Psychiatric Medications That Cause Tremor
The most common psychiatric medications that cause tremor include lithium, valproate, SSRIs/SNRIs, antipsychotics (both typical and atypical), and tricyclic antidepressants. 1, 2
Major Drug Classes and Tremor Risk
Mood Stabilizers
- Lithium is one of the most notorious tremor-inducing psychiatric medications, causing postural tremor that can be dose-dependent 1, 2, 3
- Valproate (Valproic acid/Divalproex) commonly causes tremor and can also induce parkinsonism 1, 2, 3
- Lamotrigine has been associated with postural tremor 2
Antidepressants
- SSRIs (Selective Serotonin Reuptake Inhibitors) including fluoxetine, paroxetine, sertraline, citalopram, escitalopram, and fluvoxamine cause tremor as a common side effect 4, 1, 5
- SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors) also cause tremor 1
- Tricyclic antidepressants (amitriptyline, desipramine, nortriptyline) are associated with tremor 4, 1, 5
- Bupropion can cause tremor 4
Antipsychotics
- Typical (conventional) antipsychotics including haloperidol, fluphenazine, thiothixene cause extrapyramidal symptoms including tremor as part of drug-induced Parkinsonism 4, 1
- High-potency agents (haloperidol, droperidol) are more likely to cause extrapyramidal symptoms including tremor 4
- Atypical (second-generation) antipsychotics including risperidone, olanzapine, quetiapine, aripiprazole, and ziprasidone can cause tremor, though generally less frequently than typical antipsychotics 4
- Clozapine may cause myoclonus and tremor 3
Other Psychiatric Medications
- Benzodiazepines can paradoxically cause tremor in some cases, though they are also used to treat tremor 2
Clinical Features of Drug-Induced Tremor
Drug-induced tremor typically presents as postural or action tremor resembling essential tremor, or as rest tremor resembling parkinsonian tremor, depending on the offending medication 1, 2:
- Postural tremor is most common with lithium, valproate, antidepressants 2
- Parkinsonian features (rest tremor, rigidity, bradykinesia) occur with antipsychotics due to dopamine receptor blockade 4
- Tremor frequency typically ranges from 6-12 Hz 6
Risk Factors
Key risk factors for developing drug-induced tremor include 1:
- Polypharmacy
- Male gender
- Older age
- High doses of medications
- Immediate-release preparations
- Toxic drug levels
Management Considerations
Most drug-induced tremors resolve after discontinuation of the offending medication, though some may persist (tardive tremor) 1:
- For lithium or valproate tremor: Consider beta-blockers (propranolol), primidone, gabapentin, topiramate, or benzodiazepines 2
- For antipsychotic-induced tremor: Anticholinergic agents, dose reduction, or switching to atypical antipsychotics 4
- Serotonin syndrome is a life-threatening condition that can occur when combining multiple serotonergic medications (SSRIs, SNRIs, MAOIs, tramadol, etc.) and presents with tremors, clonus, hyperreflexia, and autonomic instability 4, 3
Important Caveats
- Always distinguish drug-induced tremor from essential tremor, parkinsonian tremor, or functional tremor based on clinical features 1
- Sudden onset, unilateral presentation, or task-specific tremor should raise suspicion for alternative diagnoses 1
- When SSRIs cause tardive dyskinesia-like syndromes, this almost never occurs without prior or concurrent neuroleptic exposure 3