Trazodone — quick, clear guide

Low doses help sleep; standard doses treat depression. Key points before you start.

Section Key information
What it is

An antidepressant (SARI: 5-HT2 antagonist and weak serotonin reuptake inhibitor). Also blocks H1 and α1 receptors — this causes sedation and may lower blood pressure.
Why it’s used
  • Insomnia (off-label): helps fall asleep and stay asleep.
  • Depression: as monotherapy or part of a combination.
How fast it works
  • Sleep benefit in 30–60 minutes after a dose.
  • Antidepressant effect builds over 2–4 weeks of regular use.
Typical doses
  • Insomnia: start 25–50 mg at bedtime; common range 25–100 mg.

  • Depression (immediate-release): start 50–100 mg 2–3×/day, titrate; usual 150–300 mg/day. Max 400 mg outpatient (up to 600 mg inpatient per doctor).

  • Extended-release: once daily in the evening with food; swallow whole.
How to take Preferably at night. Taking with food can reduce dizziness/nausea. Rise slowly to avoid orthostatic light-headedness.
Missed dose Take when remembered unless it's close to the next dose. Do not double up.
Stopping Taper gradually over 1–2 weeks (per clinician) to reduce withdrawal symptoms and relapse risk.
Common side effects

Sleepiness, dizziness, dry mouth, nausea/heartburn, constipation, headache, unsteadiness, low blood pressure when standing. Often improve within 1–2 weeks.
Serious (seek care)
  • Priapism: painful erection lasting >4 hours — go to emergency care immediately.
  • Heart rhythm problems, QT prolongation (risk higher with electrolyte issues/other QT drugs).
  • Serotonin syndrome risk (especially with other serotonergic drugs).
  • Early treatment may increase suicidal thoughts in young people — close monitoring.
  • Hyponatremia/SIADH, seizures (rare), mood switch in bipolar disorder.
Interactions — avoid/monitor
  • MAO inhibitors and for 14 days after stopping them.

  • Other serotonergic agents (SSRIs/SNRIs, triptans, linezolid, methylene blue, St. John’s wort) — serotonin syndrome risk.

  • Alcohol, benzodiazepines, opioids — additive sedation.
  • Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin, ritonavir) increase levels — dose may need reduction.
  • Enzyme inducers (carbamazepine, phenytoin, rifampin) can reduce effect.
  • Antihypertensives — may enhance blood-pressure lowering.
Use with caution

Older adults (start low), arrhythmias/QT prolongation, recent MI, liver/kidney disease, narrow-angle glaucoma, epilepsy, bipolar disorder, pregnancy/breastfeeding — clinician assessment required.
Driving & machinery Until you know your response, do not drive or operate hazardous machinery.
Monitoring Track sleep and mood; blood pressure; sodium in at-risk patients; ECG if QT-risk factors present.
Forms and strengths IR tablets 50/100/150 mg; XR 150/300 mg (availability varies by country). Generic and usually inexpensive.
Storage Room temperature, dry place, out of reach of children.
Alternatives (talk to your clinician)

For sleep: low-dose doxepin, melatonin, mirtazapine (case-by-case). For depression: SSRIs (sertraline, escitalopram, etc.), SNRIs, bupropion — individualized choice.
Quick safety notes
  • Avoid alcohol while taking trazodone.
  • Seek urgent care for chest pain, fainting, or prolonged painful erection.
  • Report any mood/behavior changes promptly.

Educational information only — not a substitute for medical advice. Your clinician will individualize dose and plan.