Ad Hoc Committee report: systemic antibiotics for treatment of acne vulgaris: efficacy and safety

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.

Guidelines for the management of acne vulgaris in adolescents

This article reviews the treatment of acne in adolescents. The choice of therapy should be principally based on the type of lesion and the severity of the acne, but psychosocial disability relating to the disease and the presence of scarring may also influence the approach to treatment.Mild acne generally requires topical treatment only. Benzoyl peroxide, azelaic acid, and antibacterials are generally used for inflammatory lesions. Topical retinoids are particularly effective for noninflamed lesions, and combination therapies are useful for mixed lesions. Moderately severe acne generally requires oral antibacterials. Tetracyclines/oxytetracycline and erythromycin are usually the first-line antibacterials. Second-generation tetracyclines, such as lymecycline, doxycycline, and minocycline, show improved absorption. Minocycline has the advantage of being rarely associated with Propionibacterium acnes antibacterial resistance, but can occasionally lead to potentially serious adverse effects. Trimethoprim is a useful third-line antibacterial therapy for patients resistant to other antibacterial therapies. Benzoyl peroxide should generally be used in combination with oral antibacterials as this has been shown to reduce the development of antibacterial resistance. For severe nodular acne, isotretinoin is the treatment of choice. In addition, over recent years dermatologists have increasingly used this drug to treat patients with moderate acne which has not responded to other systemic therapies, particularly when associated with scarring or significant psychological disability. However, this use is outside the current license of the drug. Isotretinoin is associated with a number of serious adverse effects and careful monitoring of patients during therapy is required.Physical therapies for the treatment of acne nodules and macrocomedones are also important adjuncts to drug therapies.

Propionibacterium acnes-induced IL-8 production may be mediated by NF-kappaB activation in human monocytes

Propionibacterium acnes (P. acnes) causes an inflammatory acne that is characterized by massive neutrophilic infiltration. IL-8 is thought to play an important role in the pathophysiology of P. acnes, although the mechanisms by which P. acnes up-regulates the release of IL-8, a neutrophilic chemokine, from target cells is not well understood. In this study, we investigated the mechanisms through which heat-killed P. acnes induces IL-8 production in THP-1 cells (a human monocytic cell line). We found that P. acnes is able to directly induce IL-8 production and IL-8 mRNA expression in human monocytic cells in a dose- and time-dependent manner through a mechanism requiring transcription factor NF-kappaB activation. Additionally, P. acnes-induced IL-8 secretion was inhibited by roxithromycin, a macrolide antibiotic, and its inhibitory effect seemed to be partially associated with the inhibition of P. acnes-induced NF-kappaB activation. This is the first study to show that NF-kappaB activation is involved in the IL-8 production of monocytic cells stimulated by P. acnes.

Treating acne. A practical guide

Acne is the most common skin disorder affecting adolescents. Although there is no cure for acne, most patients benefit from currently available medications, and most can be managed effectively by the primary care provider. By offering this care, the clinician can reduce the emotional burden of acne and help prevent the permanent scarring commonly seen in the past.

Macrolide antibiotics in paediatric infectious diseases

Erythromycin and other macrolides have enjoyed a renaissance in the 1970s, 1980s and 1990s secondary to the discovery of "new' pathogens such as Chlamydia, Legionella, Campylobacter and Mycoplasma spp. Erythromycin is an important therapeutic agent in the paediatric age group for several reasons: (a) it exhibits proven efficacy for a wide range of infections (upper and lower respiratory tract infections, skin/skin structure infections, prophylaxis of endocarditis/acute rheumatic fever/ophthalmia neonatorum and pre-colonic surgery, campylobacteriosis, chlamydial and ureaplasmal infections, diphtheria, whooping cough, streptococcal pharyngitis) and gastrointestinal (GI) dysmotility states; (b) intravenous formulations are widely available; and (c) it is available in a number of formulations as a generic product, which is likely to result in significant cost savings. Nevertheless, erythromycin and similar earlier macrolides are characterised by a number of drawbacks including a narrow spectrum of antimicrobial activity, unfavourable pharmacokinetic properties and poor GI tolerability. Newer macrolides such as clarithromycin and azithromycin are useful in serving the needs of paediatric patients who are erythromycin-intolerant or who have infections caused by organisms that are intrinsically erythromycin-resistant, or for which a high percentage of strains are resistant (e.g. Haemophilus influenzae, Helicobacter pylori, Mycobacterium avium complex). In addition, these newer macrolides may be considered as alternatives to oral amoxicillin-clavulanic acid, second or third generation cephalosporins, or erythromycin plus sulphonamide in this patient population. Selection between specific macrolides and between macrolides and other antibiotics in the paediatric population is likely to depend, at least for the immediate future, on separate comparisons of product availability, cost, effectiveness and tolerability profiles.

