N-methyl-d-aspartate (NMDA) receptor antagonists for treatment of catatonia in adults: Narrative review

Abstract

Objective: While the majority of patients with catatonia fully respond to benzodiazepines or ECT, some have a partial or no response. Benzodiazepines may be contraindicated such as when delirium co-exists. This review discusses the utility of NMDA receptor antagonists as alternatives to benzodiazepines in the treatment of catatonia in adults.

Methods: A PubMed search adhering to PRISMA guidelines was conducted for articles on NMDA receptor antagonists in catatonia treatment.

Results: Thirty-seven articles, including case reports and case series were identified. Amantadine (27 cases in 13 articles) and memantine (20 cases in 14 articles) were the most commonly reported agents. Amantadine, typically used as monotherapy or adjunctive therapy with benzodiazepines, showed quick responses. Memantine, used alone or with lorazepam, demonstrated rapid responses. A small number of cases (5 cases in 4 articles) reported successful use of ketamine and esketamine, highlighting their potential role in catatonia treatment.

Conclusion: Despite limitations, NMDA receptor antagonists may be viable options when the patient is partially or not responsive to benzodiazepine, ECT is not available or may not be well tolerated, there is a concern for co-morbid delirium where benzodiazepines may be contraindicated. Further research is needed.

Keywords: Amantadine; Catatonia; Esketamine; Ketamine; Memantine; NMDA receptor antagonists.