Effect of famotidine on cognitive and behavioral dysfunctions induced in post-COVID-19 infection: A randomized, double-blind, and placebo-controlled study.

Objectives: This is an investigation of the efficacy and safety of famotidine, a selective histamine H2 receptor antagonist, on improvement of cognitive impairment, depression and anxiety symptoms developing post-COVID-19, in a 12-week, randomized controlled trial.

Methods: A total of 50 patients with a confirmed diagnosis of COVID-19 and a score ≤ 23 on the Mini-Mental State Examination (MMSE) test or a score ≤ 22 on the Montreal Cognitive Assessment (MoCA) were randomly assigned to either the famotidine (40 mg twice daily) or the placebo group. Changes in MMSE scores at weeks 6 and 12 were the primary outcome, while changes in other scales were the secondary outcomes. Participants and evaluators were blinded.

Results: At weeks 6 and 12, patients in the famotidine group had significantly higher MMSE scores (p = 0.014, p < 0.001, respectively). Regarding the MoCA scale, the famotidine group had a significantly higher score at weeks 6 and 12 (p = 0.001, p < 0.001, respectively). Considering the HAM-D scale (Hamilton Depression Rating Scale), at weeks 6 and 12, the famotidine group experienced a larger reduction (p = 0.009, p = 0.02, respectively). Additionally, comparison of the HAM-A scale scores (Hamilton Anxiety Rating Scale) at weeks 6 and 12 showed a statistically significant larger reduction in the famotidine group (p = 0.04, p = 0.02, respectively). The two groups did not differ in the frequency of adverse effects.

Conclusion: Our study supports safety and efficacy of famotidine in treating cognitive impairment, depression and anxiety symptoms induced by COVID-19.

Trial Registration: This trial was registered at the Iranian registry of clinical trials (IRCT: www.irct.ir; registration number: IRCT20090117001556N138).