Drug interactions
Rifapentine + Simvastatin
Severity: Moderate
Rifapentine and Simvastatin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Rifapentine is a CYP3A4 inducer and can substantially lower simvastatin and active metabolite exposure, reducing cholesterol-lowering efficacy. Enzyme induction persists for some time after rifapentine is stopped. The concern is loss of effect, not toxicity.
What this interaction means in plain words
Rifapentine and Simvastatin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Rifapentine belongs to Anti Bacterial; Simvastatin belongs to Cardiovascular.
Why it happens
Rifapentine induces CYP3A4, increasing first-pass and systemic clearance of simvastatin.
What to do
Monitor LDL cholesterol and consider a higher statin dose or a non-CYP3A4 statin such as pravastatin or rosuvastatin during therapy. Reassess the dose after rifapentine is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Simvastatin
- Atazanavir + Simvastatin Contraindicated
- Clarithromycin + Simvastatin Contraindicated
- Cobicistat + Simvastatin Contraindicated
- Cyclosporine + Simvastatin Contraindicated
- Cyclosporin + Simvastatin Contraindicated
- Danazol + Simvastatin Contraindicated
Other interactions of Rifapentine
- Ledipasvir-sofosbuvir + Rifapentine Contraindicated
- Lorlatinib + Rifapentine Contraindicated
- Lurasidone + Rifapentine Contraindicated
- Ranolazine + Rifapentine Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Rifapentine with Simvastatin?
MediHelp rates the interaction as moderate. Rifapentine and Simvastatin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Rifapentine is a CYP3A4 inducer and can substantially lower simvastatin and active metabolite exposure, reducing cholesterol-lowering efficacy. Enzyme induction persists for some time after rifapentine is stopped. The concern is loss of effect, not toxicity.
How serious is the interaction between Rifapentine and Simvastatin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor LDL cholesterol and consider a higher statin dose or a non-CYP3A4 statin such as pravastatin or rosuvastatin during therapy. Reassess the dose after rifapentine is stopped.
What other medicines interact with Simvastatin?
MediHelp also lists interactions of Simvastatin with, for example, Atazanavir, Clarithromycin, Cobicistat. The full list is on the Simvastatin page.
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