Trazodone ๐
Trazodone ๐: An antidepressant with low cardiotoxicity and relatively fewer anticholinergic side-effects compared to tricyclics.
Useful where sedation is desirable.
โน๏ธ About
- Belongs to the serotonin antagonist and reuptake inhibitor (SARI) class.
- Check the BNF prescribing guidance for latest dose adjustments and cautions.
Mode of Action
- Blocks postsynaptic serotonin (5-HT2A) receptors.
- Weakly inhibits serotonin reuptake โ increases synaptic serotonin.
- Also has antihistaminic and ฮฑ1-adrenergic blocking properties โ sedation + risk of hypotension.
Indications / Dose
- Depression: 100โ300 mg/day (single or divided doses, usually at night due to sedation).
- Anxiety: 75โ300 mg/day (single or divided doses).
- Insomnia (off-label): low doses (25โ100 mg) sometimes used for sleep initiation.
Interactions
- Avoid with MAOIs (risk of serotonin syndrome).
- Caution with other serotonergic drugs (SSRIs, SNRIs, triptans, tramadol).
- Additive sedation with alcohol, benzodiazepines, or opioids.
Cautions
- Suicide risk: Antidepressants increase suicidal thoughts/behaviour in patients <25 years old.
- Epilepsy: Avoid abrupt dose changes; may lower seizure threshold.
- Liver/renal impairment: Dose adjustment and careful monitoring required.
- Cardiac disease: Use with caution in angina, conduction disorders, AV block, or recent MI.
Contraindications
- Known allergy to trazodone.
- Acute myocardial infarction.
- Acute alcohol intoxication or intoxication with hypnotics (โ CNS depression risk).
Side Effects
- Common: sedation, postural hypotension, nausea ๐คข.
- Serious: serotonin syndrome, malignant neuroleptic syndrome, QT prolongation, agranulocytosis, jaundice.
- Rare but exam-worthy: priapism (persistent painful erection requiring urgent attention).
- Ocular: acute angle-closure glaucoma (rare).
References
๐ก Clinical Pearls
- Preferred in elderly patients who cannot tolerate tricyclics due to lower anticholinergic burden.
- Useful for depression + insomnia overlap due to sedative effect.
- Always warn patients about orthostatic hypotension โ stand up slowly.
- Any painful, persistent erection = medical emergency (priapism risk).
