Clindamycin and Ranolazine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ranolazine
Clindamycin
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Let's talk about taking ranolazine (Ranexa) together with clindamycin (Cleocin). Ranolazine can slow down a liver enzyme called CYP3A4, which is one of the pathways your body uses to break down clindamycin. When that pathway is slowed, more clindamycin can build up in your body, which may raise the chance of side effects.
This does not mean you can't use both. It just means your care team may want to keep a closer eye on you or adjust your dose. Please don't stop or change either medicine on your own. Check in with your pharmacist or doctor, and let them know if you notice any new or stronger side effects.
Mechanism: Ranolazine is a moderate CYP3A4 inhibitor. Clindamycin is metabolized in part by CYP3A4 to its major active metabolite. Concurrent use may increase clindamycin exposure (increased AUC/Cmax).
- Direction: Increased CYP3A4 substrate (clindamycin) exposure.
- Magnitude: Not specifically quantified for clindamycin; reference substrates showed ~40 to 100% AUC increases (up to ~400% in one atorvastatin subject).
- Onset: Unspecified.
- Evidence: Probable.
- Management: Dose adjustment may be required and individualized; monitor for enhanced clindamycin effects and GI/other adverse effects.
What happens
Increased exposure of CYP3A4 substrate
Interaction Deep Dive
When ranolazine is given together with sensitive CYP3A4 substrates or with drugs having a narrow therapeutic index (NTI), the exposure to these substrates may rise. It may therefore be necessary to modify the dosing of other sensitive CYP3A4 substrates as well as CYP3A4 substrates that have a narrow therapeutic range. One drug interaction study in healthy volunteers examined ranolazine 1000 mg twice daily combined with simvastatin 80 mg once daily, simvastatin being a CYP3A4 substrate, and found that exposure to both simvastatin and its active metabolite doubled (increased by 100%). In a comparable manner, when atorvastatin (80 mg daily) was coadministered with ranolazine (1000 mg twice daily) in healthy volunteers, the mean atorvastatin exposure rose by 40%. In a single subject, however, exposure to atorvastatin and its metabolites climbed by roughly 400% in the presence of ranolazine1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by ranolazine
How to manage this interaction
The good news is that your care team can manage this by tailoring your treatment.
- Keep taking both exactly as prescribed unless your prescriber tells you otherwise.
- Your dose may need to be adjusted and individualized by your care team, and they may monitor you more closely while you use both drugs.
- Watch for any new or worsening side effects (for example, stomach upset, diarrhea, or other unusual symptoms) and report them.
- Tell your pharmacist and prescriber that you take ranolazine and clindamycin together so they can plan and follow up.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In a drug interaction study conducted in healthy volunteers, giving ranolazine 1000 mg twice daily together with simvastatin 80 mg once daily, a CYP3A4 substrate, produced a 100% increase in exposure to simvastatin and its active metabolite. In the same way, mean exposure to atorvastatin (80 mg daily) rose by 40% when it was coadministered with ranolazine (1000 mg twice daily) in healthy volunteers. Nevertheless, in one subject the exposure to atorvastatin and its metabolites increased by roughly 400% when ranolazine was present 1.
Common questions
Can I take Clindamycin and Ranolazine together?
Ranolazine can slow the breakdown of clindamycin and raise its levels, so your care team may adjust your dose or watch you more closely. Keep taking both as prescribed and report any new side effects. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Clindamycin and Ranolazine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Clindamycin and Ranolazine interaction managed?
The good news is that your care team can manage this by tailoring your treatment. Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Your dose may need to be adjusted and individualized by your care team, and they may monitor you more closely while you use both drugs. Watch for any new or worsening side effects (for example, stomach upset, diarrhea, or other unusual… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Clindamycin or Ranolazine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: RANOLAZINE oral extended-release tablets, ranolazine oral extended-release tablets. Viona Pharmaceuticals Inc. (per Dailymed), Cranford, NJ, 2023. DailyMed
Keep reading about Ranolazine
Keep reading about Clindamycin
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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