What is the initial dosing of trazodone (antidepressant medication) for adults with depression or insomnia?

Initial Dosing of Trazodone for Depression and Insomnia

The initial dosing of trazodone for adults with depression is 150 mg/day in divided doses, while for insomnia, a lower starting dose of 25-50 mg at bedtime is recommended. 1, 2

Dosing for Depression

Trazodone dosing for depression follows a specific protocol:

• Initial dose: 150 mg/day in divided doses 1
• Titration: Increase by 50 mg/day every 3-4 days based on clinical response and tolerance 1
• Maximum dose:
  • Outpatients: 400 mg/day in divided doses
  • Inpatients (more severely depressed): up to 600 mg/day in divided doses 1

Administration Guidelines

• Take shortly after a meal or light snack
• Can be swallowed whole or broken along score line
• Once adequate response is achieved, dosage may be gradually reduced 1

Dosing for Insomnia

For insomnia, trazodone is commonly prescribed at lower doses:

• Initial dose: 25 mg per day at bedtime 2
• Maximum dose: 200-400 mg per day in divided doses 2
• Typical effective dose for insomnia: 50-100 mg at bedtime 3

Important Considerations for Insomnia Use

• The American Academy of Sleep Medicine notes that evidence for trazodone's efficacy when used alone for insomnia is relatively weak, particularly in elderly patients 4
• Low-dose trazodone (≤100mg/day) has been shown to be effective for treating both primary insomnia and secondary insomnia (including insomnia related to depression) 3
• Use with caution in patients with premature ventricular contractions 2

Special Populations

Elderly Patients

• Lower starting doses are recommended
• Consider alternative treatments such as low-dose doxepin for insomnia in elderly patients due to its favorable safety profile 4

Patients with Cardiovascular Concerns

• Use with caution in patients with cardiovascular disease
• Monitor for orthostatic hypotension, especially in older adults 5

Side Effects and Monitoring

The most common side effects include:

• Somnolence/drowsiness (most common)
• Headache
• Dizziness
• Xerostomia (dry mouth) 5

Trazodone has minimal anticholinergic activity but may be associated with:

• Orthostatic hypotension
• QT interval prolongation
• Cardiac arrhythmias
• Rare episodes of priapism 5

Drug Interactions

• Strong CYP3A4 inhibitors: Consider reducing trazodone dose based on tolerability 1
• Strong CYP3A4 inducers: Consider increasing trazodone dose based on therapeutic response 1
• MAOIs: Allow at least 14 days between discontinuing an MAOI and starting trazodone, and vice versa 1

Discontinuation

When discontinuing trazodone:

• Gradually reduce the dosage rather than stopping abruptly
• Monitor for discontinuation symptoms 1

Trazodone's relatively favorable side effect profile (low incidence of weight gain and sexual dysfunction) compared to SSRIs may improve treatment adherence, particularly for patients with insomnia as a component of their depression 5.