Home Drug Guide Ziprasidone Mesylate

Drug Guide

Generic Name

Ziprasidone Mesylate

Brand Names Geodon

Classification

Therapeutic: Antipsychotic, atypical

Pharmacological: Serotonin-dopamine antagonist, 5-HT2A receptor antagonist

FDA Approved Indications

Schizophrenia
Bipolar disorder (manic or mixed episodes)

Mechanism of Action

Ziprasidone works by antagonizing dopamine D2 and serotonin 5-HT2A receptors, which helps to balance neurotransmitters in the brain, reducing psychotic symptoms and mood swings.

Dosage and Administration

Adult: Initially 20 mg twice daily with food. Dose may be titrated based on response, up to 40-80 mg twice daily.

Pediatric: Not approved for pediatric use.

Geriatric: Start at lower doses due to increased sensitivity to side effects.

Renal Impairment: Adjust dosage based on clinical response and tolerability.

Hepatic Impairment: Use with caution; no specific dose adjustment recommended.

Pharmacokinetics

Absorption: Rapidly absorbed with food; bioavailability is enhanced when taken with food.

Distribution: Widely distributed; protein binding approximately 51%.

Metabolism: Primarily hepatic via aldehyde oxidase and CYP3A4 enzymes.

Excretion: Primarily fecal and urinary excretion.

Half Life: Approximately 7 hours.

Contraindications

Hypersensitivity to ziprasidone or any component of the formulation.
History of QT prolongation or congenital long QT syndrome.

Precautions

Risk of QT prolongation, ventricular arrhythmias, or sudden death; use with caution in patients with cardiovascular disease, electrolyte disturbances, or those taking other QT-prolonging drugs.
Pregnancy and lactation: Use only if clearly needed, weigh the benefits against risks.

Adverse Reactions - Common

Drowsiness (Frequent)
Dizziness (Frequent)
Nausea (Frequent)
Akathisia (Frequent)

Adverse Reactions - Serious

QT prolongation, Torsades de Pointes (Rare)
Neuroleptic Malignant Syndrome (Rare)
Anaphylactic reactions (Rare)

Drug-Drug Interactions

Other QT-prolonging agents (e.g., some antidepressants, antiarrhythmics)
CYP3A4 inhibitors or inducers
CNS depressants

Drug-Food Interactions

Alcohol, which can increase sedative effects and impair cognition.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor baseline and periodic EKGs, especially QT interval, electrolyte levels, mental status, and cardiovascular status.

Diagnoses:

Risk for cardiac arrhythmias
Impaired sensory perception
Risk for falls

Implementation: Administer with food, monitor for signs of arrhythmia, educate patient on reporting symptoms such as palpitations or dizziness.

Evaluation: Assess for improvement in psychotic symptoms, mood stabilization, and absence of adverse cardiac effects.

Patient/Family Teaching

Take medication with food to improve absorption.
Do not discontinue abruptly.
Be aware of symptoms like dizziness, fainting, or palpitations and report promptly.
Avoid alcohol and other CNS depressants unless approved by healthcare provider.

Special Considerations

Black Box Warnings:

Increased mortality in elderly patients with dementia-related psychosis.

Genetic Factors: No specific genetic testing required.

Lab Test Interference: May affect blood glucose measurements slightly due to hyperglycemia report.

Overdose Management

Signs/Symptoms: Somnolence, hypotension, QT prolongation, seizures.

Treatment: Supportive care, cardiac monitoring, activated charcoal if ingestion is recent, and magnesium sulfate or other measures for QT prolongation as needed.

Storage and Handling

Storage: Store at room temperature (20°C to 25°C), away from moisture, heat, and light.

Stability: Stable for up to 2 years in original container.