Clinical evaluation of roxithromycin: a double-blind, placebo-controlled and crossover trial in patients with acne vulgaris

Adverse events in people taking macrolide antibiotics versus placebo for any indication

BACKGROUND

Macrolide antibiotics (macrolides) are among the most commonly prescribed antibiotics worldwide and are used for a wide range of infections. However, macrolides also expose people to the risk of adverse events. The current understanding of adverse events is mostly derived from observational studies, which are subject to bias because it is hard to distinguish events caused by antibiotics from events caused by the diseases being treated. Because adverse events are treatment-specific, rather than disease-specific, it is possible to increase the number of adverse events available for analysis by combining randomised controlled trials (RCTs) of the same treatment across different diseases.

OBJECTIVES

To quantify the incidences of reported adverse events in people taking macrolide antibiotics compared to placebo for any indication.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which includes the Cochrane Acute Respiratory Infections Group Specialised Register (2018, Issue 4); MEDLINE (Ovid, from 1946 to 8 May 2018); Embase (from 2010 to 8 May 2018); CINAHL (from 1981 to 8 May 2018); LILACS (from 1982 to 8 May 2018); and Web of Science (from 1955 to 8 May 2018). We searched clinical trial registries for current and completed trials (9 May 2018) and checked the reference lists of included studies and of previous Cochrane Reviews on macrolides.

SELECTION CRITERIA

We included RCTs that compared a macrolide antibiotic to placebo for any indication. We included trials using any of the four most commonly used macrolide antibiotics: azithromycin, clarithromycin, erythromycin, or roxithromycin. Macrolides could be administered by any route. Concomitant medications were permitted provided they were equally available to both treatment and comparison groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and collected data. We assessed the risk of bias of all included studies and the quality of evidence for each outcome of interest. We analysed specific adverse events, deaths, and subsequent carriage of macrolide-resistant bacteria separately. The study participant was the unit of analysis for each adverse event. Any specific adverse events that occurred in 5% or more of any group were reported. We undertook a meta-analysis when three or more included studies reported a specific adverse event.

MAIN RESULTS

We included 183 studies with a total of 252,886 participants (range 40 to 190,238). The indications for macrolide antibiotics varied greatly, with most studies using macrolides for the treatment or prevention of either acute respiratory tract infections, cardiovascular diseases, chronic respiratory diseases, gastrointestinal conditions, or urogynaecological problems. Most trials were conducted in secondary care settings. Azithromycin and erythromycin were more commonly studied than clarithromycin and roxithromycin.Most studies (89%) reported some adverse events or at least stated that no adverse events were observed.Gastrointestinal adverse events were the most commonly reported type of adverse event. Compared to placebo, macrolides caused more diarrhoea (odds ratio (OR) 1.70, 95% confidence interval (CI) 1.34 to 2.16; low-quality evidence); more abdominal pain (OR 1.66, 95% CI 1.22 to 2.26; low-quality evidence); and more nausea (OR 1.61, 95% CI 1.37 to 1.90; moderate-quality evidence). Vomiting (OR 1.27, 95% CI 1.04 to 1.56; moderate-quality evidence) and gastrointestinal disorders not otherwise specified (NOS) (OR 2.16, 95% CI 1.56 to 3.00; moderate-quality evidence) were also reported more often in participants taking macrolides compared to placebo.The number of additional people (absolute difference in risk) who experienced adverse events from macrolides was: gastrointestinal disorders NOS 85/1000; diarrhoea 72/1000; abdominal pain 62/1000; nausea 47/1000; and vomiting 23/1000.The number needed to treat for an additional harmful outcome (NNTH) ranged from 12 (95% CI 8 to 23) for gastrointestinal disorders NOS to 17 (9 to 47) for abdominal pain; 19 (12 to 33) for diarrhoea; 19 (13 to 30) for nausea; and 45 (22 to 295) for vomiting.There was no clear consistent difference in gastrointestinal adverse events between different types of macrolides or route of administration.Taste disturbances were reported more often by participants taking macrolide antibiotics, although there were wide confidence intervals and moderate heterogeneity (OR 4.95, 95% CI 1.64 to 14.93; I² = 46%; low-quality evidence).Compared with participants taking placebo, those taking macrolides experienced hearing loss more often, however only four studies reported this outcome (OR 1.30, 95% CI 1.00 to 1.70; I² = 0%; low-quality evidence).We did not find any evidence that macrolides caused more cardiac disorders (OR 0.87, 95% CI 0.54 to 1.40; very low-quality evidence); hepatobiliary disorders (OR 1.04, 95% CI 0.27 to 4.09; very low-quality evidence); or changes in liver enzymes (OR 1.56, 95% CI 0.73 to 3.37; very low-quality evidence) compared to placebo.We did not find any evidence that appetite loss, dizziness, headache, respiratory symptoms, blood infections, skin and soft tissue infections, itching, or rashes were reported more often by participants treated with macrolides compared to placebo.Macrolides caused less cough (OR 0.57, 95% CI 0.40 to 0.80; moderate-quality evidence) and fewer respiratory tract infections (OR 0.70, 95% CI 0.62 to 0.80; moderate-quality evidence) compared to placebo, probably because these are not adverse events, but rather characteristics of the indications for the antibiotics. Less fever (OR 0.73, 95% 0.54 to 1.00; moderate-quality evidence) was also reported by participants taking macrolides compared to placebo, although these findings were non-significant.There was no increase in mortality in participants taking macrolides compared with placebo (OR 0.96, 95% 0.87 to 1.06; I² = 11%; low-quality evidence).Only 24 studies (13%) provided useful data on macrolide-resistant bacteria. Macrolide-resistant bacteria were more commonly identified among participants immediately after exposure to the antibiotic. However, differences in resistance thereafter were inconsistent.Pharmaceutical companies supplied the trial medication or funding, or both, for 91 trials.

