Topical tretinoin (Retin A)
Most published studies on topical tretinoin (Retin A) focus on the side effect of minor skin irritation. A multicenter, double-blind parallel study10 compared the safety and efficacy of 2 formulations of tretinoin gel formulations. Adverse dermatologic side effects commonly reported are in Table 1. These cutaneous irritant side effects, while noted in up to 50% of treated patients, peaked in 7 days and decreased significantly over time.
Topical tretinoin has been in clinical use for more than 25 years. Topical delivery results in a very low systemic exposure; plasma retinoid levels measured after topical use remain at or below endogenous levels, likely due to very limited absorption.11 Topical tretinoin is not associated with an increased risk for major congenital disorders. A retrospective study of 215 women on tretinoin during the first trimester compared with 430 controls found that the relative risk for a major congenital anomaly was 0.7 (95% CI, 0.2–2.3). The authors concluded that topical tretinoin did not increase congenital anomaly risk.12
Recommendations from others
No clinical guidelines have been published about the long-term use of tetracycline or topical tretinoin. An ad hoc committee of the American Academy of Dermatology concluded “tetracycline is a rational, effective, and relatively safe drug for use in the treatment of acne vulgaris when given in a dosage of 1 gm or less per day for long term therapy.”7 Other experts, more concerned with growing antibiotic resistance, recommend steps to help prevent increasing resistance (Table 2).
TABLE 2
Treatment recommendations to reduce antimicrobial resistance
| Do not prescribe systemic antibiotics if a topical medication will suffice |
| Avoid concomitant topical and systemic use of different antibiotics |
| Antibiotic therapy should continue for no longer than necessary, with a maximum period of 6 months |
| Do not “switch” or “rotate” antibiotics in patients who are not responding to therapy |
| Try systemic retinoids if acne fails to respond within 6 months of antibiotic therapy or quickly relapses |
| Adapted from Cooper et al.2 |
CLINICAL COMMENTARY
Use a judicious approach to topical agents and systemic antibiotics
Marsha Mertens, MD
Mercy Family Medicine Residency, St. Louis, Mo
We should use a judicious approach with appropriate use of topical agents to treat acne. In those cases where acne is not responding, systemic antibiotics can be quite effective and very well tolerated. Regarding antimicrobial resistance of P acnes, we should avoid changing antibiotics unnecessarily, and taper to the lowest effective dose once the acne is well controlled. I think the dictum to avoid treating with systemic antibiotics for longer than 6 months is not widely followed. Often, much longer courses of treatment are necessary. For an individual patient, the risk of developing resistant P acnes is often preferable to the alternatives of inadequate acne control or systemic isotretinoin. Periodic attempts should be made to discontinue antibiotics when acne is well controlled, with resumption of the same antibiotic if one continues to be needed.