Can sertraline (selective serotonin reuptake inhibitor) exacerbate tremors in patients with Parkinson's disease and will the tremor subside over time?

Sertraline's Effect on Tremor in Parkinson's Disease Patients

Sertraline can exacerbate tremors in Parkinson's disease patients, but these tremor symptoms typically improve over time as the patient continues treatment. 1, 2

Mechanism and Evidence

Sertraline, like other selective serotonin reuptake inhibitors (SSRIs), can cause or worsen tremor through its effects on serotonergic pathways. This is particularly relevant in Parkinson's disease where:

• Serotonergic dysfunction in motor circuitries correlates with severity of action-postural tremor in PD 3
• The relationship between dopaminergic and serotonergic systems is complex in PD tremor pathophysiology 4
• Tremor in PD involves both basal ganglia and cerebello-thalamo-cortical circuits 5

A prospective study examining sertraline in PD patients found that while some patients experienced worsening of tremor initially, the overall impact on parkinsonism was positive over time 2. The study showed improvement in UPDRS (Unified Parkinson's Disease Rating Scale) domains with continued sertraline treatment at a mean dose of 66 mg.

Expected Timeline for Tremor Improvement

When tremor occurs or worsens with sertraline initiation:

• Behavioral activation/agitation including tremor typically occurs early in SSRI treatment, with dose increases, or with concomitant medications 6
• These side effects usually improve quickly after SSRI dose decrease or with continued treatment 6
• A full therapeutic trial of an antidepressant requires at least 4-8 weeks 6
• Most tremor side effects will subside within 1-2 weeks of continued treatment 6

Management Approach for Tremor in PD Patients on Sertraline

1. Initial assessment:

   • Determine if tremor is rest, postural, or kinetic (all three can occur in PD) 4
   • Evaluate timing of tremor worsening in relation to sertraline initiation

2. If tremor worsens after starting sertraline:

   • Consider continuing treatment at current dose if tremor is tolerable
   • Monitor closely for 2-4 weeks to assess if tremor subsides with continued treatment
   • If tremor is severe or disabling, options include:
     • Reducing sertraline dose temporarily
     • Slowing the titration schedule (using increments of initial dose every 5-7 days) 6

3. For persistent tremor:

   • Consider adjusting dopaminergic medications as tremor-predominant PD may respond to levodopa, dopamine agonists, or anticholinergics 7
   • Evaluate for other contributing factors (anxiety, caffeine, other medications)

Important Considerations

• Benefit-risk assessment: Depression in PD significantly impacts quality of life and mortality; treating depression often outweighs the risk of temporary tremor exacerbation
• Medication interactions: Sertraline has less effect on metabolism of other medications compared to other SSRIs 6, making it relatively safer in patients on multiple medications
• Alternative approaches: If tremor remains problematic, consider switching to another antidepressant, though many have similar side effect profiles

Cautions

• Monitor for serotonin syndrome, especially if the patient is on multiple serotonergic medications 6
• Be aware that SSRIs can cause behavioral activation/agitation that may be confused with worsening parkinsonism 6
• Avoid abrupt discontinuation of sertraline as this can lead to withdrawal symptoms 6

The evidence suggests that while sertraline may temporarily worsen tremor in some PD patients, this effect is usually transient, and the overall impact of treating depression often outweighs this side effect as treatment continues.