PT - JOURNAL ARTICLE AU - Borges, Letizia Goncalves AU - Bonakdarpour, Borna TI - Memantine-induced chorea and dystonia AID - 10.1136/practneurol-2016-001470 DP - 2017 Apr 01 TA - Practical Neurology PG - 133--134 VI - 17 IP - 2 4099 - http://pn.bmj.com/content/17/2/133.short 4100 - http://pn.bmj.com/content/17/2/133.full SO - Pract Neurol2017 Apr 01; 17 AB - Memantine is an uncompetitive N-methyl-d-aspartate receptor antagonist and probably also has an indirect dopaminergic action at high concentrations. We describe a person with Alzheimer's disease who developed chorea and dystonia after inadvertently doubling of her daily dose by taking extended-release (XR) memantine twice daily, rather than once daily (planned dose memantine XR, 21 mg once daily), after the drug was switched from immediate release (IR, 10 mg twice daily). Memantine is rarely associated with movement disorders, but this case emphasises the need for awareness of potential problems when switching from memantine IR to XR.