of plasma RNA and peripheral blood mononuclear cell DNA from 50 HIV-1 subtype B-infected individuals using population-based sequencing. The samples with discrepant tropism assessments between RNA and DNA were further analyzed using deep sequencing, followed by phylogenetic analysis. The tropism was assessed using the algorithm geno2pheno with a false-positive rate cutoff of 10 %.

Results

In population-based sequencing, five of 50 subjects showed discrepant tropism predictions between their RNA and DNA samples: four exhibited R5 tropism in RNA and X4 tropism in DNA, while one exhibited the opposite pattern. In the deep sequencing and phylogenetic analysis, three subjects had single clusters comprising of RNA- and DNA-derived sequences that were a mixture of R5 and X4 sequences. The other two subjects had two and three distinct phylogenetic clusters of sequences, respectively, each of which was dominated by R5 or X4 sequences; sequences of the R5-dominated cluster were mostly found in RNA, while sequences of the X4-dominated cluster were mostly in DNA.

Conclusions

Some of HIV-1 tropism discrepancies between viral RNA and proviral DNA seem to be caused by phylogenetically distinct clusters which resides in plasma and cells in different frequencies. Our findings suggest that the tropism testing using PBMC DNA or deep sequencing may be required when the viral load is not suppressed or rebounds in the course of a CCR5 antagonist-containing regimen.

Direct comparison of the effects of first- and second-generation H1 -receptor blockers on motor functions in mice

Histamine H1 receptor (H1R) antagonists are widely used to treat allergic reactions; however, their effects on the central nervous system can impair motor functions. This study investigated the impact of first-generation (diphenhydramine and d -chlorpheniramine) and second-generation (epinastine, ketotifen, bepotastine, and levocetirizine) H1R antagonists on motor functions in mice using activity wheel, balance beam, inclined screen, and rotarod tests. First-generation H1R antagonists significantly impaired motor functions, with diphenhydramine exerting stronger effects than those of d -chlorpheniramine. Among the second-generation agents, bepotastine and levocetirizine had minimal effects on all motor functions, whereas epinastine and ketotifen suppressed spontaneous movement, similar to first-generation H1R antagonists but had little effects on balance, postural stability, and coordinated movement. These findings provide valuable insights into the differential effects of first- and second-generation H1R antagonists on motor functions. These results highlight the importance of understanding individual profiles of H1R antagonists to minimize adverse effects, ensure patient safety, and improve quality of life.

Digestive Decolonization of Colorectal Carriage of Vancomycin-resistant Enterococcus faecium in a Japanese Adult

Patients with vancomycin-resistant Enterococcus (VRE) colonization should be managed in an isolation room with contact precautions. We herein report a patient whose colorectal carriage of VRE was successfully decolonized using concomitant bowel irrigation with polyethylene glycol, probiotics, and oral antimicrobials, linezolid and orally-administered daptomycin, for release from isolation and contact precautions. We therefore would like to suggest a potential strategy for managing patients with VRE colonization.

[Appropriate hemodialysis scheduling based on therapeutic drug monitoring of carboplatin in a patient with lung cancer and chronic renal failure]

A 69-year-old woman undergoing hemodialysis due to ANCA-associated nephritis and chronic renal failure developed lung adenocarcinoma and underwent radical surgery. Upon recurrence of her cancer, she received combination chemotherapy with carboplatin (CBDCA) 150 mg/m2 and docetaxel 35-70 mg/m2. Concentration of free CBDCA in serum was monitored for 6 days after drug administration. Hemodialysis was performed 1 hour after administration of CBDCA, and on day 4. Despite the lower maximum concentration, serum CBDCA levels 20-24 h after chemotherapy in this patient were 15 to 20 times higher than in subjects with normal renal function who received CBDCA at the area under the curve (AUC) of 5. She experienced moderate to severe nausea and vomiting which persisted for 12 days. During her second course of chemotherapy, hemodialysis was performed for 3 consecutive days after drug administration. The serum CBDCA levels on day 2 or later remained lower than in the first course, and the patient experienced fewer severe side effects. Based on the data from therapeutic drug monitoring of CBDCA, hemodialysis for 3 consecutive days after drug administration has been demonstrated to be useful for treatment of a patient with chronic renal failure receiving chemotherapy with CBDCA.

Anti-edematous effects of epinastine, cetirizine and its enantiomers in λ-carrageenan-induced edema in rat hind paw

Urticaria is induced by the histamine released from mast cells which develops wheals (edema) as a visual feature. In clinical practice, second-generation histamine H1 -receptor blockers are routinely used as the first-line symptomatic treatment for urticaria. Nevertheless, not much research has directly examined the second-generation histamine H1-receptor blockers' ability to reduce edema. In this study, we directly evaluated the anti-edematous activities of three second-generation histamine H1-receptor blockers available in the market (epinastine hydrochloride, cetirizine hydrochloride, and levocetirizine hydrochloride) using a λ-carrageenan-induced footpad edema model. One hour before the induction of edema with 1% λ -carrageenan injection, all second-generation histamine H1 -receptor blockers (5, 10, 50 and 100 mg/kg) were subcutaneously administered to rats. At 0.5 and 3 hours after λ -carrageenan administration, the edema volume was evaluated using a Plethysmometer. Epinastine hydrochloride significantly suppressed the edema growth in a dose-dependent manner. Cetirizine hydrochloride showed a slight anti-edematous effect, while levocetirizine significantly inhibited the development of edema in a dose-dependent manner. On the other hand, dextrocetirizine did not prevent edema from growing. In summary, second-generation histamine H1 -receptor blockers, at least those examined in this study, may be able to reduce the clinical symptoms of urticaria associated with edema. Levocetirizine hydrochloride is also anticipated to have stronger anti-edematous effects than cetirizine hydrochloride because levocetirizine is responsible for cetirizine's anti-edematous activity.

Direct comparison of anti-inflammatory effects of 14-, 15-, and 16-membered macrolide antibiotics in experimental inflammation model induced by carrageenan in rats

Some macrolide antibiotics, which share a basic lactone ring structure, also exhibit anti-inflammatory actions in addition to their antibacterial activities. However, no study has directly compared anti-inflammatory effects on acute inflammation among macrolide antibiotics with the distinct size of the lactone ring. In this study, we evaluated and compared the anti-inflammatory activities of four 14-membered macrolides (erythromycin, clarithromycin, roxithromycin, oleandomycin), one 15-membered macrolide (azithromycin), and three 16-membered macrolides (midecamycin, josamycin, leucomycin) using a rat carrageenan-induced footpad edema model. All macrolide antibiotics were intraperitoneally administered to rats one hour before the induction of inflammatory edema with 1% λ -carrageenan. The anti-inflammatory effects on acute inflammation were evaluated by changing the edema volume. All 14-membered and 15-membered macrolide antibiotics significantly suppressed the development of edema. Conversely, none of the 16-membered macrolide antibiotics inhibited the growth of edema. In conclusion, compared to 16-membered macrolide antibiotics, 14-membered and 15-membered macrolide antibiotics have stronger anti-inflammatory effects. Further research should be done to determine why different lactone ring sizes should have distinct anti-inflammatory effects.