Ketoconazole Topical and Almotriptan: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Almotriptan
No brand names on recordKetoconazole Topical
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 almotriptan exposure
Interaction Deep Dive
In a randomized, open-label, two-way, crossover pharmacokinetic study (n=16), a clinically significant increase in the Cmax (61%) and AUC (57%) of almotriptan (a CYP3A4 substrate) was observed with concomitant administration of ketoconazole (a potent CYP3A4 inhibitor); however, there were no associated changes to the adverse event profile and vital signs associated with almotriptan administration2. A starting dose of almotriptan 6.25 mg and a maximum daily dose of almotriptan 12.5 mg is recommended in patients receiving concomitant therapy with a potent CYP3A4 inhibitor, such as ketoconazole; concomitant use of these agents should be avoided in patients with renal or hepatic impairment 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated almotriptan metabolism
Literature reports
1 report — tap to read
a) A statistically significant increase in maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) of almotriptan was observed with concomitant administration of ketoconazole. Sixteen volunteers were included in a randomized, open-label, two-way crossover study. Each subject received both of the following treatments with a 1-week washout period: (A) ketoconazole 400 mg on day 1 to 3 and almotriptan 12.5 mg on day 2 and (B) almotriptan 12.5 mg on day 2. The mean AUC for almotriptan was increased by 57% with concomitant ketoconazole administration, and the mean Cmax was increased by 61%. Oral clearance and volume of distribution of almotriptan were decreased with ketoconazole coadministration. Renal clearance of almotriptan was reduced approximately 16% by ketoconazole. While the effects were clinically significant, there were no associated changes to the adverse event profile and vital signs associated with almotriptan administration. Based on these results, no dosage adjustment is necessary when ketoconazole and almotriptan are coadministered 2.
Common questions
Can I take Ketoconazole Topical and Almotriptan together?
Increased almotriptan exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ketoconazole Topical and Almotriptan interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
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 "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Ketoconazole Topical or Almotriptan 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 anything you'd monitor while I'm on both?
References (2)
Keep reading about Almotriptan
Keep reading about Ketoconazole Topical
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist