Nimodipine and Ritonavir interaction

Nimodipine and Ritonavir: 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 Nimodipine (Nymalize) label · effective 2024-08-30

Major

Therefore, the concomitant administration of NYMALIZE and strong CYP3A4 inhibitors should generally be avoided [ see Warnings and Precautions (5.3) ].

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Moderate

…Increased Risk of Hypotension with Strong CYP3A4 Inhibitors Concomitant use of strong inhibitors of CYP3A4, such as some macrolide antibiotics (e.g., clarithromycin, telithromycin), some HIV protease inhibitors (e.g., indinavir, nelfinavir, ritonavir, saquinavir), some HCV protease inhibitors (e.g., boceprevir, telaprevir), some azole antimycotics (e.g., ketoconazole,…

Warnings and precautionsby drug classView label on DailyMed
Moderate

Possible Reduced Efficacy with Strong CYP3A4 Inducers Concomitant use of strong CYP3A4 inducers (e.g., carbamazepine, phenobarbital, phenytoin, rifampin, St.

Warnings and precautionsby drug classView label on DailyMed
Moderate

CYP3A4 Inhibitors Nimodipine plasma concentration can be significantly increased when concomitantly administered with strong CYP3A4 inhibitors.

Drug interactionsby drug classView label on DailyMed
Moderate

Strong CYP3A4 inhibitors include some members of the following classes: macrolide antibiotics (e.g., clarithromycin, telithromycin), HIV protease inhibitors (e.g., indinavir, nelfinavir, ritonavir, saquinavir), HCV protease inhibitors (e.g., boceprevir, telaprevir), azole antimycotics (e.g., ketoconazole, itraconazole, posaconazole, voriconazole), conivaptan,…

Drug interactionsby drug classView label on DailyMed

From the Ritonavir (Norvir) label · effective 2026-07-23

Moderate

The impact on the PR interval of co-administration of ritonavir with other drugs that prolong the PR interval (including calcium channel blockers, beta-adrenergic blockers, digoxin and atazanavir) has not been evaluated.

Warnings and precautionsby drug classView label on DailyMed
Moderate

Calcium channel blockers: diltiazem, nifedipine, verapamil ↑ calcium channel blockers Caution is warranted and clinical monitoring of patients is recommended.

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.