STOP — Contraindicated
FDA contraindication — dual mechanism: CYP3A4 inhibition increases ivabradine levels + pharmacodynamic additive bradycardia.
Evidence level: STRONG
Diltiazem both increases ivabradine levels in your blood (by blocking its metabolism) AND directly slows your heart rate. This double effect can cause dangerously slow heart rate.
Diltiazem is a moderate CYP3A4 inhibitor AND also reduces heart rate. FDA ivabradine label contraindicates concurrent use with moderate CYP3A4 inhibitors that also reduce heart rate.
These medications should not be taken together. Your cardiologist should choose one or the other, or find alternatives.
Take Diltiazem and Ivabradine as prescribed by your healthcare provider. If both are taken daily, maintain consistent timing for each. Many medications compete for the same liver enzymes (CYP450 system). Your pharmacist can advise whether spacing these apart would improve efficacy.
Higher risk for: elderly, those with liver or kidney impairment, polypharmacy (5+ medications), recent medication changes, or those with multiple chronic conditions. Consult your pharmacist for specific risk factors.
Very slow heart rate (below 40 bpm), severe dizziness, fainting, extreme fatigue, shortness of breath
Switch to alternative rate control strategy. Do not combine drugs that both lower heart rate AND inhibit CYP3A4.
Discuss safer alternatives with your healthcare provider. They can recommend substitutions based on your specific health goals while minimizing interaction risks. Always bring a complete list of everything you take to your appointments.
Diltiazem both increases ivabradine levels in your blood (by blocking its metabolism) AND directly slows your heart rate. This double effect can cause dangerously slow heart rate.
Take Diltiazem and Ivabradine as prescribed by your healthcare provider. If both are taken daily, maintain consistent timing for each. Many medications compete for the same liver enzymes (CYP450 system). Your pharmacist can advise whether spacing these apart would improve efficacy.
Very slow heart rate (below 40 bpm), severe dizziness, fainting, extreme fatigue, shortness of breath
Discuss safer alternatives with your healthcare provider. They can recommend substitutions based on your specific health goals while minimizing interaction risks. Always bring a complete list of everything you take to your appointments.
Switch to alternative rate control strategy. Do not combine drugs that both lower heart rate AND inhibit CYP3A4.
Or browse the full interaction database (121,000+ pairs).