Atazanavir and Vardenafil interaction

Atazanavir 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.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Atazanavir (REYATAZ) label · effective 2024-12-05

Major

John’s wort ( Hypericum perforatum ) Lipid-Modifying Agents: Lomitapide, lovastatin, simvastatin Phosphodiesterase-5 (PDE-5) Inhibitor Sildenafil b when dosed as REVATIO ® for the treatment of pulmonary arterial hypertension Protease Inhibitors Indinavir Non-nucleoside Reverse Transcriptase Inhibitors Nevirapine • In patients with previously demonstrated hypersensitivity…

Contraindicationsby drug classView label on DailyMed
Moderate

REYATAZ with ritonavir: Use vardenafil with caution at reduced doses of no more than 2.5 mg every 72 hours with increased monitoring for adverse reactions.

Drug interactionsnames VardenafilView label on DailyMed
Moderate

REYATAZ : Use vardenafil with caution at reduced doses of no more than 2.5 mg every 24 hours with increased monitoring for adverse reactions.

Drug interactionsnames VardenafilView label on DailyMed
Moderate

PDE5 inhibitors: sildenafil, tadalafil, vardenafil ↑ sildenafil ↑ tadalafil ↑ vardenafil Coadministration with REYATAZ has not been studied but may result in an increase in PDE5 inhibitor-associated adverse reactions, including hypotension, syncope, visual disturbances, and priapism.

Drug interactionsby drug classView label on DailyMed
Moderate

Use of PDE5 inhibitors for erectile dysfunction: Use VIAGRA ® (sildenafil) with caution at reduced doses of 25 mg every 48 hours with increased monitoring for adverse events.

Drug interactionsby drug classView label on DailyMed

From the Vardenafil (Vardenafil Hydrochloride) label · effective 2026-08-27

Moderate

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.

Warnings and precautionsby drug classView label on DailyMed
Moderate

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) ].

Warnings and precautionsby drug classView label on DailyMed
Moderate

In vivo studies Strong CYP3A4 inhibitors Ketoconazole (200 mg once daily) produced a 10-fold increase in vardenafil AUC and a 4-fold increase in maximum concentration (C max ) when co-administered with vardenafil hydrochloride tablets (5 mg) in healthy volunteers.

Drug interactionsby drug classView label on DailyMed
Moderate

Moderate CYP3A4 inhibitors Erythromycin (500 mg t.i.d.) produced a 4-fold increase in vardenafil AUC and a 3-fold increase in C max when co­ administered with vardenafil hydrochloride tablets 5 mg in healthy volunteers.

Drug interactionsby drug classView label on DailyMed
Moderate

…recommended not to exceed a single 5 mg dose of vardenafil hydrochloride tablets in a 24-hour period when used in combination with erythromycin. [See Dosage and Administration (2.4) and Warnings and Precautions (5) .] Although specific interactions have not been studied, other CYP3A4 inhibitors, including grapefruit juice would likely increase vardenafil exposure.

Drug interactionsby drug classView label on DailyMed

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Not 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.