Ketoconazole and Nisoldipine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ketoconazole
Nisoldipine
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 nisoldipine exposure
Interaction Deep Dive
Concurrent use of ketoconazole and nisoldipine may result in increased nisoldipine exposure and is contraindicated. Under no circumstances nisoldipine be coadministered with ketoconazole, and up to one week after discontinuation of treatment with ketoconazole1.
Why it happens (mechanism)
Additive negative inotropic effect of calcium channel blocker; inhibition of CYP3A4-mediated metabolism of nisoldipine
Literature reports
1 report — tap to read
a) Eight healthy male volunteers were enrolled into a randomized, non-blind, crossover study to determine the effects of ketoconazole on nisoldipine pharmacokinetics and pharmacodynamics. Participants received a single dose of nisoldipine 5 mg (immediate-release) either without pretreatment or following ketoconazole 200 mg once daily for five days. Nisoldipine AUC values increased from 1.42 mcg/h/L to 35.9 mcg/h/L in the presence of ketoconazole. Nisoldipine Cmax also increased from 1.06 mcg/L to 12.1 mcg/L when given with ketoconazole. Similar increases in AUC and Cmax were seen with the nisoldipine metabolite, M9, indicating that the side-chain hydroxylation of nisoldipine is not mediated by CYP3A4. Pharmacodynamically, the increases in nisoldipine bioavailability resulted in an increase in the heart rate of 16 beats per minute, which was seen 3 hours post-dose. Mean supine systolic blood pressure decreased by 7.5 mmHg and mean supine diastolic blood pressure decreased by 6 mmHg. The magnitude of this interaction may be somewhat less with a controlled-release preparation of nisoldipine 2.
Common questions
Can I take Ketoconazole and Nisoldipine together?
Increased nisoldipine exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ketoconazole and Nisoldipine interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Ketoconazole or Nisoldipine 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)
- Product Information: Ketoconazole oral tablet, ketoconazole oral tablet. Taro Pharmaceuticals U.S.A. Inc. (per DailyMed), Hawthorne, NY, 2024. DailyMed
- Heinig R, Adelmann HG, & Ahr G: The effect of ketoconazole on the pharmacokinetics, pharmacodynamics and safety of nisoldipine. Eur J Clin Pharmacol 1999; 55:57-60. PubMed
Keep reading about Ketoconazole
Keep reading about Nisoldipine
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:
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