Therapeutic class: Antidepressants Active ingredient: Trazodone Formulation: Oral pill (tablet) Available strengths: 25 mg, 50 mg, 100 mg Regulatory status in Hong Kong: Prescription-only medication (regulated by the Hong Kong Department of Health)
Trazodone belongs to the serotonin-modulating antidepressant group. It acts primarily as a serotonin-type 2 (5-HT₂) receptor antagonist while also weakly inhibiting the reuptake of serotonin. By blocking 5-HT₂ receptors, the drug reduces overstimulation of certain brain pathways that can contribute to anxiety and sleep disturbances. The modest increase in serotonin levels further supports mood stabilization.
Key pharmacologic points:
In Hong Kong, as in many other jurisdictions, trazodone is approved for the treatment of major depressive disorder (MDD). It may also be prescribed for:
Low-dose trazodone (25-100 mg) is frequently used off-label for chronic insomnia, especially when sleep onset is difficult. Randomized controlled trials have shown modest improvements in sleep latency and continuity compared with placebo, although the evidence is less robust than for dedicated hypnotics. Because trazodone is not approved as a sleep medication, clinicians must weigh benefits against potential side effects such as daytime drowsiness or orthostatic hypotension.
Regulatory disclaimer: Off-label use requires medical supervision and individualized risk assessment.
Some clinicians prescribe trazodone for generalized anxiety disorder or panic disorder when serotonergic agents are indicated but cause intolerable side effects. Evidence is limited to small open-label studies; therefore, it remains an off-label option.
These effects are usually mild and diminish with continued therapy or dose adjustment.
Standard dosing for depression (adults)
Low-dose regimen for insomnia (off-label)
Special considerations
Administration tips
This article provides educational information about trazodone and is not a substitute for professional medical advice. Treatment decisions, including use for unapproved indications, must be made under the guidance of a qualified healthcare provider. The content is intended for informational purposes and does not constitute medical recommendations. Always consult a physician before starting, stopping, or changing any medication regimen.
Low-dose trazodone (25-100 mg) is frequently prescribed off-label for chronic insomnia. While it can improve sleep onset, it is not FDA- or HKSAR-approved for this purpose, so a prescriber must evaluate risks such as next-day drowsiness and potential drug interactions.
Trazodone tablets are typically round, white to off-white, and may bear imprint codes such as “TRAZ 25,” “TRAZ 50,” or “TRAZ 100” indicating strength. Imprints can vary by manufacturer and country of origin.
Trazodone can prolong the QT interval, which may exacerbate pre-existing cardiac conduction disorders. Patients with known QT prolongation or who take other QT-prolonging drugs should avoid trazodone or use it only under cardiology supervision.
Both classes increase serotonergic activity, but SSRIs primarily block serotonin reuptake, while trazodone adds 5-HT₂ antagonism and a sedative effect. Trazodone may be chosen when patients experience insomnia or when SSRIs cause intolerable sexual side effects, though SSRIs remain first-line due to a larger evidence base.
Yes. St. John’s Wort induces CYP3A4, potentially lowering trazodone concentrations and reducing efficacy. Conversely, combining two serotonergic agents raises the risk of serotonin syndrome. Patients should disclose all supplements to their prescriber.
Priapism is a medical emergency. Seek immediate care, as prolonged erection can cause permanent tissue damage. Prompt treatment typically involves intracavernosal medication or surgical intervention.
Trazodone is not considered habit-forming, but abrupt cessation after prolonged high-dose therapy may lead to rebound insomnia or anxiety. A gradual taper over 1-2 weeks is recommended to minimize these effects.
Food does not dramatically alter trazodone’s bioavailability, but taking the medication with a light snack may lessen stomach upset. Consistency (always with or without food) helps maintain stable plasma levels.
Because trazodone can cause sedation and impair psychomotor performance, aviation authorities generally require a minimum of 48 hours without sedation before flying. Pilots should consult their medical examiner and refer to the Hong Kong Civil Aviation Department guidelines.
Generic trazodone tablets are usually less expensive than brand-named equivalents, reflecting lower manufacturing and marketing costs. Prices vary by pharmacy and insurance coverage; patients should compare options and consider government subsidies where applicable.
