Diltiazem and Vardenafil interaction
Diltiazem and Vardenafil: the Vardenafil prescribing label flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Vardenafil (Vardenafil Hydrochloride) label · effective 2026-08-27
QT Prolongation : Patients with congenital QT syndrome or taking class IA or III antiarrhythmics should avoid using vardenafil hydrochloride tablets.
Patients taking Class 1A (for example. quinidine, procainamide) or Class III (for example, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using vardenafil hydrochloride tablets.
Potential for Drug Interactions with Strong or Moderate CYP3A4 Inhibitors Concomitant administration with strong CYP3A4 inhibitors (such as ritonavir, indinavir, cobicistat, ketoconazole) or moderate CYP3A4 inhibitors (such as erythromycin) increases plasma concentrations of vardenafil.
Dosage adjustment is necessary when vardenafil hydrochloride tablets are administered with certain CYP3A4 inhibitors [see Dosage and Administration (2.4) , and Drug Interactions (7.2) ].
Vardenafil hydrochloride tablets can potentiate the hypotensive effects of nitrates, alpha- blockers, and antihypertensives.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.