Acetazolamide a promising treatment for sleep apnoea

Short-term treatment with acetazolamide appears beneficial to patients with either central (CSA) or obstructive sleep apnoea (OSA), exerting favourable effects on the apnoea-hypopnoea index (AHI) and several patient-centred outcomes, including sleep quality and subjective symptoms, as shown in a study.

Researchers conducted a systematic review and meta-analysis of 28 studies evaluating the effect of oral acetazolamide in patients with OSA/CSA. About one-third of studies were conducted in Asia. In total, 542 patients were in the active treatment group and 553 were in the control group. Mean age ranged from 31 to 69 years, while mean body mass index varied between 21.9 and 38.3kg/m².

Acetazolamide doses ranged from 36 to 1,000 mg/day, with treatment lasting between 1 and 90 days (median, 6 days). Compared with control, acetazolamide lowered the AHI overall by –0.7 effect sizes (95 percent confidence interval [CI], –0.83 to –0.58; I², 0 percent; moderate quality of evidence), which corresponded to a reduction of 37.7 percent (95 percent CI, –44.7 to –31.3) or 13.8/h (95 percent CI, –16.3 to –11.4).

The AHI reduction was similar in OSA and CSA patients, but significantly greater with higher doses (at least up to 500 mg/day).

Notably, reductions in AHI were accompanied by improvements in SpO2 nadir (4.4 percent, 95 percent CI, 2.3–6.5; I², 63 percent; no evidence of effect modification; very low quality of evidence) and several secondary outcomes including sleep quality measures and blood pressure (mostly low quality of evidence).

Based on the present data, the researchers pointed out that future studies may use acetazolamide at 125–500 mg/day (1–2 doses/day; evening dose 2 hours before bedtime) with close follow-up to rule out worsening of sleep apnoea. They added that it would take a few days to achieve the maximal effect for a given dose.

Common side effects, such as paraesthesia, were dose-dependent, so it would be practical to start with 3.5 mg/kg body weight or 125–250 mg/day and titrate up every 3–5 days as needed and tolerated, the researchers said.