Issues for Surgery
Risk of withdrawal symptoms if omitted (see Further Information).
Risk of serotonin syndrome if continued (see Interaction(s) with Common Anaesthetic Agents and Interaction(s) with other Common Medicines used in the Perioperative Period).
Risk of QT-interval prolongation if continued (see Interaction(s) with other Common Medicines used in the Perioperative Period).
Advice in the Perioperative period
Elective and Emergency Surgery
If a long nil by mouth (NBM) period is anticipated, or if there are concerns with enteral absorption, advice on alternative preparations / routes should be sought from a Psychiatrist.
Interaction(s) with Common Anaesthetic Agents
Central Nervous System (CNS) Excitation (Serotonin Syndrome)
Some opioids act as weak serotonin reuptake inhibitors (SRIs) and can precipitate serotonin syndrome in conjunction with other serotonergic medication. Symptoms of serotonin syndrome may occur if trazodone is given concomitantly with1, 2:
Patients should be monitored closely and the possibility of serotonin toxicity considered if patients experience altered mental state, autonomic dysfunction or neuromuscular adverse effects with concomitant treatment1.
CNS Depression (also see under Interaction(s) with other Common Medicines used in the Perioperative Period)
Trazodone has CNS depressant effects which may be additive with other medicines that also have CNS depressant effects such as1, 2:-
(Consult British National Formulary for available drugs in each class)
Interaction(s) with other Common Medicines used in the Perioperative Period
CNS Excitation (Serotonin Syndrome)
Methylthioninium chloride (methylene blue)
Monitor patients for symptoms of serotonin syndrome such as fever, tremors, diarrhoea, and agitation. Concurrent treatment should be stopped if serotonin syndrome occurs1.
CNS Depression (also see under Interaction(s) with Common Anaesthetic Agents for information on opioids)
Trazodone has CNS depressant effects which may be additive with antiemetics that also have CNS depressant effects such as cyclizine, droperidol and prochlorperazine1, 2.
Cases of QT-interval prolongation have been reported during post-marketing use of trazodone2, 3. Co-administration with other medicines known to prolong the QT-interval must be based on a careful assessment of the potential risks and benefits for each patient since the risk of torsade de pointes may increase2.
Medicines that may be used in the perioperative period that are known to prolong the QT-interval include2:-
*monitor ECG with concurrent use if risk factors for QT-interval prolongation also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia)
Clarithromycin and erythromycin are predicted to moderately increase the exposure to trazodone through inhibition of CYP3A41, 2, 3. Whilst single surgical prophylactic doses should not pose a problem, monitor for side effects and consider reducing trazodone dose if concurrent use cannot be avoided and a prolonged course is required.
Ideally trazodone should not be withdrawn abruptly as withdrawal effects may occur within 5 days of stopping treatment1; they are usually mild and self-limiting, e.g. headache, nausea, malaise3, but in some cases may be severe. The risk of withdrawal is increased if trazodone is stopped suddenly after regular administration for more than 8 weeks1.