4 known interactions • 3 major • 1 moderate • 0 minor
Always disclose all medications to your healthcare providers — prescription medicines, OTC medications, vitamins, and herbal supplements. This list may not include every possible interaction. Use our Medicine Interaction Checker to screen your complete medication list.
Potentially life-threatening or causing permanent damage. Avoid combination.
May worsen condition or require dose adjustment. Monitor closely.
Usually limited clinical effect. Manage with routine monitoring.
Nitrates (all forms)
Absolutely contraindicated. Severe, potentially fatal hypotension. Unlike sildenafil (24h), tadalafil's long half-life means nitrates must be avoided for at least 48 hours after the last dose.
Management: CONTRAINDICATED. No nitrates within 48 hours of tadalafil.
Alpha-blockers
Additive hypotension. More significant than with sildenafil due to tadalafil's longer duration.
Management: Tamsulosin (uroselective) is considered safer combination than doxazosin/terazosin. For ED dosing, initiate alpha-blocker at low dose; ensure stable before adding tadalafil.
Strong CYP3A4 inhibitors (ritonavir, ketoconazole)
Markedly increase tadalafil exposure.
Management: With ritonavir: max 10mg in 72 hours. With ketoconazole/itraconazole: max 10mg once per 72 hours.
Antihypertensives
Additive hypotension — generally mild with monotherapy at standard doses.
Management: Monitor blood pressure; advise patients about postural hypotension.
Always ask your pharmacist about potential interactions with food, alcohol, and supplements specific to Tadalafil. Some medicines have significant interactions with grapefruit juice, high-fat meals, dairy products, or vitamin K-rich foods.