Examples of pharmacogenetic susceptibility for drug-specific adverse drug reactions.
| Drug/drug class | Pharmacogenetic marker | Additional susceptibility factors | Example of clinical context |
|---|---|---|---|
| Carbamazepine | HLA B*15:02 (in the populations listed) | Han-Chinese, Thai and Malaysian populations | Marker for carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis |
| Simvastatin | SLCO1B1 (solute carrier organic anion transporter 1B1) | Advanced age, untreated hypothyroidism, excess physical activity, concomitant medications (eg fibrates) | Statin-induced rhabdomyolysis (rare) whose risk is four times greater with single defective allele, 16 times greater with two defective alleles |
| Abacavir | HLA-B*57:01 | Higher CD8 cell count at start of therapy | Marker for abacavir-induced hypersensitivity reactions with fever, rash, lethargy and abdominal and acute respiratory symptoms |
| Thiopurines (Azathioprine and mercaptopurine) | TPMT activity | N/A | 1 in 10 individuals are heterozygous (50% normal TPMT activity) and 1 in 300 have completely deficient activity. Thiopurine-induced myelosuppression is associated with TPMT activity. |
N/A = not applicable; TPMT = thiopurine methyl transferase