What medications are commonly prescribed for essential tremors?

Medications for Essential Tremor

Propranolol and primidone are the first-line pharmacological treatments for essential tremor, with approximately 50% of patients experiencing significant improvement in tremor symptoms with these medications. 1, 2

First-Line Medications

Beta-Blockers

• Propranolol: 40 mg twice daily, maximum 240 mg daily 1
  • Most extensively studied and effective beta-blocker for essential tremor
  • Particularly effective for action and postural tremors of the upper limbs
  • Mechanism: Blocks peripheral beta-adrenergic receptors
  • Contraindications: Asthma, COPD, heart block, bradycardia, heart failure 1, 3

Anticonvulsants

• Primidone: Starting at 25 mg at bedtime, gradually increasing to 50-250 mg/day 2, 4
  • Similar efficacy to propranolol
  • Higher incidence of acute adverse reactions (32% vs 8% with propranolol) 4
  • Better tolerated with long-term use (fewer chronic side effects than propranolol) 4

Second-Line Medications

When first-line treatments are ineffective or contraindicated:

Alternative Beta-Blockers

• Metoprolol: Option for patients with respiratory concerns 1
• Atenolol: Fewer central nervous system effects 1
• Nadolol: Alternative when propranolol is contraindicated 1

Other Anticonvulsants

• Topiramate: 25-100 mg/day 1, 2

  • Effective alternative when first-line agents fail
  • Side effects include cognitive impairment, weight loss, paresthesias

• Gabapentin: 300-2400 mg daily, divided into three doses 1

  • Particularly useful for patients with comorbid neuropathic pain
  • Generally well-tolerated

Combination Therapy

For refractory cases, combining medications may provide better tremor control:

• Propranolol + Primidone: Consider when monotherapy with either agent provides inadequate control 2
• Addition of benzodiazepines: Clonazepam may be beneficial, especially with associated anxiety 2, 5

Treatment Algorithm

1. Assess tremor severity and impact on quality of life

   • Treatment indicated when tremor causes functional disability 1, 2

2. First-line treatment options:

   • Propranolol: Start with 40 mg twice daily, titrate as needed
   • Primidone: Start with low dose (25 mg at bedtime), gradually increase

3. If inadequate response to first-line therapy:

   • Try the alternative first-line agent
   • Consider combination therapy with propranolol and primidone

4. If still inadequate control:

   • Trial of topiramate or gabapentin
   • Consider benzodiazepines, especially with associated anxiety

5. For severe, medication-refractory tremor:

   • Evaluate for surgical candidacy (deep brain stimulation or MR-guided focused ultrasound) 1

Important Clinical Considerations

• Tolerance to medication effects may develop in approximately 12-13% of patients on either propranolol or primidone with long-term use 4
• Beta-blockers like propranolol are particularly effective for stress-induced tremor exacerbations 2
• Medications only provide symptomatic relief and do not alter the progressive nature of essential tremor 2, 6
• Surgical options (deep brain stimulation, focused ultrasound thalamotomy) should be considered for severe tremors not responding to optimal medical therapy 1, 2

Common Pitfalls to Avoid

1. Starting with too high a dose of primidone, which can cause significant acute adverse reactions - always start low and titrate slowly
2. Overlooking contraindications to propranolol (asthma, heart block, bradycardia)
3. Failing to recognize when tremor is medication-induced (e.g., by caffeine, sympathomimetics, lithium, valproate)
4. Not addressing modifiable factors that can exacerbate tremor (caffeine, stress, fatigue)
5. Continuing ineffective medication - if no benefit after adequate trial, switch to alternative agent rather than increasing dose indefinitely

The goal of treatment should be to improve function and quality of life, with the understanding that complete tremor resolution is often not achievable with pharmacological management alone.