Drug Interaction Report

Nifedipine and Nirmatrelvir: Interaction Details

A pharmacist-reviewed analysis of the Nifedipine and Nirmatrelvir interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Nifedipine

Adalat® Adalat® CC Afeditab CR Afeditab® CR Nifedical® XL Nifeditab® CR Procardia Procardia®
+

Nirmatrelvir

No brand names on record
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 325 documented Nifedipine interactions, 266 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Increased calcium channel blocker exposure and an increased risk of hypotension

Interaction Deep Dive

Concomitant administration of nirmatrelvir/ritonavir and certain calcium channel blockers may increase calcium channel blockers exposure. Use caution with coadministration and monitor clinically. Reduce dose of the calcium channel blocker as needed when coadministered with nirmatrelvir/ritonavir1.

Why it happens (mechanism)

Unknown

Literature reports

1 report — tap to read

a) The coadministration of indinavir and ritonavir with amLODIPine or dilTIAZem significantly increased exposure to amLODIPine and to a lesser extent, dilTIAZem. Subjects received either amLODIPine 5 mg once daily or dilTIAZem 120 mg once daily alone for 7 days, followed by indinavir/ritonavir 800/100 mg twice daily alone through day 19, followed by initiation of the calcium channel blocker in combination with indinavir/ritonavir through day 26. The amLODIPine AUC was increased by 89.8%, while the dilTIAZem AUC increased by 26.5% (not statistically significant). No change in the AUC or Cmax of either indinavir or ritonavir was seen when coadministered with amLODIPine or dilTIAZem 2.

Common questions

Can I take Nifedipine and Nirmatrelvir together?

Increased calcium channel blocker exposure and an increased risk of hypotension Always confirm with your pharmacist or prescriber before making any change.

How serious is the Nifedipine and Nirmatrelvir interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "unspecified". The timing of this interaction is not well characterized.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Nifedipine or Nirmatrelvir need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (2)

  1. Pfizer Labs: Fact sheet for healthcare providers: Emergency Use Authorization for PAXLOVID(TM). US Food & Drug Administration (FDA). Silver Spring, MD. 2023.
  2. Glesby MJ, Aberg JA, Kendall MA, et al: Pharmacokinetic interactions between indinavir plus ritonavir and calcium channel blockers. Clin Pharmacol Ther 2005; 78(2):143-153. PubMed
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Nifedipine

Keep reading about Nifedipine

All Nifedipine interactions (325) Nifedipine drug information
Also serious with: Rifabutin Primidone Rifapentine Rifampin
Nirmatrelvir

Keep reading about Nirmatrelvir

All Nirmatrelvir interactions (72)
Also serious with: Finerenone Midazolam Injection Flecainide Dihydroergotamine Injection
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Nifedipine + Activated Charcoal American Hellebore American Mistletoe Beer Coca Coleus Grapefruit Siberian Cocklebur + 265 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.