Concomitant use of contraceptives and potentially teratogenic medicinal products--results from a study using pharmacy dispensing data in the Netherlands.

The objective of this study was to analyze to what extent potentially teratogenic medicinal products are dispensed concomitantly with contraceptives. Data on dispensed medicinal products in this population-based study were obtained from the Dutch Foundation for Pharmaceutical Statistics. For over 178 potentially teratogenic medicinal products, concomitant use of contraceptives was assessed. The proportion of potentially teratogenic medicinal products dispensed concomitantly with a contraceptive varied significantly from 40.9% (95% CI 40.7-41.2) in 2005 to 43.4% in 2009 (95% CI 44.2-43.7). Significant differences existed as well between age categories with the lowest proportions of concomitant use of contraceptives for any potentially teratogenic drug in women aged 36 through 45 years (35.0%, 95% CI 34.9-35.1) in comparison to those aged 26 through 35 years (47.1%, 95% CI 46.9-47.3) and 15 through 25 years (53.6%, 95% CI 53.4-53.8). Although our data retrieval did not cover the use of nonpharmacological forms of contraception such as condoms and sterilization and as situations may occur during which the use of drugs with (low) teratogenic potential is a balanced decision, our results raise doubts about the safe use of medicinal products with teratogenic potential.