An Open Label, Multi-Center, Non-Interventional Post-Marketing Surveillance to Monitor the Safety and Efficacy of ALTARGO® (Retapamulin) Administered in Korean Patients According to the Prescribing Information

Retapamulin: Current Status and Future Perspectives

: Retapamulin is one of the antibiotics recently developed semi-synthetically to inhibit protein synthesis in a specific manner different from other antibiotics. This pleuromutilin derivative shows magnificent anti-bacterial activity in Gram-positive pathogens, especially Staphylococcus aureus and Streptococcus pyogenes, and now it is available in ointment formulations (1%) for clinical use with negligible side effects. Despite the low potential for resistance development, antimicrobial susceptibility rates are significantly high. This is especially important when the prevalence of mupirocin-resistant strains is increasing, and the need for new alternatives is urgent. Unfortunately, due to its oxidation by cytochrome p450, this drug cannot be used systemically. However, another pleuromutilin derivative with systemic use, lefamulin, was approved in August 2019 by the US Food and Drug Administration. In addition to pharmacokinetic features, financial issues are also barriers to consider in the progress of new antimicrobials. In this review, we attempt to take a brief look at the derivatives usable in humans and explore their structures, action mode, metabolism, possible ways of resistance, resistance rates, and their clinical use to explain and highlight the valuable points of these antibiotics.

Emerging Treatment Strategies for Impetigo in Endemic and Nonendemic Settings: A Systematic Review

PURPOSE

Impetigo affects approximately 162 million children worldwide at any given time. Lack of consensus on the most effective treatment strategy for impetigo and increasing antibiotic resistance continue to drive research into newer and alternative treatment options. We conducted a systematic review to assess the effectiveness of new treatments for impetigo in endemic and nonendemic settings.

METHODS

We searched PubMed, MEDLINE, CINAHL, Web of Science, and Embase via Scopus for studies that explored treatments for bullous, nonbullous, primary, and secondary impetigo published between August 1, 2011, and February 29, 2020. We also searched online trial registries and hand-searched the reference lists of the included studies. We used the revised Cochrane risk of bias (version 2.0) tool for randomized trials and the National Heart, Lung, and Blood Institute for nonrandomized uncontrolled studies to assess the risk of bias.

FINDINGS

We included 10 studies that involved 6651 participants and reported on 9 treatments in the final analysis. Most clinical trials targeted nonbullous impetigo or did not specify this. The risk of bias varied among the studies. In nonendemic settings, ozenoxacin 1% cream appeared to have the strongest evidence base compared with retapamulin and a new minocycline formulation. In endemic settings, oral co-trimoxazole and benzathine benzylpenicillin G injection were equally effective in the treatment of severe impetigo. Mass drug administration intervention emerged as a promising public health strategy to reduce the prevalence of impetigo in endemic settings.

IMPLICATIONS

This review highlights the limited research into new drugs used for the treatment of impetigo in endemic and nonendemic settings. Limited recent evidence supports the use of topical ozenoxacin or retapamulin for impetigo treatment in nonendemic settings, whereas systemic antibiotics and the mass drug administration strategy have evidence for use in endemic settings. Given the troubling increase in resistance to existing treatments, there is a clear need to ensure the judicious use of antibiotics and to develop new treatments and alternative strategies; this is particularly important in endemic settings. PROSPERO identifier: CRD42020173042.

Occupational inhalation poisoning with the veterinary antibiotic tiamulin

Introduction: Tiamulin is a semisynthetic pleuromutilin diterpene veterinary antibiotic, widely used in farms. We present a case of prolonged QT-interval and ventricular tachyarrhythmia after tiamulin inhalation.Case presentation: A 43-year-old veterinarian without previous medical history was dividing granulated powder of antibiotic gravimetrically without wearing personal protective equipment. Half an hour after exposure, nausea occurred; four hours later he started to vomit and soon after that he experienced syncope. He was unconscious three minutes; afterwards he became somnolent, dizzy and nauseated with sweating and salivation. On admission to hospital five hours after exposure, he was conscious and had heart rate 70 beats/min and blood pressure 140/80 mmHg. Initial laboratory results were normal. Electrocardiography showed a prolonged QTc-interval of 730 ms with numerous polymorphic ventricular extrasystoles and episodes of non-sustained polymorphic ventricular tachycardia that resolved after treatment with lidocaine and magnesium. Subsequent electrocardiography revealed gradual shortening of QTc-interval with QTc-interval normalization (430 ms) between 24 and 32 hours after tiamulin exposure. Laboratory tests, morphologic heart diagnostics and genetic testing excluded other potential causes of QTc-interval prolongation. Subsequent toxicology analysis by LC-MS/MS confirmed tiamulin in his serum samples on admittance (500 ng/mL).Conclusion: Tiamulin inhalation can be associated with prolonged QT-interval and ventricular tachyarrhythmia. QT-interval prolongation could be expected in overdoses of emerging human pleuromutilins.