Home Drug Guide Mesoridazine Besylate

Drug Guide

Generic Name

Mesoridazine Besylate

Brand Names Serentil

Classification

Therapeutic: Antipsychotic, typical

Pharmacological: Dopamine antagonist (phenothiazine)

FDA Approved Indications

Schizophrenia

Mechanism of Action

Mesoridazine blocks dopamine D2 receptors in the brain, reducing psychotic symptoms.

Dosage and Administration

Adult: Varies based on clinical response; typically starting at 10-50 mg per day, titrated as needed.

Pediatric: Not generally recommended; limited data.

Geriatric: Use with caution; start at lower doses, monitor closely.

Renal Impairment: Adjust dose based on renal function; specific guidelines not well established.

Hepatic Impairment: Use with caution; dose adjustments may be necessary.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses blood-brain barrier.

Metabolism: Primarily hepatic via CYP2D6 and CYP3A4 enzymes.

Excretion: Excreted in urine and feces.

Half Life: Approximately 13-36 hours.

Contraindications

Hypersensitivity to mesoridazine or other phenothiazines.
Comatose states.
Bone marrow suppression.

Precautions

Use cautiously in elderly patients due to risk of torsades de pointes.
Avoid in patients with QT prolongation, history of cardiac arrhythmias, or electrolyte imbalance.
Use with caution in cardiovascular disease, cerebrovascular disease, or seizure disorders.
Pregnancy Category C; potential risks versus benefits must be considered.

Adverse Reactions - Common

Sedation (Common)
Dry mouth (Common)
Dizziness (Common)
Blurred vision (Common)
Constipation (Common)

Adverse Reactions - Serious

QT prolongation leading to torsades de pointes (Serious and potentially life-threatening)
Cardiac arrhythmias (Serious)
Neuroleptic malignant syndrome (Serious)
Agranulocytosis (Rare)
Seizures (Rare)

Drug-Drug Interactions

Other QT-prolonging agents (e.g., certain antidepressants, antiarrhythmics).
CNS depressants (enhanced sedation).
CYP450 inhibitors or inducers affecting metabolism.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor cardiac status (ECG), electrolytes, and mental status.

Diagnoses:

Risk for cardiac arrhythmias related to QT prolongation.
Risk for falls due to sedation.

Implementation: Administer as prescribed, monitor ECG periodically, especially in elderly and those with cardiac history.

Evaluation: Assess for relief of psychotic symptoms and adverse effects.

Patient/Family Teaching

Report any signs of dizziness, fainting, or irregular heartbeat.
Avoid alcohol and other CNS depressants.
Do not discontinue abruptly; dose should be tapered.
Keep follow-up appointments for cardiac monitoring.

Special Considerations

Black Box Warnings:

Potential for QT prolongation and sudden death.

Genetic Factors: CYP2D6 poor metabolizers may have higher plasma levels leading to increased risk of adverse effects.

Lab Test Interference: None significant documented.

Overdose Management

Signs/Symptoms: Severe sedation, hypotension, QT prolongation, seizures.

Treatment: Supportive care, monitoring cardiac rhythm, activated charcoal if within an hour of ingestion, magnesium sulfate for QT prolongation, and possibly intravenous fluids.

Storage and Handling

Storage: Store at room temperature, away from light and moisture.

Stability: Stable according to manufacturer specifications.