Cariprazine and Ketoconazole: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 16, 2026 · Source data updated Jul 16, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ketoconazole
Cariprazine
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.
These two medicines can interact. Ketoconazole slows down a liver enzyme (called CYP3A4) that your body uses to break down cariprazine (Vraylar). When that enzyme is blocked, more cariprazine builds up in your blood. In studies, levels roughly doubled.
Higher levels can mean stronger side effects, like restlessness, tremor, drowsiness, or trouble sleeping. The good news is this is very manageable. Your care team can simply lower your cariprazine dose or spread it further apart while you are on ketoconazole, and adjust it again once you stop. Please don't change anything on your own. Just tell your doctor or pharmacist you are taking both.
Mechanism: Ketoconazole is a strong CYP3A4 inhibitor; cariprazine is a CYP3A4 substrate. Inhibition reduces clearance of cariprazine and its active metabolite didesmethylcariprazine, increasing exposure.
Magnitude/evidence: In DDI studies, cariprazine AUC and Cmax rose ~100%. Evidence graded probable, severity major.
- Initiating cariprazine + strong inhibitor (schizophrenia/bipolar mania): start 1.5 mg every 3 days, may increase to 1.5 mg every other day per response/tolerability.
- Bipolar depression / adjunctive MDD: 1.5 mg every 3 days.
- Stable 1.5 or 3 mg daily: reduce to 1.5 mg every 3 days.
- Stable 4.5 or 6 mg daily: reduce to 1.5 mg every other day.
- On inhibitor discontinuation, cariprazine dose may need to be increased per clinical response.
What happens
Increased exposure to cariprazine and its active metabolite, didesmethylcariprazine
Interaction Deep Dive
When cariprazine (a substrate of CYP3A4) is given together with a potent CYP3A4 inhibitor, the exposure to both cariprazine and its active metabolite, didesmethylcariprazine, may rise. In drug interaction trials, giving cariprazine alongside ketoconazole (a strong CYP3A4 inhibitor) produced an increase of roughly 100% in both AUC and Cmax. As a result, when cariprazine therapy is being started in a patient who is also taking a strong CYP3A4 inhibitor (for schizophrenia or bipolar mania), begin with 1.5 mg orally every 3 days, then, if warranted based on clinical response and tolerability, increase to 1.5 mg orally every other day. For patients on a strong CYP3A4 inhibitor being treated for bipolar depression or receiving cariprazine as add-on therapy for MDD, the dose is 1.5 mg orally every 3 days. If a strong CYP3A4 inhibitor is being introduced while the patient is already on a stable cariprazine dose: for those currently taking 1.5 or 3 mg once daily, adjust cariprazine to 1.5 mg orally every 3 days when the strong inhibitor is started; for those currently taking 4.5 or 6 mg once daily, adjust cariprazine to 1.5 mg orally every other day when the strong inhibitor is started. Once the strong CYP3A4 inhibitor is stopped, the cariprazine dose may require an increase according to clinical response and tolerability1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of cariprazine
How to manage this interaction
Keep taking both as prescribed unless your care team tells you otherwise. This interaction is well understood and manageable with dose changes.
- Your team will likely lower your cariprazine dose or space out how often you take it while you are on ketoconazole. The exact plan depends on your current dose and why you take cariprazine.
- If you stop the ketoconazole, your cariprazine dose may need to be raised again based on how you feel and respond.
- Tell your pharmacist or prescriber you are taking both, and report any new restlessness, shakiness, drowsiness, or unusual side effects.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) In drug interaction studies, giving cariprazine 0.5 mg/day together with ketoconazole 400 mg/day led to a rise in total cariprazine AUC and Cmax of about 100% 1.
Common questions
Can I take Cariprazine and Ketoconazole together?
Ketoconazole roughly doubles cariprazine levels by blocking its breakdown, so your care team will lower or space out your cariprazine dose while you take both and readjust it when ketoconazole stops. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cariprazine and Ketoconazole 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 is the Cariprazine and Ketoconazole interaction managed?
Keep taking both as prescribed unless your care team tells you otherwise. This interaction is well understood and manageable with dose changes. Your team will likely lower your cariprazine dose or space out how often you take it while you are on ketoconazole. The exact plan depends on your current dose and why you take cariprazine. If you stop the ketoconazole, your cariprazine dose may need to be… Management is individual — always follow your own care team's guidance.
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 Cariprazine or Ketoconazole 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 (1)
- Product Information: VRAYLAR(R) oral capsules, cariprazine oral capsules. AbbVie Inc. (per FDA), North Chicago, IL, 2024. DailyMed
Keep reading about Ketoconazole
Keep reading about Cariprazine
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