Recognizing doxycycline-induced esophageal ulcers in dental practice: a case report and review

The Impact of Long-Term Antibiotic Therapy of Cutaneous Adverse Reactions to EGFR Inhibitors in Colorectal Cancer Patients

Colorectal cancer (CRC) is an important public health issue, in terms of incidence and mortality, with approximately 1.8 million new cases reported worldwide in 2018. Advancements in understanding pathophysiological key steps in CRC tumorigenesis have led to the development of new targeted therapies such as those based on epidermal growth factor receptor inhibitors (EGFR inhibitors). The cutaneous adverse reactions induced by EGFR inhibitors, particularly papulopustular rash, often require long-term antibiotic treatment with tetracycline agents (mostly minocycline and doxycycline). However, this raises several issues of concern: possible occurrence of gut dysbiosis in already vulnerable CRC patients, selection of highly antibiotic resistant and/or virulent clones, development of adverse reactions related to tetracyclines, interference of antibiotics with the response to oncologic therapy, with a negative impact on disease prognosis etc. In the context of scarce information regarding these issues and controversial opinions regarding the role of tetracyclines in patients under EGFR inhibitors, our aim was to perform a thorough literature review and discuss the main challenges raised by long-term use of tetracyclines in advanced CRC patients receiving this targeted therapy.

Oesophageal ulceration in adult patients treated with doxycycline for acne vulgaris

Objective

To report drug-induced oesophageal ulceration in adult patients treated with doxycycline for acne vulgaris.

Methods

This retrospective case series included data from adult patients treated with oral doxycycline therapy for acne vulgaris, who had presented with oesophageal ulceration at the Third People’s Hospital of Hangzhou between June 2016 and December 2017, and whose diagnosis was confirmed by gastroscopy. Clinicodemographic data were analysed, including symptom onset, endoscopy results, that were assessed for classic features of oesophageal ulceration. Patients were questioned regarding medication intake.

Results

A total of 12 patients were included (mean age, 23.50 ± 3.20 years), eight (66.67%) of whom were female. Based on history of medication and endoscopic findings, these patients were diagnosed with doxycycline-induced oesophageal ulceration. Most patients were found to have taken the medication at bedtime, just before lying down, and/or with insufficient water.

Conclusion

Doxycycline may cause oesophageal irritation when not taken with sufficient water, or taken just before lying down to sleep. Prescribing physicians should be aware of these issues, and instruct patients as to the correct method for intake of doxycycline.

Comparison of a single-dose vectored thermal pulsation procedure with a 3-month course of daily oral doxycycline for moderate-to-severe meibomian gland dysfunction

Purpose

The aim of this study was to compare the efficacy of a single bilateral 12-minute vectored thermal pulsation (VTP) procedure versus daily oral doxycycline for 3 months for moderate-to-severe meibomian gland dysfunction (MGD).

Methods

This prospective, randomized, parallel-group, single-masked study included 28 subjects who received either a single-dose VTP or 3 months of doxycycline treatment. At baseline and 3 months post treatment, all subjects were evaluated for the following: dry eye symptoms with a standard dry eye questionnaire (the Standard Patient Evaluation for Eye Dryness [SPEED]), meibomian gland (MG) function by counting the number of glands yielding liquid secretion with the MG evaluator (MGE), tear breakup time (TBUT) and corneal and conjunctival staining.

Results

In the VTP group, at 3 months, there was a significant improvement in MG function (4.00±1.47 to 7.73±5.53), SPEED score (11.00±3.30 to 5.42±2.15), TBUT (6.26±2.01 to 8.44±1.81), corneal staining (0.38±0.50 to 0.12±0.33) and conjunctival staining (1.69±1.93 to 0.62±0.85). In the doxycycline group, there was a significant improvement in MG function (4.63±1.41 to 10.63±5.91), SPEED score (13.42±4.17 to 9.42±5.47) and conjunctival staining (2.38±1.88 to 1.13±1.51), but the improvement in TBUT (6.90±2.56 to 7.59±2.03) and corneal staining (0.21±0.41 to 0.13±0.34) was not statistically significant (p=0.262 and p=0.414, respectively). At 3 months, SPEED score was significantly better in the VTP group (p<0.05); other parameters were comparable between the two groups.

