When do you recommend HLA testing prior to prescribing lamotrigine, carbamazepine, or oxcarbazepine to patients of Asian descent?  

I never use carbamazepine given how it’s a pan inducer and often lowers the level of other medications that may be in the regimen, such as quetiapine and haloperidol, since they are mainly metabolized by CYP3A4. Oxcarbazepine has a 50% reduction in the induction of carbamazepine, so I use tha...

This is one of the few actionable tests to avoid the more frequent occurrence of DRESS (Drug Rash with Eosinophilia Syndrome) or SJS (Stevens-Johnson Syndrome). Practically speaking, it is unusual for clinicians to have these HLA tests available in a fashion timely enough to match the usual need for...