Generic Name

Cariprazine Hydrochloride

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Classification

FDA Approved Indications

• Schizophrenia in adults
• Bipolar disorder (manic/mixed episodes and maintenance treatment)

Mechanism of Action

Cariprazine acts mainly as a partial agonist at dopamine D2 and D3 receptors, with a higher affinity for D3 receptors, and serotonin 5-HT1A receptors, and as an antagonist at 5-HT2A receptors. This modulation helps balance dopamine and serotonin neurotransmission, alleviating psychotic and mood symptoms.

Dosage and Administration

Adult: Start at 1.5 mg once daily, can be increased to a target dose of 3 mg/day, titrated based on response and tolerability.

Pediatric: Not approved for pediatric use.

Geriatric: Use with caution; start at lower doses due to increased sensitivity in older adults.

Renal Impairment: Adjust dose based on severity; consult prescribing information.

Hepatic Impairment: Use caution; consider starting at lower doses due to altered metabolism.

Pharmacokinetics

Absorption: Well absorbed orally, with peak plasma concentrations in about 3-4 hours.

Distribution: High protein binding (~71-77%).

Metabolism: Metabolized primarily by CYP3A4 and to a lesser extent by CYP2D6; active metabolites include DCAR and DDCAR.

Excretion: Excreted mainly in feces (~76%) and urine (~13%).

Half Life: Approximately 2-4 days, which supports once-daily dosing.

Contraindications

• Hypersensitivity to cariprazine or any component of the formulation.

Precautions

• Use with caution in patients with cardiovascular disease, history of orthostatic hypotension, seizure disorders, or risk of suicide.
• Monitor for signs of worsening depression or suicidal thoughts, especially during initial therapy.

Adverse Reactions - Common

• Akathisia (Common)
• Dizziness (Common)
• Extrapyramidal symptoms (Common)
• Somnolence (Common)
• Nausea (Common)

Adverse Reactions - Serious

• Neuroleptic malignant syndrome (Rare)
• Tardive dyskinesia (Rare)
• Orthostatic hypotension (Uncommon)
• Changes in blood glucose or lipid levels (Uncommon)

Drug-Drug Interactions

• CYP3A4 inducers (e.g., carbamazepine, rifampin) may decrease effectiveness.
• CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin) may increase plasma levels.

Drug-Food Interactions

• Grapefruit juice may increase levels of cariprazine.

Drug-Herb Interactions

• St. John's Wort may reduce effectiveness.

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed.
• Report any worsening symptoms or side effects.
• Avoid alcohol, CNS depressants, and hazardous activities until stabilized.
• Sun sensitivity: use sun protection.
• Inform about potential for drowsiness or dizziness.

Special Considerations

Black Box Warnings:

• Elderly patients with dementia-related psychosis treated with antipsychotics are at increased risk of death.
• Suicidal thoughts and behaviors: May increase risk in some patients.

Genetic Factors: Metabolism varies with CYP3A4/CYP2D6 polymorphisms affecting drug levels.

Lab Test Interference: No significant interference reported.

Overdose Management

Signs/Symptoms: Drowsiness, tachycardia, agitation, extrapyramidal symptoms.

Treatment: Supportive care; monitor vital signs; consider gastric lavage or activated charcoal if ingestion is recent; no specific antidote.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F).

Stability: Stable for at least 24 months when stored properly.