What is the recommended dosing frequency for trazodone (antidepressant)?

Trazodone Dosing Frequency Recommendations

Trazodone is most effectively administered as a single daily dose at bedtime for both insomnia (25-100 mg) and depression (150-300 mg), with the latter potentially requiring divided dosing if higher doses are needed. 1, 2, 3

Dosing Recommendations by Indication

For Insomnia:

• Starting dose: 25-50 mg once daily at bedtime 1
• Maximum dose: 100 mg for adults 1
• Frequency: Single bedtime dose 4

For Depression:

• Starting dose: 150 mg predominantly at bedtime 2
• Therapeutic dose: 150-300 mg daily 3
• Maximum dose:
  • 300-400 mg/day for elderly patients 1, 5
  • Up to 600 mg/day for younger adults 5
• Frequency:
  • Preferably as single bedtime dose when possible 2
  • May require division into two doses at higher ranges (>150 mg) 3, 6

Pharmacokinetic Considerations

• Half-life: 3-9 hours 2
• Elimination: Biphasic with redistribution half-life of about 1 hour and elimination half-life of 10-12 hours 6
• Absorption: Nearly complete oral absorption; food delays absorption but doesn't affect total bioavailability 6
• Metabolism: Hepatic metabolism via hydroxylation and oxidation 6

Clinical Advantages of Single Bedtime Dosing

• Studies comparing multiple daily dosing to single bedtime dosing show equal efficacy in treating depression 2
• Single nighttime dosing provides better sleep improvement with less daytime drowsiness, especially during initial treatment 2
• The once-daily formulation maintains effective blood levels for 24 hours while avoiding concentration peaks associated with side effects 3

Special Populations

• Elderly patients:

  • Lower starting doses
  • Maximum dose: 300-400 mg/day 1, 5
  • Monitor for orthostatic hypotension 1

• Patients with hepatic impairment:

  • Consider dose reduction when used with strong CYP3A4 inhibitors 1

Common Side Effects

• Sedation (most common) 2, 3
• Headache, dizziness, dry mouth 1, 3
• Orthostatic hypotension (particularly in elderly or those with cardiovascular disease) 1, 3

Important Precautions

• Rare but serious side effect: priapism 1, 3
• Use with caution in patients with cardiac issues 1
• Screen for bipolar disorder before initiating treatment 1
• Gradually taper when discontinuing (over 10-14 days) rather than stopping abruptly 1

Monitoring Recommendations

• Regular follow-up every few weeks during initial treatment to assess effectiveness and side effects 1
• Monitor for orthostatic hypotension, particularly in elderly patients 1
• Watch for cardiac arrhythmias and QT interval prolongation in susceptible patients 3