Actionable Pharmacogenomics and Essential Medicines: An Analysis of WHO and African Lists for Safer and Efficacious...

The World Health Organization Model Essential Medicines List and African national essential medicines lists (EMLs) detail drugs intended to be consistently available within national health systems, thereby supporting clinicians and pharmacists in making evidence-based treatment decisions. At present, these EMLs do not account for pharmacogenomics, despite known drug-gene interactions and the considerable genetic diversity found throughout Africa. In the absence of pharmacogenomic considerations, the medicines lead to sub-optimal treatment outcomes, especially across a continent such as Africa which represents more genetic variation that the rest of the world combined. Herein, we review EMLs from the WHO, and from 52 African countries, highlighting systemic medicines for which actionable pharmacogenomic-biomarker testing recommendations exist. Furthermore, we assess the feasibility of PGx-guided dosing in eight African countries by examining the availability of registered drug formulations that facilitate dose adjustment. The 2023 WHO EML comprised 447 unique systemic medicines, with 58 (13%) categorized as medicines with actionable pharmacogenomic biomarkers. African country EMLs collectively featured 774 such medicines, with an average of 294 per country (range: 125-465). On average, for each country one in every eight medicines in the Essential Medicines List was associated with established pharmacogenomic guidance. PGx recommendation. Cumulatively in African EMLS the most frequent drug classes with this designation are anti-infectives (25.6%), immunomodulators/antineoplastics (16.7%), and medicines for mental and behavioral disorders (14.1%). Analysis of eight African countries determined that implementability ranged from 75% to 96% based on product formulation and strength availability to enable drug or dose modification. We provide data that contributes towards a foundation of increasing evidence showing that integrating pharmacogenomic knowledge into the selection processes for essential medicines and ensuring the availability of appropriate drug formulations can enhance treatment safety and efficacy across Africa.