Hormonal contraceptive use in Ireland: trends and co-prescribing practices

Abstract

Hormonal contraceptives are highly prevalent. Currently, little is known about Irish hormonal contraceptive trends to date since the 1995 British media contraceptive controversy. The aim of this study was to examine recent trends in contraceptive use in Ireland and to determine the frequency of co-prescriptions with important interacting medications. Approximately 40% of the Irish population are prescribed 70% of total medicines under the Irish GMS scheme. Medicines were identified using the WHO Anatomical Therapeutic Chemical (ATC) classification system. Regression analysis was used to examine trends over time. Of all contraceptives dispensed in 2013, oral contraceptives were used the most (74%) and long acting reversible contraceptives (LARCs) the least (7.5%). Fourth generation combined oral contraceptives (COCs) predominated, although a slight significant decline was shown (P < 0.0001). Second and third generation COCs were significantly increasing and decreasing, respectively (P < 0.0001). Progestin-only pills were significantly increasing (P < 0.0001 across age groups). Low rates of contraceptive co-prescribing with important interacting drugs are shown. However, 93.6% of those on enzyme-inducing anti-epileptic medications were co-prescribed ineffective contraception containing <50 μg oestrogen.Irish prescribing trends of second and third generation COCs have remained consistent since 1995. The slow decline in fourth generation COC uptake follows new evidence of an increased risk of venous thromboembolism (VTE) reported in 2011. The low, but increasing, uptake of LARCs is consistent with other countries. Co-prescribing practices involving hormonal contraceptives requires continued vigilance. This study emphasizes the need to optimize co-prescribing practices involving hormonal contraceptives and anti-epileptic medications and highlights the need to address the barriers to the currently low uptake of LARC methods in Ireland.

Keywords: antiepileptic medications; co-prescribing trends; combined oral contraceptives (COCs); drug interactions; long acting reversible contraceptives (LARCs).