Cariprazine and Atazanavir: 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
Atazanavir
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 build up in your body when taken together. Atazanavir (Reyataz) slows down the liver enzyme that clears cariprazine (Vraylar). That means cariprazine and its long-lasting active form can rise higher than usual, which may increase side effects like restlessness, trouble sleeping, involuntary movements, or feeling overly sedated.
The good news is that this is very manageable. Your care team can simply use a lower dose of cariprazine or dose it less often while you are on atazanavir, and adjust again if atazanavir is stopped. Please don't change anything on your own. Just talk with your doctor or pharmacist so they can tailor your dose safely.
Mechanism: Atazanavir inhibits CYP3A4, the primary enzyme metabolizing cariprazine (a CYP3A4 substrate). This raises exposure of cariprazine and its active metabolite didesmethylcariprazine (DDCAR), which has a long half-life.
- Direction: Increased cariprazine/DDCAR exposure (AUC/Cmax); enhanced pharmacologic and adverse effects (EPS, akathisia, sedation).
- Evidence: Probable. Severity major. Onset unspecified.
- Management (moderate inhibitor dosing): New start (schizophrenia/bipolar mania): 1.5 mg every other day. Bipolar depression/adjunct MDD: 1.5 mg every other day. On stable 1.5-3 mg/day: reduce to 1.5 mg every other day; on 4.5-6 mg/day: reduce to 1.5 mg once daily. When inhibitor stopped, dose may need up-titration per response.
What happens
Increased cariprazine and its major active metabolite (didesmethylcariprazine (DDCAR)) exposure
Interaction Deep Dive
Taking cariprazine (which is metabolized by CYP3A4) together with a moderate CYP3A4 inhibitor can raise the levels of both cariprazine itself and its active metabolite, didesmethylcariprazine. For patients who are beginning cariprazine while already on a moderate CYP3A4 inhibitor (in schizophrenia or bipolar mania), the recommended starting dose is 1.5 mg orally every other day, which may be raised to 1.5 mg orally every other day if warranted, guided by clinical response and tolerability. Those on a moderate CYP3A4 inhibitor being treated for bipolar depression or receiving adjunctive therapy for MDD should take 1.5 mg orally every other day. If a moderate CYP3A4 inhibitor is added for a patient already stabilized on cariprazine: for someone currently receiving 1.5 or 3 mg once daily, the cariprazine dose should be modified to 1.5 mg orally every other day upon starting the inhibitor; for someone currently on cariprazine 4.5 or 6 mg once daily, the dose should be modified to 1.5 mg orally once daily when the inhibitor is initiated. If the moderate CYP3A4 inhibitor is later stopped, an increase in the cariprazine dose may be required, based on clinical response and tolerability1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of cariprazine
How to manage this interaction
This interaction is manageable with dose adjustment and monitoring. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise.
- Your team will likely use a lower or less frequent cariprazine dose while you are on atazanavir (for example, dosing every other day instead of daily).
- The exact dose will be individualized based on why you take cariprazine and how you respond.
- If atazanavir is later stopped, your cariprazine dose may need to be increased again.
- Tell your prescriber or pharmacist about new restlessness, muscle stiffness, unusual movements, or heavy drowsiness.
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 1.5 mg/day together with erythromycin (a moderate CYP3A4 inhibitor) 500 mg twice daily for 21 days led to an increase in cariprazine AUC (0 to 24 hours) and Cmax of roughly 50% 1. In one study that included only White males taking cariprazine 1.5 mg/day and erythromycin 500 mg twice daily (n=40), the AUCs rose by 38% (cariprazine), 11% (desmethylcariprazine, an active metabolite), and 60% (didesmethylcariprazine, an active metabolite), while Cmax increased by 34%, 16%, and 62%, respectively. Tmax was unaffected by coadministration with erythromycin 2.
Common questions
Can I take Cariprazine and Atazanavir together?
Atazanavir can raise cariprazine levels and side effects, but your care team can safely manage this by lowering or spacing out your cariprazine dose. Keep taking both as prescribed and check with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cariprazine and Atazanavir 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 Atazanavir interaction managed?
This interaction is manageable with dose adjustment and monitoring. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Your team will likely use a lower or less frequent cariprazine dose while you are on atazanavir (for example, dosing every other day instead of daily). The exact dose will be individualized based on why you take cariprazine and how you resp… 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 Atazanavir 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: VRAYLAR(R) oral capsules, cariprazine oral capsules. AbbVie Inc. (per FDA), North Chicago, IL, 2024. DailyMed
- Szabo M, Hujber Z, Harsanyi J, et al: Coadministration of cariprazine with a moderate CYP3A4 inhibitor in patients with schizophrenia: implications for dose adjustment and safety monitoring. Clin Pharmacokinet 2024; 63(10):1501-1510. PubMed
Keep reading about Atazanavir
Keep reading about Cariprazine
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