Prescriptive contraceptive use among isotretinoin users in the Netherlands in comparison with non-users: A drug utilisation study
Purpose: To assess the compliance with the isotretinoin Pregnancy Prevention Programme (PPP) by evaluating the use of prescribed contraceptives among isotretinoin users. The PPP contains a requirement for the use of contraceptive methods for women of childbearing potential. Methods: A drug utilisation study was performed using data from a drug prescription database (containing Dutch community pharmacy data) covering a population of 500000 patients. Contraceptive use in female isotretinoin users and in a reference group of female non-isotretinoin users (aged 15-49years) was compared using data from 1999 until 2006 in 2-year periods. Descriptive statistics were used. Results: Of the female isotretinoin users (n=651), 52%-54% filled prescriptions on contraceptives in strict accordance to the PPP, used before, during, and after discontinuation of isotretinoin, compared with 39%-46% in the reference group. A more liberal approach of a minimum of one prescription for a contraceptive method showed 61%-64% use of contraceptives among isotretinoin users. Similar patterns were seen when data were broken down in age groups. Furthermore, a higher proportion of female patients using isotretinoin prescribed by general practitioners used prescribed contraceptives compared with those receiving isotretinoin by specialists. Conclusion: Compliance with the contraceptive use according to a PPP for a teratogenic drug such as isotretinoin is 52%-64%, which is lower than anticipated. Reasons for the low compliance will need to be clarified before further measures can be taken.