Nurses Compass
Drug Guide
Pimavanserin
Classification
Therapeutic: Psychotropic agent / Antipsychotic
Pharmacological: Selective serotonergic 5-HT2A receptor inverse agonist
FDA Approved Indications
- Parkinson's disease psychosis
Mechanism of Action
Pimavanserin selectively modulates serotonin 5-HT2A receptors as an inverse agonist, which helps reduce hallucinations and delusions associated with psychosis in Parkinson's disease patients without affecting dopamine receptors.
Dosage and Administration
Adult: 34 mg once daily, can be taken with or without food.
Pediatric: Not approved for pediatric use.
Geriatric: No specific dose adjustment, but monitor elderly patients carefully due to potential increased sensitivity to side effects.
Renal Impairment: Adjust dose cautiously; no specific guidelines established.
Hepatic Impairment: Use with caution; no specific dose adjustments recommended.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed, with a high affinity for brain tissue.
Metabolism: Primarily metabolized by CYP3A4 and CYP1A2 enzymes.
Excretion: Excreted mainly via feces, minimal renal excretion.
Half Life: Approximately 55 hours.
Contraindications
- Concomitant use with other serotonergic drugs due to serotonin syndrome risk.
- Hypersensitivity to Pimavanserin.
Precautions
- Use cautiously in patients with QT prolongation, history of seizures, or who are taking other QT prolonging drugs.
- Monitor mental status as there may be an increased risk of suicidality.
Adverse Reactions - Common
- Falls, nausea, confusion, hallucinations (Common)
- Peripheral edema, constipation (Common)
Adverse Reactions - Serious
- QT prolongation, leading to serious arrhythmias (Serious (rare))
- Suicidality, worsening psychosis (Serious)
Drug-Drug Interactions
- CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin) can increase Pimavanserin levels.
- CYP3A4 inducers (e.g., rifampin, carbamazepine) can decrease levels.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for changes in mental status, hallucinations, and suicidality. ECG monitoring for QT prolongation.
Diagnoses:
- Risk for falls related to dizziness or imbalance.
- Risk for injury due to altered mental status.
- Potential for serotonin syndrome.
Implementation: Administer as prescribed. Monitor ECG periodically. Educate patient on signs of serotonin syndrome and adverse effects.
Evaluation: Assess symptom improvement and side effects regularly.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report any new or worsening hallucinations, confusion, or suicidality.
- Avoid other serotonergic drugs unless approved by provider.
- Report symptoms of dizziness or fainting.
Special Considerations
Black Box Warnings:
- Serious adverse reactions including QT prolongation, ventricular arrhythmias, and sudden death. Increased risk of death in elderly patients with dementia-related psychosis.
Genetic Factors: No specific genetic considerations noted.
Lab Test Interference: No significant interference reported.
Overdose Management
Signs/Symptoms: Severe hypotension, QT prolongation, arrhythmias, CNS depression.
Treatment: Supportive care; monitor cardiac rhythm; activated charcoal if ingestion recent; no specific antidote.
Storage and Handling
Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).
Stability: Stable under recommended storage conditions.