SARI (Serotonin Antagonist and Reuptake Inhibitor) Pregnancy: §4.6: trazodone should only be administered during pregnancy if considered essential by the physician. Data on a limited number (<200) of exposed pregnancies indicate no adverse effects on pregnancy or on the health of the foetus/newborn, but safety in human pregnancy has not been established; animal studies do not indicate harmful effects at therapeutic doses. On basic principles, use during the first trimester should be avoided. If used until delivery, newborns should be monitored for withdrawal symptoms. Breastfeeding: limited data indicate excretion in human breast milk is low but levels of the active metabolite are not known — decide whether to continue/discontinue breast-feeding or therapy taking account of the benefit of each.

Trazodone

Brand names: Molipaxin

Trazodone is a sedating antidepressant used for depression, particularly where anxiety or insomnia is prominent.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Depression: initially 150 mg/day in divided doses after food, or as a single dose on retiring; may be increased up to 300 mg/day

Route: Oral

Frequency: In divided doses after food, or as a single dose on retiring (the major portion of a divided dose to be taken on retiring)

Max: 300 mg/day in a single or divided doses; may be further increased to 600 mg/day in divided doses in hospitalised patients. Elderly: single doses above 100 mg should generally be avoided and it is unlikely that 300 mg/day will be exceeded.

Source: UK SPC (eMC) for Molipaxin 150mg Tablets, §4.2 (https://www.medicines.org.uk/emc/product/4197/smpc). DEPRESSION (adults): initially 150 mg/day in divided doses after food or as a single dose on retiring; this may be increased up to 300 mg/day in a single or divided doses, with the major portion of a divided dose taken on retiring; the dose may be further increased to 600 mg/day in divided doses in HOSPITALISED patients. ELDERLY: for very elderly or frail patients the recommended initial starting dose is reduced to 100 mg/day given in divided doses or as a single night-time dose; this may be incrementally increased under supervision according to efficacy and tolerance; in general single doses above 100 mg should be avoided in these patients and it is unlikely that 300 mg/day will be exceeded. DEPRESSION ACCOMPANIED BY ANXIETY: as for depression. ANXIETY: 75 mg/day increasing to 300 mg/day as necessary. A decrease in side-effects (increased resorption and decreased peak plasma concentration) can be achieved by taking trazodone after a meal. HEPATIC IMPAIRMENT: trazodone undergoes extensive hepatic metabolism and has been associated with hepatotoxicity — exercise caution when prescribing for patients with hepatic impairment, particularly severe hepatic impairment; periodic monitoring of liver function may be considered. PAEDIATRIC (not expressed as a per-kg dose in the SPC): trazodone hydrochloride is NOT recommended for use in children below the age of 18 years due to a lack of data on safety. Verify any under-18 use against a children's formulary. METHOD OF ADMINISTRATION: oral. §4.5 Interactions was not retrieved in this bundle — the interaction listed below is taken from the §4.3 Contraindications text; verify the full §4.5.

Dose adjustments

Renal

No dosage adjustment is usually necessary, but caution should be exercised when prescribing for patients with severe renal impairment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Starting dose: 150 mg in divided doses daily. May be increased by 50 mg per day every three to four days. Maximum dose: 400 mg per day in divided doses ( 2 ). Trazodone hydrochloride tablets should be taken shortly after a meal or light snack ( 2 ). Tablets should be swallowed whole or broken in half along the score line, and should not be chewed or crushed ( 2 ). When discontinued, gradual dose reduction is recommended ( 2 ). 2.1 Dose Selection An initial dose of 150 mg/day in divided doses is suggested. The dosage should be initiated at a low-dose and increased gradually, noting the clinical response and any evidence of intolerance. Occurrence of drowsiness may require the administration …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2023-08-30. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Known sensitivity to trazodone or any of the excipients
Alcohol intoxication and intoxication with hypnotics
Acute myocardial infarction

Side effects

Frequency not known — nervous system: drowsiness (trazodone is a sedative antidepressant), dizziness, vertigo, headache, restlessness, decreased alertness, tremor, blurred vision, serotonin syndrome, convulsion, neuroleptic malignant syndrome
Frequency not known — cardiac: cardiac arrhythmias including Torsade de Pointes, palpitations, premature ventricular contractions, ventricular tachycardia, bradycardia, tachycardia, ECG abnormalities (QT prolongation)
Frequency not known — vascular: orthostatic hypotension, hypertension, syncope
Frequency not known — gastrointestinal and hepatic: nausea, vomiting, dry mouth, constipation, diarrhoea, dyspepsia, stomach pain; abnormal hepatic function including jaundice and hepatocellular damage, hepatitis/fulminant hepatitis and hepatic failure with potential fatal outcome; elevated liver enzymes
Frequency not known — psychiatric and other: suicidal ideation or suicidal behaviours, confusional state, insomnia, agitation, anxiety, hallucinations, withdrawal syndrome; hyponatraemia/SIADH; priapism; blood dyscrasias (agranulocytosis, thrombocytopenia, eosinophilia, leucopenia, anaemia)

Interactions

Alcohol and hypnotics — trazodone is contraindicated in alcohol intoxication and in intoxication with hypnotics (§4.3; the full §4.5 interactions section was not retrieved in this bundle)

Clinical monograph

How it works

It inhibits serotonin reuptake and antagonises certain serotonin and histamine receptors, the latter contributing to sedation.

Prescribing in practice

Its sedative effect makes it useful where sleep is disturbed; it is often taken at night.
Postural hypotension and, rarely, priapism (a urological emergency) can occur.
Risk of serotonin syndrome with other serotonergic drugs; taper to stop.

Monitoring

Review mood and suicidal ideation early; monitor for postural symptoms.

Counselling the patient

It is usually taken at night because it causes drowsiness.
Men should seek urgent help for a prolonged or painful erection.
Do not stop it suddenly.

Evidence & guidelines

An option for depression (NICE NG222), useful where sedation is desired.

Reference: NICE CG90 (Depression); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways