Ritonavir and Vardenafil interaction
Ritonavir and Vardenafil: both prescribing labels 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 Ritonavir (Norvir) label · effective 2026-07-23
…lovastatin, simvastatin ○ Microsomal triglyceride transfer protein (MTTP) Inhibitor: lomitapide ○ Non-opioid Analgesic (selective blocker of Na v 1.8 sodium channels): suzetrigine ○ PDE5 Inhibitor: sildenafil (Revatio ® ) when used for the treatment of pulmonary arterial hypertension ○ Sedative/Hypnotics: triazolam, orally administered midazolam • NORVIR is contraindicated…
Use of PDE5 inhibitors for pulmonary arterial hypertension (PAH): Sildenafil (Revatio ® ) is contraindicated [see Contraindications ( 4 ) ] .
Particular caution should be used when prescribing sildenafil, tadalafil or vardenafil in patients receiving ritonavir.
PDE5 Inhibitors: avanafil sildenafil, tadalafil, vardenafil ↑ avanafil ↑ sildenafil ↑ tadalafil ↑ vardenafil Sildenafil when used for the treatment of pulmonary arterial hypertension (Revatio ® ) is contraindicated due to the potential for sildenafil-associated adverse events, including visual abnormalities, hypotension, prolonged erection, and syncope [see Contraindications…
Coadministration of ritonavir with these drugs may result in an increase in PDE5 inhibitor associated adverse events, including hypotension, syncope, visual changes, and prolonged erection.
From the Vardenafil (Vardenafil Hydrochloride) label · effective 2026-08-27
…2.5 mg vardenafil hydrochloride tablets dose in a 24-hour period when used in combination with indinavir. [See Dosage and Administration (2.4) and Warnings and Precautions (5.2) .] Ritonavir (600 mg b.i.d.) co-administered with vardenafil hydrochloride tablets 5 mg resulted in a 49-fold increase in vardenafil AUC and a 13 fold increase in vardenafil C max .
Ritonavir significantly prolonged the half-life of vardenafil to 26 hours.
Consequently, it is recommended not to exceed a single 2.5 mg vardenafil hydrochloride tablets dose in a 72-hour period when used in combination with ritonavir. [See Dosage and Administration (2.4) and Warnings and Precautions (5.2) .] .
Ritonavir and Indinavir: Upon concomitant administration of 5 mg of vardenafil hydrochloride tablets with 600 mg BID ritonavir, the C max and AUC of ritonavir were reduced by approximately 20%.
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.
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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.