Isotretinoin use and compliance with the Dutch Pregnancy Prevention Programme: a retrospective cohort study in females of reproductive age using pharmacy dispensing data

Abstract

Background: Isotretinoin is very effective in the treatment of severe acne. However, because of the teratogenic properties of this agent an isotretinoin Pregnancy Prevention Programme (PPP) was implemented in the Netherlands to guarantee that treatment is contraindicated in women of reproductive age unless at least one effective method of contraception is used. Furthermore, the PPP stipulates that isotretinoin treatment should be managed by physicians or specialists experienced in treatment with this drug and that only monthly prescriptions are issued.

Objective: To assess compliance with the Dutch isotretinoin PPP in women of reproductive age during the study period of 1 January 2005 to 31 December 2008.

Methods: Detailed information on dispensed medication and co-medication was available from the Dutch Foundation of Pharmaceutical Statistics. Four types of outcome were studied: concomitant dispensing of hormonal contraceptive with isotretinoin; the proportion of specialist prescribing of isotretinoin; prescribing of conventional acne therapy prior to isotretinoin initiation; and isotretinoin dispensing exceeding the maximum amount. The use of contraceptives in women aged between 15 and 45 years was defined as concomitant if the period of systemic contraceptive use overlapped the period of isotretinoin dispensing for at least 10 days, or if any dispensing of an intrauterine or intravaginal contraceptive was recorded since the year 2000. Dispensings were separated into those prescribed by either specialists or general practitioners (GPs). The use of antibacterials, antiandrogens or topical agents against acne was checked 4 months prior to an isotretinoin dispensing, and a possible excess of the maximum amount of isotretinoin was defined as prescriptions of more than 100 defined daily doses.

Results: During the study period, data were available for 442 Dutch pharmacies encompassing 4881 women of reproductive age using isotretinoin at least once during study period. Among women of reproductive age, the use of isotretinoin increased during the study period. The proportion of isotretinoin initiation with concomitant oral hormonal or intrauterine contraceptives was low (59.3% [95% CI 57.6, 61.0]). Initiation of isotretinoin by a specialist increased the chance for concomitant contraception by 26% (95% CI 6.0, 49.0); in 78.2% (95% CI 76.8, 79.6) of women, isotretinoin was initiated by a specialist. Conventional acne therapy up to 16 months prior to isotretinoin initiation was found in 70% of the women (70.3% [95% CI 66.0, 74.6]). In 1.4% (95% CI 1.0, 1.8) of cases of treatment initiation, the amount of isotretinoin dispensed on one prescription seemed too high.

Conclusion: Attention should be paid to improving the implementation of the isotretinoin PPP. Despite clear guidelines and warnings in the product information, our study strongly suggests that concomitant use of isotretinoin and contraceptives is too low. Even though we will have missed non-pharmacological forms of contraception, these results raise doubts about the safe use of isotretinoin in women of reproductive age in the Netherlands. Furthermore, isotretinoin does not seem to be used in cases of severe acne only. Reserving isotretinoin prescribing to specialists may improve adherence to the PPP.