Drug interactions
Red yeast rice + Simvastatin
Severity: Major
Red yeast rice and Simvastatin: major 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
Red yeast rice contains monacolin K, identical to lovastatin, so combining it with simvastatin duplicates statin therapy. This increases the risk of myopathy and rhabdomyolysis without added benefit.
What this interaction means in plain words
Red yeast rice and Simvastatin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Red yeast rice belongs to Gastrointestinal Tract; Simvastatin belongs to Cardiovascular.
Why it happens
Therapeutic duplication of HMG-CoA reductase inhibition causing additive muscle toxicity.
What to do
Avoid the combination and discontinue red yeast rice. Monitor for muscle pain, weakness and CK elevation if exposure has occurred.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Red yeast rice and Simvastatin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
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 Red yeast rice
- Red yeast rice + Ritonavir Contraindicated
- Red yeast rice + Saquinavir Contraindicated
- Red yeast rice + Tipranavir Contraindicated
- Atazanavir + Red yeast rice Major
- Atorvastatin + Red yeast rice Major
- Conivaptan + Red yeast rice Major
Frequently asked questions
Can I take Red yeast rice with Simvastatin?
MediHelp rates the interaction as major. Red yeast rice and Simvastatin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Red yeast rice contains monacolin K, identical to lovastatin, so combining it with simvastatin duplicates statin therapy. This increases the risk of myopathy and rhabdomyolysis without added benefit.
How serious is the interaction between Red yeast rice and Simvastatin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and discontinue red yeast rice. Monitor for muscle pain, weakness and CK elevation if exposure has occurred.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
