Cobicistat 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
Cobicistat
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.
Cobicistat (Tybost) is a strong blocker of a liver enzyme called CYP3A4, and your body uses that same enzyme to break down cariprazine (Vraylar). When the enzyme is blocked, cariprazine and its long-lasting active form build up in your body. Studies with a similar blocker showed levels roughly doubling.
Higher cariprazine levels can mean more side effects, like restlessness, sleepiness, dizziness, or muscle stiffness. The good news is this is very manageable. Your care team knows to use a lower, less frequent cariprazine dose when it is combined with a drug like cobicistat. Keep taking both as prescribed, and let your pharmacist or doctor know about any new symptoms.
Mechanism: Cobicistat is a potent CYP3A4 inhibitor; cariprazine and its active metabolite didesmethylcariprazine are CYP3A4 substrates. Inhibition reduces clearance, increasing exposure (neither is a prodrug requiring activation, so effect and toxicity risk rise).
- Magnitude: Ketoconazole increased cariprazine AUC and Cmax by ~100%.
- Evidence: Probable; severity major.
- Management (per labeling): Reduce cariprazine dosing. Initiating in schizophrenia/bipolar mania: 1.5 mg every 3 days, up to 1.5 mg every other day. Bipolar depression/adjunct MDD: 1.5 mg every 3 days. Stable 1.5-3 mg/day: adjust to 1.5 mg every 3 days; stable 4.5-6 mg/day: 1.5 mg every other day. On inhibitor discontinuation, re-titrate upward.
- Monitor for EPS, akathisia, sedation.
What happens
Increased exposure to cariprazine and its active metabolite, didesmethylcariprazine
Interaction Deep Dive
Giving cariprazine (a substrate of CYP3A4) together with a potent CYP3A4 inhibitor can raise the exposure of both cariprazine itself and its active metabolite, didesmethylcariprazine. In interaction trials, combining cariprazine with ketoconazole (a strong CYP3A4 inhibitor) produced roughly a 100% rise in both AUC and Cmax. Consequently, if cariprazine therapy is being started alongside 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, move up to 1.5 mg orally every other day. For patients on a strong CYP3A4 inhibitor being treated for bipolar depression or receiving cariprazine as adjunctive therapy for MDD, the dose is 1.5 mg orally every 3 days. When a strong CYP3A4 inhibitor is added to an established cariprazine regimen, dosing must be modified: for those currently taking 1.5 or 3 mg once daily, reduce cariprazine to 1.5 mg orally every 3 days upon starting the inhibitor; for those currently on 4.5 or 6 mg once daily, reduce it to 1.5 mg orally every other day upon starting the inhibitor. Once the strong CYP3A4 inhibitor is stopped, the cariprazine dose may have to be raised according to clinical response and tolerability1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of cariprazine
How to manage this interaction
This combination is well understood and your care team has clear dosing steps to keep you safe. Because cobicistat raises cariprazine levels, a lower, less frequent cariprazine dose is typically used while you are on both.
- Keep taking both medicines exactly as prescribed. Do not change the dose on your own.
- Your prescriber will individualize your cariprazine dose (often every 3 days or every other day) while you take cobicistat.
- If cobicistat is later stopped, your team may increase the cariprazine dose again.
- Report new restlessness, tremor, stiffness, drowsiness, or dizziness 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 about 100% 1.
Common questions
Can I take Cobicistat and Cariprazine together?
Cobicistat blocks the enzyme that clears cariprazine, roughly doubling its levels, so your care team will use a lower, less frequent cariprazine dose while you take both. Keep taking both as prescribed and report any new side effects. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cobicistat 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 Cobicistat and Cariprazine interaction managed?
This combination is well understood and your care team has clear dosing steps to keep you safe. Because cobicistat raises cariprazine levels, a lower, less frequent cariprazine dose is typically used while you are on both. Keep taking both medicines exactly as prescribed. Do not change the dose on your own. Your prescriber will individualize your cariprazine dose (often every 3 days or every other… 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 Cobicistat 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 Cobicistat
Keep reading about Cariprazine
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