Mifepristone and Cariprazine: 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
Mifepristone
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.
What's going on: Mifepristone slows down a liver enzyme (called CYP3A4) that your body uses to break down cariprazine (Vraylar). When that enzyme is blocked, cariprazine and its active byproduct build up in your body. In studies with a similar strong blocker, the amount of cariprazine roughly doubled.
More cariprazine in your system can mean stronger side effects, like restlessness, drowsiness, dizziness, tremor, or trouble sitting still. The good news is this is very manageable. Your care team can lower your cariprazine dose and space it out, and watch how you're doing. Please don't change anything on your own, just talk with your pharmacist or doctor.
Mechanism: Mifepristone is a strong CYP3A4 inhibitor; cariprazine is a CYP3A4 substrate (active metabolite: didesmethylcariprazine). Inhibition reduces clearance and increases exposure.
Magnitude: With ketoconazole (strong 3A4 inhibitor), cariprazine AUC and Cmax rose ~100%. Evidence: probable. Onset: unspecified.
Management (per labeling):
- Initiating cariprazine on a strong inhibitor (schizophrenia/bipolar mania): 1.5 mg every 3 days, may increase to 1.5 mg every other day per response.
- 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, dose may need re-titration.
Monitor for EPS, akathisia, sedation.
What happens
Increased exposure to cariprazine and its active metabolite, didesmethylcariprazine
Interaction Deep Dive
Taking cariprazine (which is metabolized by CYP3A4) together with a potent CYP3A4 inhibitor can raise the levels of both cariprazine and its active metabolite, didesmethylcariprazine. In interaction studies, giving cariprazine alongside ketoconazole (a strong CYP3A4 inhibitor) produced an increase of roughly 100% in both AUC and Cmax. Consequently, if cariprazine therapy is being started in a patient already receiving a strong CYP3A4 inhibitor (in schizophrenia or bipolar mania), begin with 1.5 mg orally every 3 days, and if warranted by clinical response and tolerability, raise the dose to 1.5 mg orally every other day. For patients on a strong CYP3A4 inhibitor being treated for bipolar depression or receiving adjunctive therapy for MDD, the dose is 1.5 mg orally every 3 days. When a strong CYP3A4 inhibitor is added for someone already on a stable cariprazine regimen: those receiving 1.5 or 3 mg once daily should have cariprazine changed to 1.5 mg orally every 3 days upon starting the inhibitor, while those on 4.5 or 6 mg once daily should have cariprazine adjusted to 1.5 mg orally every other day. If the strong CYP3A4 inhibitor is later stopped, the cariprazine dose may require an increase guided by clinical response and tolerability1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of cariprazine
How to manage this interaction
What your care team may do: This interaction is well recognized and has clear dosing guidance, so it can be managed. Your prescriber will typically use a lower, spaced-out cariprazine dose while you are on mifepristone.
- If you are starting cariprazine, they may begin at a reduced dose (such as 1.5 mg every 3 days).
- If you are already on cariprazine, your dose may be adjusted down and individualized to you.
- If mifepristone is later stopped, your cariprazine dose may need to be increased again.
What you should do: Keep taking both exactly as prescribed, don't adjust doses yourself, and watch for restlessness, drowsiness, dizziness, or muscle stiffness. Report these to your pharmacist or doctor.
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 an increase in total cariprazine AUC and Cmax of roughly 100% 1.
Common questions
Can I take Mifepristone and Cariprazine together?
Mifepristone can roughly double cariprazine levels by blocking its breakdown, so your care team will lower and space out the cariprazine dose and monitor you. Keep taking both as prescribed and report any new restlessness, drowsiness, or stiffness. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Mifepristone and Cariprazine 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 Mifepristone and Cariprazine interaction managed?
What your care team may do: This interaction is well recognized and has clear dosing guidance, so it can be managed. Your prescriber will typically use a lower, spaced-out cariprazine dose while you are on mifepristone. If you are starting cariprazine, they may begin at a reduced dose (such as 1.5 mg every 3 days). If you are already on cariprazine, your dose may be adjusted down and individualize… 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 Mifepristone or Cariprazine 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 Mifepristone
Keep reading about Cariprazine
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