Cariprazine

• Schizophrenia
• Bipolar I Disorder
• Bipolar Depression
• Major Depressive Disorder (adjunct)

Cariprazine is an atypical antipsychotic medication approved for the treatment of schizophrenia, bipolar I disorder, and major depressive disorder. This medication has a unique pharmacological profile with preferential binding to dopamine D3 receptors, which may contribute to its efficacy in treating negative symptoms and cognitive deficits.

Mechanism of Action

Cariprazine is a dopamine D3 and D2 receptor partial agonist with preferential binding to D3 receptors. It also acts as a partial agonist at serotonin 5-HT1A receptors and an antagonist at 5-HT2B and 5-HT2A receptors. The D3 receptor preference is approximately 10-fold higher than D2, which distinguishes cariprazine from other antipsychotics. D3 receptors are concentrated in limbic regions involved in motivation, emotion, and cognition. The partial agonist activity provides stabilization of dopamine signaling, potentially improving positive, negative, and cognitive symptoms while minimizing extrapyramidal side effects.

Available Formulations

Cariprazine is available as oral capsules in 1.5 mg, 3 mg, 4.5 mg, and 6 mg strengths. The capsules can be taken with or without food. Due to the medication's long half-life (including active metabolites with half-lives of 1-3 weeks), dose adjustments should be made at intervals of at least 2 weeks.

Medical Uses

Cariprazine is FDA-approved for the treatment of schizophrenia in adults, acute treatment of manic or mixed episodes associated with bipolar I disorder in adults, depressive episodes associated with bipolar I disorder (bipolar depression) in adults, and as adjunctive treatment for major depressive disorder (MDD) in adults. Clinical trials demonstrated improvement in negative symptoms of schizophrenia, which is often difficult to treat with other antipsychotics.

Dosing Guidelines

For schizophrenia, the recommended dose range is 1.5-6 mg once daily, starting at 1.5 mg on day 1, and can be increased to 3 mg on day 2, with further adjustments in 1.5-3 mg increments based on response and tolerability. For bipolar mania, dosing is similar with a range of 3-6 mg daily. For bipolar depression, the recommended dose is 1.5 mg daily, increased to 3 mg on day 15 based on response. For MDD adjunctive therapy, start at 1.5 mg daily with potential increase to 3 mg. Dose adjustment is needed with CYP3A4 inhibitors.

Important Safety Information

Cariprazine carries a boxed warning regarding increased mortality in elderly patients with dementia-related psychosis (not approved for this use) and increased risk of suicidal thoughts and behaviors in patients under 24 with MDD. Other serious risks include neuroleptic malignant syndrome, tardive dyskinesia, metabolic changes, orthostatic hypotension, falls, leukopenia/neutropenia, seizures, and potential cognitive and motor impairment. The long half-life means adverse effects may take weeks to resolve after discontinuation.

Drug Interactions

Strong CYP3A4 inhibitors (ketoconazole, itraconazole, clarithromycin) increase cariprazine levels; dose should be reduced by half if used with these agents. Strong CYP3A4 inducers (rifampin, carbamazepine, phenytoin) may substantially decrease levels; concomitant use is not recommended. Moderate CYP3A4 inhibitors may require dose adjustment. Due to the long half-life, it may take several weeks for interactions to manifest or resolve.

Special Populations

There are limited data on use during pregnancy; neonates exposed to antipsychotics during the third trimester may experience extrapyramidal or withdrawal symptoms. Cariprazine and its metabolites are present in rat milk; breastfeeding is not recommended. Safety and efficacy have not been established in pediatric patients. Clinical trials included limited elderly patients; no overall differences in safety were observed but increased sensitivity is possible. No dose adjustment is needed for mild to moderate renal or hepatic impairment; use is not recommended in severe impairment.