Nicardipine and Ritonavir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ritonavir
Nicardipine
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.
What happens
Increased calcium channel blocker exposure and increased risk of hypotension
Interaction Deep Dive
Exert caution when ritonavir is coadministered with calcium channel blockers (CYP3A substrate) and clinical monitoring is recommended2. Concomitant use of ombitasvir/paritaprevir/ritonavir plus certain calcium channel blockers may increase the calcium channel blocker exposure. If concomitant administration is necessary, decrease the dose of the calcium channel blocker and monitor for hypotension and edema. If hypotension or edema occurs, consider an additional dose decrease or an alternative to the calcium channel blocker 3.
Why it happens (mechanism)
Inhibition of CYP3A-substrate metabolism by ritonavir
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 1.
Common questions
Can I take Nicardipine and Ritonavir together?
Increased calcium channel blocker exposure and increased risk of hypotension Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nicardipine and Ritonavir 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 Nicardipine or Ritonavir 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 (3)
- 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
- Product Information: PAXLOVID(TM) oral tablets, nirmatrelvir oral tablets, ritonavir oral tablets. Pfizer Labs (per FDA), New York, NY, 2025. DailyMed
- Product Information: TECHNIVIE(TM) oral tablets, ombitasvir paritaprevir ritonavir oral tablets. AbbVie Inc. (per FDA), North Chicago, IL, 2016.
Keep reading about Ritonavir
Keep reading about Nicardipine
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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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