STOP — Contraindicated
FDA contraindication. Applies to ALL forms of nitrates — sublingual, transdermal, oral, IV. No safe combination exists.
Evidence level: STRONG
Sildenafil (Viagra) must not be used with isosorbide mononitrate (a long-acting nitrate for chest pain). The combination can cause severe, life-threatening low blood pressure that lasts a long time because isosorbide stays in your system.
Same PDE5 inhibitor + nitrate mechanism. Isosorbide mononitrate is a long-acting nitrate — the interaction risk is prolonged. FDA sildenafil label contraindicates all forms of nitrates.
If you take isosorbide for chest pain, do not use Viagra or any PDE5 inhibitor. Discuss alternative approaches to erectile dysfunction with your cardiologist.
Take Sildenafil and Isosorbide Mononitrate 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.
Severe dizziness, prolonged fainting, dangerously low blood pressure, heart attack symptoms
Discuss ED treatment alternatives with cardiologist. If nitrates are used regularly, PDE5 inhibitors are absolutely contraindicated.
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.
Sildenafil (Viagra) must not be used with isosorbide mononitrate (a long-acting nitrate for chest pain). The combination can cause severe, life-threatening low blood pressure that lasts a long time because isosorbide stays in your system.
Take Sildenafil and Isosorbide Mononitrate 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.
Severe dizziness, prolonged fainting, dangerously low blood pressure, heart attack symptoms
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.
Discuss ED treatment alternatives with cardiologist. If nitrates are used regularly, PDE5 inhibitors are absolutely contraindicated.
Or browse the full interaction database (121,000+ pairs).