Indinavir 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
Indinavir
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.
These two medicines can build up together. Indinavir strongly blocks a liver enzyme called CYP3A4, which is the same enzyme your body uses to break down cariprazine (Vraylar). When that pathway is slowed, more cariprazine and its long-lasting active form stay in your system. In studies with a similar strong blocker, levels roughly doubled.
More drug in your body can mean more side effects, like restlessness, tremor, sleepiness, or movement problems. The good news is this is very manageable. Your care team can lower your cariprazine dose or space it out, and watch how you respond. Please don't change anything on your own, just check with your pharmacist or doctor.
Effect: Increased exposure to cariprazine and its active metabolite didesmethylcariprazine.
Mechanism: Indinavir is a strong CYP3A4 inhibitor; cariprazine is a CYP3A4 substrate. Inhibition reduces clearance, raising AUC/Cmax. Ketoconazole data showed ~100% increases in AUC and Cmax. Evidence: probable; severity major.
Management (per labeling):
- New start, schizophrenia/bipolar mania: 1.5 mg every 3 days, may increase to 1.5 mg every other day per response/tolerability.
- Bipolar depression/MDD adjunct: 1.5 mg every 3 days.
- Adding inhibitor to stable dose: if on 1.5 or 3 mg daily to 1.5 mg every 3 days; if on 4.5 or 6 mg daily to 1.5 mg every other day.
- On inhibitor discontinuation, cariprazine dose may need increasing.
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, exposure to both cariprazine and its active metabolite, didesmethylcariprazine, may rise. In studies of drug interactions, giving cariprazine alongside ketoconazole (a strong CYP3A4 inhibitor) produced an increase of roughly 100% in both AUC and Cmax. Consequently, if cariprazine is being started in a patient already receiving a strong CYP3A4 inhibitor (for schizophrenia or bipolar mania), the initial dose should be 1.5 mg by mouth every 3 days, which may be raised to 1.5 mg orally every other day if warranted, according to clinical response and tolerability. For those 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. If a strong CYP3A4 inhibitor is added while a patient is already stable on cariprazine, the cariprazine dose should be modified as follows: for patients currently taking 1.5 or 3 mg once daily, change cariprazine to 1.5 mg orally every 3 days when the strong inhibitor is begun; for patients currently taking 4.5 or 6 mg once daily, change cariprazine to 1.5 mg orally every other day when the strong inhibitor is begun. Should the strong CYP3A4 inhibitor later be 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
This interaction is expected and can be managed by adjusting your cariprazine dose. Keep taking both medicines as prescribed unless your care team tells you otherwise.
- Your team will typically lower or space out your cariprazine dose while you are on indinavir (for example, taking it every 3 days or every other day instead of daily).
- The exact dose is individualized based on your response and how well you tolerate it, so expect closer monitoring.
- If indinavir is later stopped, your cariprazine dose may need to be raised again.
Ask your pharmacist or prescriber before making any change, and report new restlessness, tremor, drowsiness, or unusual movements.
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 approximately 100% 1.
Common questions
Can I take Indinavir and Cariprazine together?
Indinavir can roughly double cariprazine levels by blocking CYP3A4, so your care team will lower or space out your cariprazine dose and monitor you. Don't change anything yourself, just confirm the plan with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Indinavir 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 Indinavir and Cariprazine interaction managed?
This interaction is expected and can be managed by adjusting your cariprazine dose. Keep taking both medicines as prescribed unless your care team tells you otherwise. Your team will typically lower or space out your cariprazine dose while you are on indinavir (for example, taking it every 3 days or every other day instead of daily). The exact dose is individualized based on your response and how… 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 Indinavir 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 Indinavir
Keep reading about Cariprazine
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