Acetazolamide, a carbonic anhydrase inhibitor, is used to treat a variety of ailments. It has been highlighted for its potential to benefit people with bipolar disorders, for whom there are clear current unmet treatment needs. This scoping review sought to synthesise all available evidence related to the potential effects of acetazolamide on symptoms related to bipolar disorder, acceptability and tolerability, and intervention characteristics (e.g., dose and duration). Following publication of the review protocol, the Pubmed, Embase, and PsycInfo databases were searched (all dated to 31 August 2022). A systematic approach was undertaken to identify eligible articles and extract relevant data from these. Five studies were included, assessing a total of 50 patients treated with acetazolamide. Most patients were from two open-label trials, while the others were case reports. Approximately one third of patients were experiencing psychosis or mania before treatment initiation, and one third had refractory depression. Forty-four percent of patients were estimated to achieve a response (not seemingly affected by the baseline episode type, acetazolamide dose, or duration), while a further 22% appeared to experience minimal benefits from the intervention. Acetazolamide was generally reported to be tolerated well and acceptable for up to 2 years, although reporting for acceptability and tolerability was suboptimal. The reviewed evidence is extremely limited in size and methodology (e.g., no randomised studies, blinding, or standardised outcome assessment). We posit that the current findings are sufficiently encouraging to recommend substantive clinical trials, but we emphasise that at present, the evidence is exceedingly preliminary, and there remains evident uncertainty as to whether acetazolamide could be a viable treatment for bipolar disorders.

Acetazolamide is a carbonic anhydrase inhibitor whose primary indication is to alleviate altitude sickness, but it is also used in the treatment of glaucoma, seizures and oedema. Although it has not been repurposed for psychiatric illnesses, acetazolamide has been advocated for its putative benefits in those with a bipolar disorder (BD). Because current treatment options for BD bring a variety of challenges, it is important to examine the current evidence to date in a formal synthesis. This article describes a protocol for a scoping review to do so, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). PubMed, Embase and PsycInfo will be searched for all available publications focusing on the intervention acetazolamide for people with BD. This will include non-primary and primary research of any design, focusing on any outcome, in order to comprehensively bring together the work that has been undertaken to date on this topic. Relevant data from included articles will be subject to a narrative synthesis. It is anticipated that the results from the review will help to ascertain the potential for acetazolamide to benefit people with bipolar affective disorders in the future and aid the planning of future primary research to establish this.