Major
Atorvastatin × Rifampicin
HMG-CoA reductase inhibitors (statins)×Antituberculous antibiotic
Mechanism
Rifampicin strongly induces CYP3A4 and the OATP1B1 transporter – two atorvastatin clearance routes. Atorvastatin plasma levels fall by 80%; lipid-lowering effect weakens.
Symptoms
The patient feels nothing. Laboratory: LDL cholesterol and total cholesterol rise. In high cardiovascular risk patients, myocardial infarction and stroke risk increase.
Management
During anti-TB therapy, switch to pravastatin (less induction-sensitive metabolism) or temporarily stop the statin for a short course. Induction persists for 2 weeks after rifampicin stops.