Darunavir 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
Darunavir
No brand names on recordCariprazine
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.
Here's what's going on. Your body normally uses an enzyme called CYP3A4 to break down cariprazine (Vraylar). Darunavir slows that enzyme down, so cariprazine and its active breakdown product can build up higher than usual in your body.
That extra buildup can mean stronger side effects, like restlessness, trouble sleeping, muscle stiffness, or feeling unusually drowsy. The good news is that this is very manageable. Don't stop or change either medicine on your own. Your care team can simply use a lower cariprazine dose while you're on darunavir and keep a closer eye on how you feel. Let them know about any new or bothersome symptoms.
Mechanism: Darunavir inhibits CYP3A4, the primary enzyme metabolizing cariprazine. This reduces clearance and increases exposure (AUC/Cmax) of cariprazine and its active metabolite didesmethylcariprazine (DDCAR). Neither drug is a prodrug in a way that reverses this; the net effect is increased cariprazine effect.
Evidence: Probable. Severity: major. Onset: unspecified.
Management: Apply moderate-CYP3A4-inhibitor dosing (note darunavir is often boosted, so effective inhibition may be stronger).
- Initiating cariprazine on inhibitor (schizophrenia/bipolar mania): 1.5 mg every other day.
- Bipolar depression/adjunctive MDD: 1.5 mg every other day.
- Stable on 1.5-3 mg daily: reduce to 1.5 mg every other day; on 4.5-6 mg daily: reduce to 1.5 mg daily.
- On inhibitor discontinuation, dose may need re-titration upward.
What happens
Increased cariprazine and its major active metabolite (didesmethylcariprazine (DDCAR)) exposure
Interaction Deep Dive
Taking cariprazine (a CYP3A4 substrate) together with a moderate CYP3A4 inhibitor can raise the levels of both cariprazine and its active metabolite, didesmethylcariprazine. If cariprazine is being started in a patient already on a moderate CYP3A4 inhibitor (in schizophrenia or bipolar mania), begin dosing at 1.5 mg orally every other day, then increase to 1.5 mg orally every other day if warranted, guided by clinical response and tolerability. For a patient on a moderate CYP3A4 inhibitor being treated for bipolar depression or receiving adjunctive therapy for MDD, use 1.5 mg orally every other day. When a moderate CYP3A4 inhibitor is being introduced in a patient already stabilized on cariprazine: for those currently taking 1.5 or 3 mg once daily, change the cariprazine to 1.5 mg orally every other day upon starting the inhibitor. For those currently taking cariprazine 4.5 or 6 mg once daily, change the cariprazine to 1.5 mg orally once daily upon starting the inhibitor. Once the moderate CYP3A4 inhibitor is stopped, an increase in the cariprazine dose may be required, depending on clinical response and tolerability1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of cariprazine
How to manage this interaction
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This combination is manageable with a tailored cariprazine dose and closer follow-up.
- Your care team will typically use a lower cariprazine dose while you're on darunavir. Depending on your current dose, this may mean taking it every other day rather than daily.
- They may monitor you more closely for side effects such as restlessness, stiffness, or drowsiness.
- If darunavir is later stopped, your cariprazine dose may need to be raised again based on how you respond.
Ask your pharmacist or prescriber to confirm the right dose for you and report any new symptoms.
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 by roughly 50% 1. In one study that enrolled only White males receiving cariprazine 1.5 mg/day and erythromycin 500 mg twice daily (n=40), AUCs rose by 38% (cariprazine), 11% (desmethylcariprazine, an active metabolite), and 60% (didesmethylcariprazine, an active metabolite), and Cmax rose by 34%, 16%, and 62%, respectively. Tmax was not affected by coadministration with erythromycin 2.
Common questions
Can I take Darunavir and Cariprazine together?
Darunavir can raise cariprazine levels and side effects by blocking its breakdown, so your care team will usually lower the cariprazine dose and watch you more closely. Keep taking both as prescribed and confirm your dose with your pharmacist or prescriber. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Darunavir 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 Darunavir and Cariprazine interaction managed?
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This combination is manageable with a tailored cariprazine dose and closer follow-up. Your care team will typically use a lower cariprazine dose while you're on darunavir. Depending on your current dose, this may mean taking it every other day rather than daily. They may monitor you more closely for side effects s… 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 Darunavir 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 (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 Darunavir
Keep reading about Cariprazine
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