Table 1:

Major lessons learned from studies of single drug pharmacogenetic outcomes

Drug	Major lessons learned
Warfarin	• Define multiple genetic pathways and specific variants modulating drug action prior to mounting trials • Include multiple ancestries • Specific endpoints chosen (e.g. efficacy versus adverse events) determine ability to detect an effect
Abacavir, carbamazepine	• Pre-clinical data may align with RCT outcomes • Endpoints should be defined as precisely as possible • Practitioner education is critical to successful implementation • Include multiple ancestries
Clopidogrel	• Include multiple ancestries • Variant allele frequency determine the likelihood of defining a pharmacogenetic outcome effect
Azathioprine	• A potentially beneficial outcome of pharmacogenetic testing is confined to patients with variant alleles • Equipoise can change as genotypes become available and used