India PGx Drug Safety Alerts
Pharmacogenomic variants enriched in Indian populations that require dose adjustment or drug substitution. Based on IndiGen allele frequencies cross-referenced with CPIC Level A/B clinical guidelines.
Why standard dosing fails Indian patients
International drug dosing guidelines are calibrated on European genetic data. South Asian populations carry loss-of-function alleles at markedly different frequencies — CYP2C19*2 (clopidogrel reduced efficacy) is 23% vs 15% globally; G6PD deficiency is 5–15% in malaria-endemic Indian states vs 4% globally. Without population-specific pharmacogenomic context, standard dosing causes measurable harm to 1.4 billion people.
Active alerts
Reduced conversion to active metabolite — up to 40% lower antiplatelet effect
→ Consider Prasugrel or Ticagrelor for Indian patients with ACS
Severely impaired metabolism — 3× higher bleeding risk at standard doses
→ Start at 50% standard dose; use VKORC1 + CYP2C9 genotype-guided dosing
Haemolytic anaemia — life-threatening in G6PD-deficient patients
→ Screen for G6PD deficiency before prescribing. Critical in malaria-endemic states.
Myelosuppression — 3× higher risk of severe toxicity
→ Test TPMT before starting; reduce dose by 50–90% for intermediate metabolisers
Reduced opioid activation — inadequate analgesia in 38% of South Asians
→ Consider alternatives (morphine, oxycodone) or increase dose with monitoring
Impaired hepatic uptake — 4× higher myopathy risk at 80mg dose
→ Limit to 20-40mg or switch to Rosuvastatin/Pravastatin
Reduced glucuronidation — higher SN-38 exposure, neutropenia risk
→ Consider dose reduction for UGT1A1*28 homozygotes before chemotherapy
Data Sources
1,029 Indian genomes — population allele frequencies
Curated drug-gene clinical annotations
Clinical Pharmacogenetics Implementation Consortium Level A/B
10,000-genome Indian population study