HomeRitonavirRitonavir + Posaconazole

Does Ritonavir Interact with Posaconazole?

Ritonavir and Posaconazole have a moderate drug interaction according to U.S. FDA drug labeling data. Anti-HIV Drugs that are CYP3A4 Substrates Mechanism and Clinical Effect(s) Ritonavir and atazanavir are CYP3A4 substrates and posaconazole increased plasma concentrations of these drugs [see Clinical Pharmacology (12.3) ]. Prevention or Management Ritonavir and Atazanavir Monitor frequently for adverse reactions and toxicity of ritonavir and atazanavir during concomitant use. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.

Severity
Moderate
Ritonavir Class
Cytochrome P450 3A Inhibitor
Posaconazole Class
Azole Antifungal
Management
Monitor for effects
Data Source
U.S. FDA via OpenFDA

What To Tell Your Doctor or Pharmacist

If you are taking Ritonavir and your doctor is considering prescribing Posaconazole (or vice versa), make sure to:

  • Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
  • Ask whether the benefits of combining these medications outweigh the risks for your specific situation
  • Ask what symptoms to watch for that would indicate the interaction is causing problems
  • Ask whether any dosage adjustments are needed
  • Never stop or change either medication without first consulting your healthcare provider
💊 Ritonavir(Norvir)+💊 Posaconazole(Posatex)

Severity & Interaction Details

🟡
moderate
Be aware — moderate interaction
Documented interaction with manageable risk. May require dose adjustment or monitoring.
Severity scale
MinorContra
On record
Yes
Drug A class
Cytochrome P450 3A Inhibitor
Drug B class
Azole Antifungal
Source
FDA drug label - posaconazole

What this means in plain English

Anti-HIV Drugs that are CYP3A4 Substrates Mechanism and Clinical Effect(s) Ritonavir and atazanavir are CYP3A4 substrates and posaconazole increased plasma concentrations of these drugs [see Clinical Pharmacology (12.3) ]. Prevention or Management Ritonavir and Atazanavir Monitor frequently for adverse reactions and toxicity of ritonavir and atazanavir during concomitant use.

About Ritonavir and Posaconazole

Ritonavir is a Cytochrome P450 3A Inhibitor, while Posaconazole is an Azole Antifungal. You may recognize them by the brand names Norvir and Posatex. Both medications are taken by mouth. Ritonavir additionally carries an FDA boxed warning, the FDA's strongest safety alert.

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Data integrity: Every interaction shown is extracted directly from official U.S. FDA drug labeling via openFDA and the U.S. National Library of Medicine (NIH) — no interactions are invented, inferred, or manually edited. Maintained by CheckDrugInteractions.com. See our methodology or report a correction at support@checkdruginteractions.com.

Data sourced from U.S. FDA drug labeling via openFDA and the NIH National Library of Medicine, supplemented with a small number of well-established interactions from curated clinical references. For informational purposes only. Always consult your pharmacist or physician.