Inconsistent reporting of drug-drug interactions for hormonal contraception and antiepileptic drugs - Implications for reproductive health for women with epilepsy.

Drug compendia are the source of safety prescribing information. We assessed the reporting concordance of drug-drug interactions between hormonal contraception and antiepileptic drugs (AEDs) among eight leading international drug compendia. Antiepileptic drugs reported to interact with ≥1 form of hormonal contraception were reviewed. Scaled concordance was quantified using linearly weighted percent agreement (wPA). Differences in interaction severity rankings between hormonal contraception forms were evaluated using the Wilcoxon signed-rank test. There was high agreement among compendia for interactions of combined hormonal contraception interactions with AEDs (wPA = 0.82-0.84), especially potent enzyme-inducing AEDs (wPA = 0.89). However, concordance was reduced for AED interactions with progestin-only contraception (wPA = 0.69-0.81). Extreme interaction reporting discrepancies were found for less potent enzyme-inducing AEDs. The greatest variability in interaction reporting was observed for injectable and intrauterine contraception (wPA = 0.69 and 0.70, respectively), which are the only hormonal contraception options currently classified as not interacting with enzyme-inducing AEDs. Drug-drug interaction reporting variability can have major clinical implications and highlights critical knowledge gaps in the care of women with epilepsy of childbearing age. Further research on AED-contraceptive interactions is needed to standardize compendia reporting and enhance evidence-based clinical guidelines for women with epilepsy.