Clinical Overview
Trazodone is an atypical antidepressant with sedating properties, commonly used off-label for insomnia at low doses (25-100 mg) and for depression at higher doses (150-600 mg). It has a unique mechanism combining serotonin reuptake inhibition with serotonin receptor antagonism, providing antidepressant effects with significant sedation that makes it valuable for sleep disorders.
Primary Clinical Applications
Trazodone is indicated for major depressive disorder but is more commonly used off-label for insomnia due to its sedating properties. At low doses (25-100 mg), it effectively treats sleep disorders without the dependence risks of benzodiazepines. At therapeutic antidepressant doses (150-600 mg), it treats depression, particularly when accompanied by insomnia or anxiety.
Mechanism and Clinical Benefits
Trazodone blocks serotonin reuptake and antagonizes serotonin 5-HT2A receptors, with additional activity at alpha-1 adrenergic and histamine H1 receptors. The 5-HT2A antagonism may reduce sexual side effects and improve sleep, while the antihistaminergic activity contributes to its sedating properties.
Clinical Considerations
Trazodone is generally well-tolerated but can cause significant orthostatic hypotension, particularly in elderly patients. Priapism is a rare but serious side effect requiring immediate medical attention. The medication’s sedating properties make it unsuitable for morning dosing when used for depression. It has fewer sexual side effects compared to SSRIs.
Prescribing Information
Dosing & Administration
Major Depressive Disorder – Adults:
- Initial: 150 mg daily in divided doses
- Titration: Increase by 50 mg daily every 3-4 days
- Range: 150-600 mg daily
- Maximum: 600 mg daily
Insomnia (off-label):
- Initial: 25-50 mg at bedtime
- Range: 25-100 mg at bedtime
- Maximum: 200 mg at bedtime
Elderly:
- Depression: 75 mg daily initially
- Insomnia: 25 mg at bedtime initially
- Titrate slowly due to increased sensitivity
Administration:
- Take with food to improve absorption and reduce nausea
- Largest portion or entire dose at bedtime
- Divide doses if taking >300 mg daily for depression
Indications
- Treatment of major depressive disorder
- Off-label: Insomnia, anxiety, post-traumatic stress disorder
Contraindications
- Hypersensitivity to trazodone
- Use with MAOIs (within 14 days)
- Use with linezolid or IV methylene blue
Warnings & Precautions
- Boxed Warning: Increased risk of suicidal thoughts and behavior in patients under 25 years
- Priapism: Rare (1:6000) but serious risk, more common in young males
- Orthostatic hypotension: Significant risk, especially in elderly
- Cardiac arrhythmias: Use caution in patients with cardiac disease
- Serotonin syndrome: Risk with concurrent serotonergic drugs
- Bleeding risk: Increased with anticoagulants
Drug Interactions
- MAOIs: Contraindicated – minimum 14-day washout
- CYP3A4 inhibitors: May increase trazodone levels significantly
- CNS depressants: Enhanced sedation
- Anticoagulants: Increased bleeding risk
- Digoxin, phenytoin: Increased levels reported
Adverse Reactions
Common (≥5%):
- Somnolence, dizziness, dry mouth, headache
- Nausea, constipation, blurred vision
Cardiovascular:
- Orthostatic hypotension, syncope, palpitations
Serious:
- Priapism, cardiac arrhythmias, severe hypotension
Special Populations
- Elderly: Increased risk of falls due to orthostatic hypotension
- Cardiac Disease: Use caution, monitor for arrhythmias
- Pregnancy: Category C – use only if benefits outweigh risks
- Insomnia use: Lower doses (25-100 mg) effective for sleep without antidepressant effects
Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. Always consult with qualified healthcare professionals before making any treatment decisions. Individual patient circumstances may vary significantly.
