Which of the following medications can cause essential tremor: propranolol (beta-blocker), primidone, topiramate (anticonvulsant), or gabapentin (anticonvulsant)?

None of These Medications Cause Essential Tremor—They Treat It

All four medications listed (propranolol, primidone, topiramate, and gabapentin) are used to TREAT essential tremor, not cause it. This appears to be a fundamental misunderstanding of the question's premise.

First-Line Treatment Agents

• Propranolol and primidone are the established first-line treatments for essential tremor, recommended by the American Academy of Neurology with proven efficacy in up to 70% of patients 1, 2
• Propranolol (a beta-blocker) has been the gold standard for over 40 years, typically dosed at 80-240 mg/day 1, 2
• Primidone serves as an equally effective first-line alternative, particularly when propranolol is contraindicated 1, 2

Second-Line Treatment Options

• Topiramate is classified as "probably effective" for essential tremor and is suggested by guidelines for prevention of both episodic and chronic migraine, which may include tremor reduction 3, 4
• Gabapentin has limited evidence for moderate efficacy in tremor management and can be considered as a second-line option when first-line agents fail 1, 5, 4
• Both topiramate and gabapentin are anticonvulsants repurposed for tremor treatment, not tremor-causing agents 5, 6

Medications That CAN Cause Tremor

While not asked about directly, it's critical to understand that drug-induced tremor is actually caused by:

• Valproate (which ironically is also used to treat migraine) 3
• Lithium
• Selective serotonin reuptake inhibitors (SSRIs)
• Stimulants and sympathomimetics
• Corticosteroids
• Thyroid hormone excess

Clinical Algorithm for Tremor Treatment

When treating essential tremor:

1. Start with propranolol (80-240 mg/day) OR primidone as monotherapy 1, 2
2. If inadequate response, combine propranolol and primidone 5, 7
3. If first-line agents fail or are contraindicated, consider topiramate or gabapentin 1, 4
4. If medical therapy fails at maximum tolerated doses, consider surgical options (deep brain stimulation or MRgFUS thalamotomy) 1, 2

Critical Contraindications

• Propranolol must be avoided in patients with asthma/COPD, bradycardia, heart block, or decompensated heart failure 1, 2
• Common side effects of propranolol include fatigue, depression, dizziness, cold extremities, and bronchospasm 1, 2
• Primidone requires counseling about teratogenic risks (neural tube defects) in women of childbearing age 1