Conclusion

A single 12-minute bilateral VTP procedure was significantly more effective than the 3-month daily course of oral doxycycline at improving the dry eye symptoms secondary to MGD. A single 12-minute VTP treatment was at least as effective as a dose of doxycycline for 3 months, in improving MG function and all measured signs of MGD. Given the minimal risk profile of the single VTP procedure over long-term doxycycline use, a single VTP presents a favorable alternative to long-term antibiotic use.

Use of a Monte Carlo analysis within a physiologically based pharmacokinetic model to predict doxycycline residue withdrawal time in edible tissues in swine

The pharmacokinetics of doxycycline were studied following a single intravenous (I.V.) and intramuscular (I.M.) injection of 10 mg/kg into eight healthy pigs. The steady-state tissue/plasma partition coefficients were obtained via a 3-h constant rate infusion (CRI) in four pigs. Based on the results of in vivo studies and the parameters derived from published work, a physiologically based pharmacokinetic (PBPK) model was developed to predict the drug concentration in edible tissues. The predicted values were then compared with those derived from a previous study. To account for individual differences in the processes of drug metabolism and/or diffusion, a Monte Carlo (MC) run of 1000 simulations was incorporated into the PBPK model to predict the doxycycline residue withdrawal times in edible tissues in swine. The withdrawal periods were compared with those derived from linear regression analysis. The PBPK model presented here provided accurate predictions of the observed concentrations in all tissues except for the injection site. The withdrawal times in all edible tissues derived from the MC analysis were longer than those from linear regression analysis. Based on the residues in the injection site and muscle tissue, the MC analysis predicted a withdrawal time of 33 days. Here, we illustrate that MC analysis can be incorporated into the PBPK model to accurately predict doxycycline residue withdrawal time in edible tissues in swine.

Safety and efficacy of doxycycline in the treatment of rosacea

Rosacea is a common, chronic, skin condition characterized by recurrent episodes of facial flushing, transient or persistent erythema, papules, pustules, and telangiectasias, in a symmetrical facial distribution. The etiology of rosacea remains unknown and this condition represents a therapeutic challenge because of its chronic nature, progression, potential for disfigurement and psychological impact. Although there is no curative therapy for rosacea, the most widely used systemic agents are oral tetracycline derivatives, including tetracycline, doxycycline, and minocycline. This article reviews the available evidence for the use of doxycycline, a second-generation tetracycline, in the treatment or rosacea.

What is new in esophageal injury (infection, drug-induced, caustic, stricture, perforation)?

PURPOSE OF REVIEW: We will focus separately on infectious, drug-induced and caustic injury of the esophagus and their possible complications such as stricture and perforation. RECENT FINDINGS: There has been a decrease in opportunistic esophageal infection in HIV-positive patients, in particular candidiasis, which remains an important cause of inpatient charges, length of stay and total hospital costs, and new antifungal therapy are currently explored. As far as drug-induced esophageal injury is concerned, more than 1000 cases of all cases due to nearly 100 different medications have been described during the last 10 years. However, the estimated case frequency is probably much higher and the related literature is of low quality, as cases are reported selectively and stimulated by clustering of cases, newly implicated pills or unusual complications. Finally, in the field of caustic ingestion-related injury, there has been greater understanding of geographical differences in prevalence and more frequently involved substances, choice of optimal timing for endoscopy, relationship between symptoms and severity of lesions and appropriate role of steroids and other therapies, such as the topical application of mytomicin C. SUMMARY: This update covers the most relevant papers published on the three areas of interest during the last year.