Cariprazine and Erythromycin: 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
Erythromycin
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.
Here's what's going on. Cariprazine (Vraylar) is broken down in your body by an enzyme called CYP3A4. Erythromycin slows that enzyme down. When the enzyme works slower, cariprazine and its active breakdown product build up higher than usual. That can mean more of cariprazine's side effects, like restlessness, muscle stiffness, tremor, sleepiness, or dizziness.
The good news: this is very manageable. Your care team may simply use a lower cariprazine dose while you're on erythromycin, and adjust it again once the antibiotic is finished. Keep taking both medicines exactly as prescribed, and check in with your pharmacist or doctor so they can tailor the dose for you.
Mechanism: Erythromycin (moderate CYP3A4 inhibitor) reduces CYP3A4-mediated metabolism of cariprazine, a CYP3A4 substrate, increasing exposure of both cariprazine and its active metabolite didesmethylcariprazine (DDCAR). Neither is a prodrug requiring this enzyme for activation, so the net effect is increased pharmacologic effect and adverse-effect risk (EPS, akathisia, sedation).
Evidence: probable; severity major; onset unspecified.
Management (per labeling):
- Initiating cariprazine on a moderate inhibitor: 1.5 mg every other day, titrate per response/tolerability.
- Stable on 1.5 or 3 mg daily, adding inhibitor: reduce to 1.5 mg every other day.
- Stable on 4.5 or 6 mg daily: reduce to 1.5 mg daily.
- On inhibitor discontinuation, dose may need increasing.
What happens
Increased cariprazine and its major active metabolite (didesmethylcariprazine (DDCAR)) exposure
Interaction Deep Dive
Giving cariprazine (a substrate of CYP3A4) together with a moderate CYP3A4 inhibitor can raise the levels of both cariprazine and its active metabolite, didesmethylcariprazine. If cariprazine therapy is being started in a patient already receiving a moderate CYP3A4 inhibitor (for schizophrenia or bipolar mania), begin with 1.5 mg orally every other day; this may be raised to 1.5 mg orally every other day, if warranted and guided by clinical response and tolerability. For those on a moderate CYP3A4 inhibitor being treated for bipolar depression or as adjunctive therapy for MDD, the dose is 1.5 mg orally every other day. When a moderate CYP3A4 inhibitor is being started in a patient already on a steady cariprazine regimen: if the patient is currently taking 1.5 or 3 mg once daily, modify the cariprazine dose to 1.5 mg orally every other day upon starting the moderate inhibitor. If the patient is currently taking cariprazine 4.5 or 6 mg once daily, modify the cariprazine dose to 1.5 mg orally once daily when the moderate inhibitor is begun. Should the moderate CYP3A4 inhibitor be 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
Keep taking both medicines as prescribed unless your care team tells you otherwise. This combination is managed mainly by adjusting your cariprazine dose while you are on erythromycin.
- Your team may lower your cariprazine dose or switch it to every other day during the antibiotic course.
- When erythromycin is stopped, your cariprazine dose may be raised back toward your usual amount.
- Watch for increased side effects such as restlessness, tremor, stiffness, or drowsiness, and report them.
What to do: tell your pharmacist and prescriber you are starting erythromycin so they can individualize your dose and monitor you.
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 about 50% 1. In one study that enrolled only White males taking 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 altered by coadministration with erythromycin 2.
Common questions
Can I take Cariprazine and Erythromycin together?
Erythromycin can raise cariprazine levels and side effects, but your care team can manage this by lowering the cariprazine dose while you're on the antibiotic and adjusting it back afterward. Keep taking both as prescribed and check in with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cariprazine and Erythromycin 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 Erythromycin interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. This combination is managed mainly by adjusting your cariprazine dose while you are on erythromycin. Your team may lower your cariprazine dose or switch it to every other day during the antibiotic course. When erythromycin is stopped, your cariprazine dose may be raised back toward your usual amount. Watch for incr… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Cariprazine or Erythromycin 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 Erythromycin
Keep reading about Cariprazine
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