Can Trazodone Cause Muscle Spasms?
Yes, trazodone can cause muscle spasms and related movement disorders, though these are relatively uncommon adverse effects. The FDA drug label specifically lists muscle twitches and tremors as recognized adverse reactions, and post-marketing surveillance has documented extrapyramidal symptoms including muscle spasms 1.
Direct Evidence from FDA Labeling
The official FDA prescribing information documents several musculoskeletal and neurological adverse effects:
- Tremors occur in 3-5% of patients in controlled clinical trials, with rates varying by dosage 1
- Muscle twitches are listed as occurring at <2% incidence in controlled studies 1
- Extrapyramidal symptoms (which include muscle spasms and dystonic reactions) have been reported in post-marketing surveillance 1
- Muscle aches/pains occur in 5-6% of patients 1
Movement Disorder Mechanisms
Trazodone can trigger movement disorders through serotonergic mechanisms, particularly when combined with other serotonergic agents. A documented case report demonstrated that concurrent use of trazodone with fluoxetine caused worsening myoclonus (involuntary muscle jerking), which resolved within 7 days of discontinuing both medications 2. This suggests excessive serotonergic activity as a potential mechanism 2.
Clinical Context and Risk Factors
In overdose situations, tremors are a recognized toxic effect according to cardiac safety guidelines 3. The American Academy of Family Physicians recommends considering switching to alternative antidepressants with lower incidence of movement disorders if tremors develop on trazodone 3.
Muscle pain was significant enough to cause discontinuation in clinical studies, with 19% of patients stopping trazodone due to intolerable side effects including muscle pain 4.
Practical Clinical Approach
When muscle spasms or tremors occur with trazodone:
- Assess for drug interactions, particularly with other serotonergic medications (SSRIs, SNRIs, MAOIs) that could precipitate serotonin syndrome or excessive serotonergic activity 2
- Evaluate the dose-response relationship, as movement disorders may be dose-dependent 1
- Monitor for progression to more serious movement disorders such as extrapyramidal symptoms or myoclonus 1, 2
- Consider discontinuation if symptoms are bothersome or progressive, as symptoms typically resolve within days of stopping the medication 2
Important Caveats
Do not confuse trazodone-induced muscle symptoms with true muscle spasm requiring muscle relaxants. If genuine muscle spasm is suspected, benzodiazepines or baclofen would be more appropriate than continuing trazodone 5.
Elderly patients may be at higher risk for movement-related adverse effects, though trazodone generally has fewer anticholinergic effects than tricyclic antidepressants 6, 7.