Can Lamictal or Cymbalta Cause Tremors?
Yes, both lamotrigine (Lamictal) and duloxetine (Cymbalta) are well-documented causes of tremor, with duloxetine causing tremor as a common adverse effect and lamotrigine inducing tremor in approximately 25% of patients on monotherapy when measured objectively.
Duloxetine (Cymbalta) and Tremor
Tremor is a recognized common adverse effect of duloxetine and all SNRIs. 1
- Duloxetine, as an SNRI, commonly causes tremor along with other adverse effects including diaphoresis, dry mouth, nausea, vomiting, dizziness, and headache 1
- In pediatric clinical trials, tremor was reported in duloxetine-treated patients (though at less than 2% incidence, it occurred more frequently than in placebo-treated patients) 2
- The FDA label confirms tremor as a documented adverse reaction in postmarketing surveillance 2
- Among second-generation antidepressants broadly, tremor is commonly reported, with approximately 63% of patients experiencing at least one adverse effect during treatment 1
Clinical context: The tremor associated with duloxetine typically resembles essential tremor and is dose-dependent 3. Risk factors include polypharmacy, older age, high doses, and male gender 3.
Lamotrigine (Lamictal) and Tremor
Lamotrigine causes tremor more frequently than clinically recognized, with objective measurements detecting pathological tremor in 25% of patients on monotherapy. 4
- Clinical tremor rating scales detect pathological tremor in only 10% of patients, but sensitive accelerometry reveals tremor in 25% of epilepsy patients receiving lamotrigine monotherapy 4
- The tremor induced by lamotrigine is characterized by intention tremor with cerebellar involvement, showing significantly higher intensity and lower frequency dispersion in both postural and intentional positions 4
- Disabling tremor can develop even after long-term use (2+ years) of lamotrigine, particularly when combined with valproate 5
- The combination of lamotrigine with valproate appears to increase tremor risk substantially 5
Important caveat: Lamotrigine-induced tremor may be underdiagnosed because routine clinical examination misses many cases that would be detected by objective measurement 4.
Management Approach
When tremor develops in patients taking either medication, discontinuation of the offending drug is the primary treatment strategy. 5, 6
- Drug-induced tremor usually resolves once the medication is discontinued, though persistent tremor (tardive tremor) may occur in some cases 3
- For lamotrigine-induced tremor, improvement typically occurs within 2.5 months after discontinuation 5
- Symptomatic treatment with tremor medications is generally ineffective and should be avoided; instead, focus on identifying and withdrawing the causative agent 5
Critical pitfall: Do not add symptomatic tremor treatments (such as benzhexol or other anti-tremor medications) without first attempting withdrawal of the suspected drug, especially when the tremor is severe or disabling 5.
Risk Assessment
- Both medications are among the most common drugs associated with tremor in clinical practice 3, 6
- SSRIs/SNRIs (including duloxetine) are well-recognized tremorogenic drugs, though less commonly acknowledged than caffeine or beta-agonists 6
- Healthcare providers should maintain high awareness of tremor as a possible adverse effect given the widespread and long-term use of both medications 5