MAJOR — Use With Caution
FDA-documented interaction. Chronic rifampin reduces simvastatin exposure by up to 87%. Statin therapy may be ineffective during rifampin treatment.
Evidence level: STRONG
Rifampin dramatically reduces simvastatin effectiveness by speeding up its breakdown. Your cholesterol medication may essentially stop working while you take rifampin.
Rifampin is a potent inducer of CYP3A4 and P-gp. During co-administration, it dramatically reduces simvastatin levels (up to 87% reduction). Paradoxically, a single dose of rifampin can INHIBIT OATP1B1, transiently increasing statin levels. FDA statin labels warn about rifampin.
Your statin may not work during rifampin treatment. Discuss with your doctor whether to increase the statin dose, switch to a less-affected statin (pravastatin, rosuvastatin), or accept temporarily less cholesterol control.
Some antibiotics (erythromycin, clarithromycin) strongly inhibit CYP3A4 and can dramatically increase statin levels, raising rhabdomyolysis risk. Take Simvastatin in the evening as usual. Your prescriber may temporarily pause or reduce the statin during short antibiotic courses.
Cardiovascular disease, concurrent inducers
No acute symptoms — the danger is loss of cholesterol control, which increases long-term cardiovascular risk
Discuss alternative statins less affected by CYP3A4 induction (pravastatin, rosuvastatin). Accept that cholesterol control may be suboptimal during TB treatment.
Statin interactions often involve liver enzyme competition. Ask your doctor about alternative statins (rosuvastatin and pravastatin have fewer CYP interactions) or spacing doses 12 hours apart. CoQ10 supplementation may help with statin-related muscle discomfort.
Rifampin dramatically reduces simvastatin effectiveness by speeding up its breakdown. Your cholesterol medication may essentially stop working while you take rifampin.
Some antibiotics (erythromycin, clarithromycin) strongly inhibit CYP3A4 and can dramatically increase statin levels, raising rhabdomyolysis risk. Take Simvastatin in the evening as usual. Your prescriber may temporarily pause or reduce the statin during short antibiotic courses.
No acute symptoms — the danger is loss of cholesterol control, which increases long-term cardiovascular risk
Statin interactions often involve liver enzyme competition. Ask your doctor about alternative statins (rosuvastatin and pravastatin have fewer CYP interactions) or spacing doses 12 hours apart. CoQ10 supplementation may help with statin-related muscle discomfort.
Discuss alternative statins less affected by CYP3A4 induction (pravastatin, rosuvastatin). Accept that cholesterol control may be suboptimal during TB treatment.
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