Topical erythromycin and zinc therapy for acne

A double-blind, 12-week study was undertaken to determine the safety and efficacy of a formulation of 4% erythromycin plus 1.2% zinc acetate compared with its vehicle. The study was continued for 40 weeks after the 12-week double-blind phase by switching vehicle-treated patients to active treatment and continuing to give patients treated with active drug the same treatment. Seventy-three female patients started the study; 39 completed 1 full year of study. In the first 12 weeks statistically significant differences were noted in the efficacy of the erythromycin-zinc compared with vehicle for acne severity grades (global assessment) and for papule, pustule, and comedo counts. After crossover, the vehicle-treated group receiving active therapy duplicated the improvement of the group initially treated with erythromycin-zinc. No clinical problems with superinfection or secondary infection occurred during 1 year of treatment in 39 patients.

Recalcitrant acne vulgaris. Clinical, biochemical and microbiological investigation of patients not responding to antibiotic treatment

A small, but clinically significant proportion of acne patients fail to respond adequately to antibiotic therapy. All non-responding acne patients attending the Leeds General Infirmary between September 1985 and April 1986 (49 out of a total of 610 patients; 8%) were investigated with respect to changes in their acne grade, microbial flora and sebum excretion rate. They were compared with 22 age and sex matched untreated control subjects. It was found that in 65% of non-responding patients there was no microbiological abnormality, in 16% there was evidence of Gram-negative folliculitis and 20% carried predominantly antibiotic resistant propionibacteria compared with only 5% of untreated controls. There was a significant association between erythromycin therapy and the isolation of erythromycin resistant propionibacteria (P less than 0.001). A causal link, however, has yet to be established between carriage of antibiotic resistant propionibacteria and failure to respond to antibiotic therapy. Our results show that for most patients with recalcitrant acne a non-microbiological explanation must be sought for the lack of therapeutic success. The mean sebum excretion rate (SER) of the non-responding patients was significantly higher than that of matched untreated acne patients (P less than 0.001). A majority of non-responders (69%) had an SER above the upper 95% confidence limit of the control mean. The SER may affect treatment efficacy by influencing the antibiotic concentration within the pilosebaceous ducts.

Comparative efficacy of oral erythromycin versus oral tetracycline in the treatment of acne vulgaris. A double-blind study

The efficacy of erythromycin base (E-Mycin tablets, 333 mg) and the efficacy of tetracycline hydrochloride (Panmycin tablets) were compared in this double-blind, randomized study. Two hundred patients with moderate to moderately severe acne vulgaris were randomly assigned to the study. One hundred patients received 1 gm of erythromycin base by mouth per day for 4 weeks, followed by 333 mg/day for 8 weeks, plus placebo for tetracycline. The second group of patients received 1 gm of tetracycline by mouth per day for 4 weeks, followed by 500 mg/day for 8 weeks, plus placebo for erythromycin. Both drugs reduced acne severity to the same extent. Pustules, papules, and open comedo counts decreased significantly over the 12-week period. Seventy-seven percent of the erythromycin-treated patients and 89% of the tetracycline-treated patients stated that their acne was markedly improved or improved by week 12. Most of the side effects in patients treated with erythromycin were gastrointestinal symptoms. Among the side effects in patients treated with tetracycline were Candida vaginitis in one patient and pseudotumor cerebri in one patient.

A double-blind study of the effectiveness of a 3% erythromycin and 5% benzoyl peroxide combination in the treatment of acne vulgaris

One hundred sixty-five subjects completed a 10-week, double-blind controlled study comparing the following: (1) a combination of 3% erythromycin and 5% benzoyl peroxide in a gel, (2) 5% benzoyl peroxide gel, (3) 3% erythromycin gel, and (4) the gel vehicle. The benzoyl peroxide gel and the erythromycin gel were superior to the control gel; however, the combination product was more effective than any of the others. This was true for both pustular and papular lesions, but the most dramatic effect was on combined inflammatory lesions, i.e., papules and pustules.

Topical tetracycline hydrochloride vs. topical clindamycin phosphate in the treatment of acne: a comparative study

In a comparative study of topical antibiotic solutions, clindamycin phosphate vs. tetracycline hydrochloride for the treatment of mild t moderate inflammatory facial acne, clindamycin phosphate solution proved to be a superior agent in the reduction of papules and pustules. Both preparations had minimal side effects.

Acne treated with a tropical tetracycline preparation: results of a one-year multi-group study

One hundred five patients were treated effectively with topically applied tetracycline in an ethanol-water solution with n-decyl methyl sulfoxide, and observed for a year. Comedones and cystic lesions were least responsive to topical tetracycline. Side effects, which were minor, included yellow staining of facial skin and stinging after application. Two patients, one with juvenile diabetes and one with congenital nephritis, successfully used the preparation without adverse effects.