AUTHORS' CONCLUSIONS

The macrolides as a group clearly increased rates of gastrointestinal adverse events. Most trials made at least some statement about adverse events, such as "none were observed". However, few trials clearly listed adverse events as outcomes, reported on the methods used for eliciting adverse events, or even detailed the numbers of people who experienced adverse events in both the intervention and placebo group. This was especially true for the adverse event of bacterial resistance.

Oral Antibacterial Therapy for Acne Vulgaris: An Evidence-Based Review

BACKGROUND

To some degree, acne vulgaris affects nearly every individual worldwide. Oral antibiotic therapy is routinely prescribed for the treatment of moderate to severe inflammatory acne; however, long-term use of oral antibiotics for acne may have unintended consequences.

OBJECTIVE

The aim of this study was to provide a systematic evaluation of the scientific evidence on the efficacy and appropriate use of oral antibiotics in the treatment of acne.

METHODS

A systematic search of MEDLINE was conducted to identify randomized controlled clinical trials, systematic reviews, and meta-analyses evaluating the efficacy of oral antibiotics for acne. Overall, 41 articles that examined oral antibiotics compared with placebo, another oral therapy, topical therapy, alternate dose, or duration were included in this study.

RESULTS

Tetracyclines, macrolides, and trimethoprim/sulfamethoxazole are effective and safe in the treatment of moderate to severe inflammatory acne. Superior efficacy of one type or class of antibiotic could not be determined, therefore the choice of antibiotic is generally based on the side-effect profile. Although different dosing regimens have been studied, there is a lack of standardized comparator trials to determine optimal dosing and duration of each oral antibiotic used in acne. The combination of oral antibiotics with a topical therapy is superior to oral antibiotics alone.

CONCLUSION

This article provides a systematic evaluation of the scientific evidence of the efficacy of oral antibiotics for acne. Due to heterogeneity in the design of the trials, there is insufficient evidence to support one type, dose, or duration of oral antibiotic over another in terms of efficacy; however, due to increasing resistance to antibiotics, dermatologists should heed consensus guidelines for their appropriate use.

Pharmacotherapy of acne

BACKGROUND

Acne results from the interplay of several pathophysiologic factors, in particular seborrhoea, follicular hyperkeratosis, propionibacteria and inflammation. Recently, it has become clear that inflammatory events are important not only in the course, but also in the initiation of the disease.

