Drug-Induced Myoclonus: A Systematic Review

Area of Science:

• Neurology
• Pharmacology

Background:

• Myoclonus is an abnormal involuntary movement associated with various drugs and systemic conditions.
• The discovery of new drug associations necessitates a comprehensive review of medications causing drug-induced myoclonus (DIM).

Purpose of the Study:

• To systematically review and assess medications linked to drug-induced myoclonus (DIM).

Main Methods:

• A systematic review of the PubMed database was conducted using the search term "myoclonus" from 1955 to 2024.
• Medications were classified into categories and sub-categories, with evidence levels assigned to subclasses.
• Two independent reviewers assessed the retrieved articles.

Main Results:

• 1115 cases of DIM were identified from 12,097 results.
• Medications with Level A evidence included intravenous anesthetics (etomidate), cephalosporins (ceftazidime, cefepime), fluoroquinolones (ciprofloxacin), SSRIs (citalopram, escitalopram, paroxetine, sertraline), TCAs (amitriptyline), and others.
• Etomidate was the most frequently reported causative agent; neurotransmitters like serotonin, dopamine, GABA, and glutamate are implicated.

Conclusions:

• Drug-induced myoclonus (DIM) is often reversible through drug discontinuation, dose adjustment, or treatment for idiopathic myoclonus.
• DIM can be categorized into three types based on clinical presentation and pathophysiology: serotonin syndrome, non-serotonin syndrome, and unknown.
• This classification aids in understanding and managing drug-induced myoclonus.