Integrating Pharmacokinetic, Pharmacogenomic, and Clinical Risk Data to Individualise Hormonal Contraception and Minimise Thrombotic Risk: A Translational Framework.

Individualizing hormonal contraception requires integrating clinical risk with drug exposure determinants. We performed a comprehensive narrative evidence synthesis combining epidemiology, mechanistic coagulation studies, physiologically‑based pharmacokinetic (PBPK) modelling, drug–drug interaction (DDI) literature and pharmacogenetic reports to clarify how pharmacokinetic and genetic factors alter contraceptive hormone exposure and influence thrombotic risk. Epidemiologic data confirm increased venous thromboembolism (VTE) risk with combined oestrogen–progestin methods and minimal baseline risk with progestin‑only or non‑hormonal methods; inherited thrombophilias amplify absolute risk. PBPK studies and clinical DDI reports demonstrate that strong CYP3A4 inducers (e.g., rifampicin, certain antiepileptics) substantially reduce systemic steroid exposure – effects variably mitigated by route (intrauterine and depot methods less affected than oral or transdermal). Pharmacogenetic evidence, though limited, indicates clinically meaningful variability in exposure for steroid substrates of CYP3A isoforms and transporters (notably variant CYP3A5 expression influencing implant exposure in some populations). Synthesizing these domains, we propose a translational framework to: (1) quantify exposure-modifying DDIs using PBPK-informed heuristics, (2) prioritize routes/methods least impacted by metabolism or adherence concerns, and (3) target thrombophilia/genotype testing where results would change management. We discuss gaps limiting quantitative risk prediction (heterogeneous genotype data, sparse prospective outcome studies) and propose research priorities, including prospective PBPK–epidemiology linkages and pharmacogenetic validation. This synthesis aims to equip clinicians and clinical pharmacologists with a practical, mechanistically grounded approach to safer, personalized contraceptive selection.