Article type: Literature Review
Article title: Drug-Induced Myoclonus: A Systematic Review
Journal: Medicina
Year: 2025
Authors: Jamir Pitton Rissardo, Ana Letícia Fornari Caprara, Nidhi Bhal, Rishikulya Repudi, Lea Zlatin, and Ian M. Walker
E-mail: jamirrissardo@gmail.com
ABSTRACT
Background and Objectives: Myoclonus is already associated with a wide variety of drugs and systemic conditions. As new components are discovered, more drugs are suspected of causing this disabling abnormal involuntary movement. This systematic review aims to assess the medications associated with drug-induced myoclonus (DIM). Materials and Methods: Two reviewers assessed the PubMed database using the search term “myoclonus”, without language restriction, for articles published between 1955 and 2024. The medications found were divided into classes and sub-classes, and the subclasses were graded according to their level of evidence. Results: From 12,097 results, 1115 were found to be DIM. The subclasses of medications with level A evidence were intravenous anesthetics (etomidate), cephalosporins (ceftazidime, cefepime), fluoroquinolones (ciprofloxacin), selective serotonin reuptake inhibitors (citalopram, escitalopram, paroxetine, sertraline), tricyclic antidepressant (amitriptyline), glutamate antagonist (amantadine), atypical antipsychotics (clozapine, quetiapine), antiseizure medications (carbamazepine, oxcarbazepine, phenytoin, gabapentin, pregabalin, valproate), pure opioid agonist (fentanyl, morphine), bismuth salts, and mood stabilizers (lithium). The single medication with the highest number of reports was etomidate. Drug-induced asterixis is associated with a specific list of medications. The neurotransmitters likely involved in DIM are serotonin, dopamine, gamma-aminobutyric acid (GABA), and glutamate. Conclusions: DIM may be reversible with management that can include drug discontinuation, dose adjustment, and the prescription of a medication used to treat idiopathic myoclonus. Based on the main clinical constellation of symptoms and pathophysiological mechanisms found in this study, DIM can be categorized into three types: type 1 (serotonin syndrome), type 2 (non-serotonin syndrome), and type 3 (unknown).
Keywords: myoclonus; neurotoxicity; encephalopathy; drug-induced myoclonus; adverse effect; myoclonus/chemically induced; antidepressant-induced myoclonus; opioid-induced myoclonus; anti-seizure medication-induced myoclonus; antibiotic-induced myoclonus
Full text available at:
DOI
Citation
Rissardo JP, Fornari Caprara AL, Bhal N, Repudi R, Zlatin L, Walker IM. Drug-Induced Myoclonus: A Systematic Review. Medicina 2025;61(1):131.
Abstract Figure. Drug-induced myoclonus (DIM). Abbreviations: ASM, antiseizure medications; CBZ, carbamazepine; GABA, gamma-aminobutyric acid; GBP, gabapentin; IV, intravenous; OXC, oxcarbazepine; PGB, pregabalin; PHT, phenytoin; SSRIs, selective serotonin reuptake inhibitors; TCA, tricyclic antidepressants; VPT, valproate.
Figure 1. PRISMA flowchart of the screening process.
Figure 2. Classification of drug-induced myoclonus based on possible pathophysiological mechanisms.
Figure 3. Algorithm of management of drug-induced myoclonus.
Table 1. Drug-induced myoclonus and level of evidence.
Table 2. Proposed mechanisms for drug-induced myoclonus.
Table 3. Proposed classification for drug-induced myoclonus.
Table S1. Articles of Myoclonus Associated with Drugs in PubMed.
Table S2. Anesthetic-Induced Myoclonus.
Table S3. Antibiotic-Induced Myoclonus.
Table S4. Antidepressant-Induced Myoclonus.
Table S5. Antipsychotic-Induced Myoclonus.
Table S6. Antiseizure Medication-Induced Myoclonus.
Table S7. Opioid-Induced Myoclonus.
Table S8. Drug-Induced Asterixis.
