Generic Name

Trazodone Hydrochloride

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Classification

FDA Approved Indications

• Major depressive disorder
• Off-label uses include insomnia and anxiety

Mechanism of Action

Trazodone acts primarily by inhibiting the reuptake of serotonin (5-HT), and antagonizing serotonin 5-HT2 receptors, contributing to its antidepressant and sedative effects.

Dosage and Administration

Adult: Initially 150 mg/day in divided doses or as a single dose at bedtime; dose may be increased slowly based on response and tolerability, up to a maximum of 400 mg/day.

Pediatric: Not approved for pediatric use.

Geriatric: Start at a lower dose due to increased sensitivity; usual starting dose is 75 mg at bedtime, titrate as needed.

Renal Impairment: Adjust dose cautiously; consider lower starting doses.

Hepatic Impairment: Use with caution; monitor closely, start at lower dose.

Pharmacokinetics

Absorption: Well-absorbed after oral administration.

Distribution: Widely distributed, protein binding approximately 89%.

Metabolism: Hepatic via extensive first-pass metabolism; active metabolite is m-CPP.

Excretion: Metabolites excreted mainly in urine.

Half Life: Approximately 7-10 hours for the parent compound, longer for metabolites.

Contraindications

• History of hypersensitivity to trazodone
• Use with other serotonergic drugs unless managed carefully.

Precautions

• Risk of priapism, orthostatic hypotension, sedation, and suicidal thoughts, especially in young adults and during initial treatment. Use cautiously in patients with cardiac disease, seizures, or history of bipolar disorder.

Adverse Reactions - Common

• Sedation, dizziness (Common)
• Dry mouth, blurred vision (Common)
• Nausea, vomiting (Common)

Adverse Reactions - Serious

• Priapism (Rare)
• Serotonin syndrome (when combined with other serotonergic agents) (Rare)
• Arrhythmias, QT prolongation (Rare)
• Orthostatic hypotension (Less common)

Drug-Drug Interactions

• Other serotonergic drugs (e.g., SSRIs, SNRIs, MAOIs) increase risk of serotonin syndrome.
• CYP3A4 inhibitors may increase trazodone levels.
• CYP3A4 inducers may decrease effectiveness.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed.
• Do not discontinue abruptly to avoid withdrawal.
• Caution regarding sedation and operating machinery.
• Report any signs of priapism, or unusual mood changes.
• Avoid alcohol and other CNS depressants.

Special Considerations

Black Box Warnings:

• Risk of suicidal thoughts and behaviors in children, adolescents, and young adults.
• Potential for arrhythmias, including QT prolongation.

Genetic Factors: Genetic variations affecting CYP3A4 may influence drug levels.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Drowsiness, hypotension, rapid heart rate, seizures, priapism, and possible coma.

Treatment: Supportive care, monitoring vital signs, activated charcoal if ingested recently, and symptomatic treatment. Cardiovascular monitoring for arrhythmias.

Storage and Handling

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

Stability: Stable in original container. Protect from light and moisture.