Telithromycin and Simvastatin: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 4, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telithromycin
No brand names on recordSimvastatin
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.
Telithromycin and simvastatin should not be taken together. Telithromycin is a strong blocker of a liver enzyme (called CYP3A4) that your body normally uses to break down simvastatin. When that enzyme is blocked, simvastatin builds up to much higher levels than intended.
Too much simvastatin can cause serious muscle problems. Watch for unexplained muscle pain, tenderness, or weakness, and dark or cola-colored urine. In rare cases this can harm the kidneys. The good news: your care team can manage this easily, often by pausing your simvastatin while you take the antibiotic. Please talk with your pharmacist or doctor before combining these two.
Contraindicated combination. Telithromycin is a strong CYP3A4 inhibitor; simvastatin is a CYP3A4 substrate (active drug, not a prodrug requiring this enzyme). Inhibition markedly raises simvastatin exposure (AUC/Cmax), increasing risk of myopathy and rhabdomyolysis.
- Direction: increased simvastatin effect/toxicity
- Evidence: probable
- Onset: unspecified
- Management: avoid concurrent use; if coadministration is unavoidable, temporarily suspend simvastatin for the duration of telithromycin therapy. Monitor for myalgia, weakness, and elevated CK; assess renal function if rhabdomyolysis is suspected.
What happens
Increased risk of myopathy or rhabdomyolysis
Interaction Deep Dive
Because simvastatin is metabolized by CYP3A4, giving it together with a potent CYP3A4 inhibitor raises the likelihood of myopathy and rhabdomyolysis, so this combination is contraindicated1. Should the two agents need to be used together, simvastatin should be stopped for the period that telithromycin is being administered1.2.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated simvastatin metabolism by telithromycin
How to manage this interaction
These drugs are not meant to be used at the same time. Here is what a care team typically does:
- Because telithromycin is a short antibiotic course, your prescriber will often temporarily pause simvastatin for the days you are on telithromycin, then restart it afterward.
- Sometimes a different antibiotic or a different cholesterol medicine may be chosen instead.
What you should do: Keep taking your medicines as currently prescribed, and do not stop or change anything on your own. Contact your pharmacist or prescriber before starting the antibiotic so they can adjust your plan. Report any muscle pain, weakness, or dark urine right away.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) When telithromycin 200 mg once daily for 4 days was given together with a single 80-mg dose of simvastatin, simvastatin Cmax rose 5.3-fold and AUC rose 8.9-fold. In the same way, the Cmax and AUC of simvastatin's active metabolite (simvastatin acid) rose 15-fold and 12-fold, respectively 1. When simvastatin and telithromycin were given 12 hours apart, simvastatin Cmax and AUC values rose 3.4-fold and 4-fold, respectively, while the Cmax and AUC values of the simvastatin active metabolite rose 3.2-fold and 4.3-fold, respectively 2.
Common questions
Can I take Telithromycin and Simvastatin together?
Do not take telithromycin and simvastatin together, as the antibiotic can raise simvastatin to dangerous levels and cause muscle damage; your doctor will usually pause the simvastatin during antibiotic treatment. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Telithromycin and Simvastatin interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Telithromycin and Simvastatin interaction managed?
These drugs are not meant to be used at the same time. Here is what a care team typically does: Because telithromycin is a short antibiotic course, your prescriber will often temporarily pause simvastatin for the days you are on telithromycin, then restart it afterward. Sometimes a different antibiotic or a different cholesterol medicine may be chosen instead. What you should do: Keep taking your… 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 Telithromycin or Simvastatin 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 (2)
Keep reading about Telithromycin
Keep reading about Simvastatin
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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