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Clarithromycin + Ranolazine

STOP — Contraindicated

FDA contraindication on ranolazine label. Strong CYP3A4 inhibitors contraindicated due to QT prolongation risk from elevated ranolazine levels.

Evidence level: STRONG

What this interaction means

Clarithromycin is contraindicated with ranolazine (Ranexa) because it dramatically increases ranolazine levels, which can prolong the QT interval and cause dangerous heart rhythm problems.

How it works (mechanism)

Clarithromycin is a strong CYP3A4 inhibitor. Ranolazine is metabolized by CYP3A4. FDA ranolazine label contraindicates strong CYP3A4 inhibitors. Increased ranolazine levels prolong QT interval.

Practical advice

Do not take clarithromycin with ranolazine. Use alternative antibiotics.

Timing

Follow each medication's specific timing instructions. Clarithromycin — check if it requires an empty stomach or should be taken with food. Ranolazine follows its normal schedule. Complete the full antibiotic course as prescribed.

Risk factors

Higher risk for: those with liver or renal impairment, elderly, concurrent use of nephrotoxic or hepatotoxic drugs, history of C. difficile infection, or those on narrow therapeutic index medications (warfarin, digoxin).

Symptoms to watch for

Dizziness, fainting, palpitations, irregular heartbeat, nausea, constipation

What to tell your doctor

Use alternative antibiotics. If strong CYP3A4 inhibitor is unavoidable, temporarily discontinue ranolazine.

Safer alternatives

Antibiotic interactions are often temporary (duration of treatment). Space supplements and probiotics 2-3 hours away from antibiotic doses. Ask your pharmacist if timing adjustments can reduce the interaction risk.

Frequently asked questions

Can I take Clarithromycin and Ranolazine together?

Clarithromycin is contraindicated with ranolazine (Ranexa) because it dramatically increases ranolazine levels, which can prolong the QT interval and cause dangerous heart rhythm problems.

When should I take Clarithromycin vs Ranolazine?

Follow each medication's specific timing instructions. Clarithromycin — check if it requires an empty stomach or should be taken with food. Ranolazine follows its normal schedule. Complete the full antibiotic course as prescribed.

What symptoms should I watch for if I combine Clarithromycin and Ranolazine?

Dizziness, fainting, palpitations, irregular heartbeat, nausea, constipation

Are there safer alternatives to combining Clarithromycin with Ranolazine?

Antibiotic interactions are often temporary (duration of treatment). Space supplements and probiotics 2-3 hours away from antibiotic doses. Ask your pharmacist if timing adjustments can reduce the interaction risk.

What should I tell my doctor about taking Clarithromycin and Ranolazine?

Use alternative antibiotics. If strong CYP3A4 inhibitor is unavoidable, temporarily discontinue ranolazine.

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