The Effect of Antibiotics on the Efficacy of Oral Contraceptives, Tanning Bed Use, Sunbathing, and Sunscreen Use, and Tacrolimus Ointment is Safe and Effective in the Treatment of Atopic Dermatitis

This online-only bonus feature is an ongoing review of past peer reveiw journal articles with significant impact on dermatology.

Sean McGregor, DO, PharmD

The Effect of Antibiotics on the Efficacy of Oral Contraceptives: A [Myth] Revisited

In this months blog, we continue our review of Alan Fleischer’s most memorable and favorite articles. In 1989, Fleischer and Resnick published a review on the effect of antibiotics and the efficacy of oral contraceptives. Antibiotics have been an important component of acne treatment regimens for many years. Historically, there were concerns regarding the reduced efficacy of oral contraceptives with concomitant antibiotic use. In fact, in 1989, the Physician’s Desk Reference stated that, “oral contraceptives may be rendered less effective.” The proposed mechanisms for this interaction were increased excretion of oral contraceptives, decreased enterohepatic circulation, and increased degradation via liver enzymes. Indeed, reductions in enterohepatic circulation were seen in animal studies, but further studies in women revealed no significant changes in either oral contraceptive or hormonal levels. The expected rate of pregnancy at that time was approximately 1 pregnancy per 100 woman-years in women taking oral contraceptives. In order to prove a clinically significant drug interaction, a study of thousands to tens of thousands of women would have to be performed in order to account for the low risk of pregnancy. Additionally, adherence and other psychosocial factors contribute to the rates of unintended pregnancy. Fleischer and Resnick ultimately recommended, “that antibiotic drugs can be sensibly and safely prescribed to women using oral contraceptives,” as long as they understood the possibility of a remote interaction. In 2002, Archer and Archer, after a review of the pharmacokinetic and clinical data on oral contraceptive and antibiotic use, concluded that there was no evidence to support the hypothesis, except in cases of rifampin use. Additionally, according to the CDC, there has been no significant change in the percentage of unintended pregnancy since 1982.

Fleischer A and Resnick S. The Effect of Antibiotics on the Efficacy of Oral Contraceptives: A Controversy Revisited. Arch Dermatol. 1989;125:1562-1564.

Archer JS and Archer DF. Oral Contraceptive Efficacy and Antibiotic Interaction: A Myth Debunked. J Am Acad Dermatol. 2002;46(6):917-23.

Mosher WD, Jones J, and Abma JC. Intended and Unintended Births in the United States: 1982-2010. National Health Statistics Reports. 2012;55:1-27.

 

A Survey of Attitudes, Beliefs, and Behavior Regarding Tanning Bed Use, Sunbathing, and Sunscreen Use

We will now take a look at the historical attitudes, beliefs, and behaviors of patients regarding sunlight exposure. In 1993, Mawn and Fleischer reported the results of a questionnaire distributed to 447 white persons in a shopping mall in Brevard, North Carolina, a large social function, and a cruise ship. Respondents were asked whether early skin aging, wrinkling, or skin cancer were induced by sunlight exposure. The patient’s skin type, use of a tanning bed, and sunbathing habits were also addressed. A total of 176 men and 300 women ranging in age from 16 to 90 years of age were included in the study. A total of 42% of respondents seldom or never used sunscreen following 1 hour of sunlight exposure. Seven percent of respondents with either skin type I or II sunbathed at least once per week. Tanning bed users accounted of 34% of respondents and vacation preparation (51%) and darker skin tone (35%) were the most common reasons for use. Additionally, women, more than men, used tanning beds (45% vs 14%). Among tanning bed users, 18% felt 1 hour in the sun hurt their skin and 13% reported that tanning beds were worse than the sun. Overall, 95% of respondents identified that skin cancer was associated with long-term sunlight exposure. Despite this fact, 10% of tanning bed users would continue to use tanning beds if they proved to cause skin cancer. Respondents reported a relaxed feeling (58%) and self confidence (20%) as benefits of tanning bed use.

Mawn VB and Fleischer A. A Survey of Attitudes, Beliefs, and Behavior Regarding Tanning Bed Use, Sunbathing, and Sunscreen Use. J Am Acad Dermatol. 1993;29:959-62.

 

Tacrolimus Ointment is Safe and Effective in the Treatment of Atopic Dermatitis: Results in 8000 Patients

We conclude with a review of one study on topical tacrolimus. Tacrolimus (Protopic) ointment is a topical calcineurin inhibitor used in the treatment of atopic dermatitis (AD). The primary objective of this study was to evaluate the efficacy and safety of tacrolimus 0.1% and 0.03% ointment twice daily for the treatment of atopic dermatitis. This was an open label study that included both adult and pediatric patients > 2 years of age. Patients were not allowed to use other medications during the study but were allowed to use emollients. A total of 7,923 patients were included in the study and 50% of those patients were children as defined by an age < 15 years old. Approximately 96% of patients had moderate to severe AD and 72% of patients were white. The majority of patients received tacrolimus 0.1% ointment (92.7%) and the mean percentage of body surface area (BSA) affected was 33.2%. Additionally, 76% of patients had head and neck involvement. The primary efficacy endpoint was the mean reduction in %BSA affected. At 1, 12, and 18 months, the mean %BSA was reduced by 52%, 71%, and 91%, respectively. Despite being a protocol violation, some patients received topical steroids during the study. However, this occurred in < 4% of patients. Adverse events accounted for 6.1% of discontinuations from the study and the most common reasons were pruritus and skin burning. Pruritus and skin burning occurred in 20.4% and 22.6% of patients, respectively, and were significantly associated with increased disease severity. No evidence of skin atrophy was observed throughout the trial.

Koo J, Fleischer A, Abramovits W, et al. Tacrolimus Ointment is Safe and Effective in the Treatment of Atopic Dermatitis: Results in 8000 Patients. J Am Acad Dermatol. 2005;53:S195-205.