OBJECTIVE

The study undertook an evaluation of the effectiveness of currently available pharmacotherapeutic treatment options for acne.

METHODS

After a Medline-based literature search, this article critically reviewed substances used topically (among others, retinoids, antimicrobials, salicylic acid and azelaic acid) and systemically (antibiotics, isotretinoin, hormones and zinc) as well as their combinations with respect to pharmacology, clinical efficacy and side effects.

RESULTS

Modern acne pharmacotherapy provides substances that antagonize one or more of the major pathophysiologic factors of acne. When the clinical picture but also patients' motivation and wishes are appropriately considered, current pharmacotherapy of acne is rational and effective.

Systemic antibiotic therapy of acne vulgaris

BACKGROUND

Inflammatory, medium to severe acne vulgaris is treated with systemic antibiotics worldwide. The rationale is an effect on Propionibacterium acnes as well as the intrinsic anti-inflammatory properties of these antibiotics. Although there are no correlations between the number of P. acnes and the severity of the disease, associations between the degree of humoral and cellular immune responses towards P. acnes and the severity of acne have been reported. Exact data on practical use of these compounds, such as differential efficacy or side effects are unavailable. A summary of currently available studies is presented.

METHODS

The data of studies of systemic antibiotic therapy of acne vulgaris up to 1975, the summary of literature in English up to 1999, a systematic review of minocycline from 2002 as well as the data of randomized controlled studies published and listed in Medline thereafter were reviewed.

RESULTS

Tetracyclines [tetracycline 1,000 mg daily, doxycycline 100 (-200) mg daily, minocycline 100 (-200) mg daily, lymecycline 300 (-600) mg] and erythromycin 1 000 mg daily are significantly more effective than placebo in the systemic treatment of inflammatory acne. The data for tetracycline are best founded. Clindamycin is similarly effective. Co-trimoxazole and trimethoprim are likely to be effective. Clear differences between the tetracyclines or between tetracycline and erythromycin cannot be ascertained. The data for the combination with topical treatments [topical benzoyl peroxide (BPO) or retinoids] suggest synergistic effects. Therefore systemic antibiotics should not be used as monotherapy. In case of similar efficacy, other criteria, such as pharmacokinetics (doxycycline, minocycline, lymecycline have longer half-lives than tetracyclines), the rate of side-effects (tetracycline: side effect-rate approximately 4 % mild side effects; erythromycin: frequent gastrointestinal complaints; minocycline: rare, but potentially severe hypersensitivity reactions; doxycycline: dose-dependent phototoxic reactions), the resistance rate [percentage of resistant bacteria higher with erythromycin (approximately 50 %) than with tetracycline-therapy (approximately 20 %)], and the costs of therapy have to be taken into account.

CONCLUSIONS

The systemic antibiotic therapy of widespread papulo-pustular acne not amenable to a topical therapy is effective and well-tolerated. In general therapy can be carried out for 3 months and should be combined with BPO to prevent resistance.

Acne vulgaris: a review of antibiotic therapy

Antibiotic therapy has been integral to the management of inflammatory acne vulgaris for many years. Systemic antibiotics work via antibacterial, anti-inflammatory and immunomodulatory modes of action, and have been found to be useful in managing moderate-to-severe acne. Commonly prescribed antibiotics include tetracyclines, erythromycin and trimethoprim, with or without sulfamethoxazole. In selecting the appropriate antibiotic for patients needing to receive topical or systemic antibiotic therapy, the clinician should take into account the severity of the acne, cost-effectiveness, the safety profile of the drug and the potential for development of resistance. The widespread and long-term use of antibiotics over the years has unfortunately led to the emergence of resistant bacteria. The global increase in the antibiotic resistance of Propionibacterium acnes may be a significant contributing factor in treatment failures. It is therefore essential that clinicians prescribing antibiotics for the treatment of acne adopt strategies to minimise further development of bacterial resistance. This includes addressing compliance issues, using combination therapies, avoiding prolonged antibiotic treatment, and avoiding concomitant topical and oral antibiotics with chemically dissimilar antibiotics.