Drug Guide
Molindone Hydrochloride
Classification
Therapeutic: Antipsychotic (typical antipsychotic)
Pharmacological: Dopamine D2 receptor antagonist
FDA Approved Indications
- Schizophrenia
Mechanism of Action
Molindone acts as a dopamine D2 receptor antagonist, reducing dopamine activity in the brain, which helps alleviate symptoms of schizophrenia.
Dosage and Administration
Adult: Initially 50-100 mg 2-3 times daily; doses may be adjusted based on response, with typical range 100-300 mg/day. Sometimes given in divided doses.
Pediatric: Not generally recommended for pediatric use; safety and efficacy not established.
Geriatric: Start at the low end of dosing range, monitoring closely due to potential for increased sensitivity and side effects.
Renal Impairment: Adjust dose cautiously; specific guidelines are limited, so close monitoring is recommended.
Hepatic Impairment: Use with caution; no specific dosage adjustment guidelines available.
Pharmacokinetics
Absorption: Well-absorbed after oral administration.
Distribution: Widely distributed in body tissues; appears to cross the blood-brain barrier.
Metabolism: Primarily metabolized in the liver via hepatic enzymes.
Excretion: Excreted mainly in the urine; some fecal excretion occurs.
Half Life: Approximately 10-20 hours, allowing for twice-daily dosing.
Contraindications
- Hypersensitivity to molindone or other phenothiazines.
- Com caution in patients with severe CNS depression, comatose states, or severe hepatic impairment.
Precautions
- Use cautiously in patients with seizure disorders, Parkinson's disease, or history of QT prolongation. Monitor for neuroleptic malignant syndrome and tardive dyskinesia. Caution in elderly due to risk of mortality in dementia-related psychosis.
Adverse Reactions - Common
- Sedation (Common)
- Dry mouth (Common)
- Dizziness (Common)
- Extrapyramidal symptoms (Common)
Adverse Reactions - Serious
- Neuroleptic malignant syndrome (Rare)
- QT prolongation and arrhythmias (Rare)
- Tardive dyskinesia (Rare as a chronic side effect)
Drug-Drug Interactions
- CNS depressants (enhanced sedation)
- Anticholinergics (may increase anticholinergic effects)
- Other dopamine antagonists (additive effects)
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor mental status, extrapyramidal symptoms, vital signs, and ECG. Watch for signs of neuroleptic malignant syndrome.
Diagnoses:
- Risk for falls due to sedation or orthostatic hypotension.
- Impaired physical mobility related to extrapyramidal side effects.
Implementation: Administer with food if GI upset occurs, monitor for side effects, and adjust doses as needed.
Evaluation: Assess therapeutic response and side effects regularly; adjust medication accordingly.
Patient/Family Teaching
- Do not stop medication abruptly.
- Report any signs of side effects such as muscle stiffness, fever, or irregular heartbeat.
- Avoid alcohol and CNS depressants while on this medication.
Special Considerations
Black Box Warnings:
- Increased mortality in elderly patients with dementia-related psychosis.
Genetic Factors: No specific genetic testing recommended.
Lab Test Interference: May alter certain liver function tests.
Overdose Management
Signs/Symptoms: Drowsiness, hallucinations, agitation, extrapyramidal symptoms, hypotension, seizures.
Treatment: Supportive care, monitor cardiac status, administer activated charcoal if ingestion was recent, and provide symptomatic treatment. No specific antidote available.
Storage and Handling
Storage: Store at room temperature away from light and moisture.
Stability: Stable for 2-3 years if properly stored.