Side effects | RR | (95% CI) | NNTH | (95% CI) | Event rate | ||
Placebo | Acetazolamide* | ||||||
% | % | (95% CI) | |||||
Primary outcomes | |||||||
Paraesthesia | 6.5 | (5.6 to 7.3) | 2.3 | (NNTH 2 to 2.7) | 7.9 | 51.4 | (44.2 to 57.7) |
<400 mg | 5.3 | (4.1 to 6.6) | 2.9 | (NNTH 2.3 to 4.1) | 7.9 | 41.9 | (32.4 to 52.1) |
400–600 mg | 7.0 | (5.6 to 8.4) | 2.1 | (NNTH 1.7 to 2.7) | 7.9 | 55.3 | (44.2 to 66.4) |
>600 mg | 8.9 | (6.4 to 10.7) | 1.6 | (NNTH 1.3 to 2.3) | 7.9 | 70.3 | (50.6 to 84.5) |
Dysgeusia | 4.0 | (2.4 to 6.4) | 18.3 | (NNTH 10.1 to 38) | 1.8 | 7.2 | (4.3 to 11.5) |
<400 mg | 0.8 | (0.2 to 3.3) | NNTB 275 | (NNTH 24 to ∞ to NNTB 66) | 1.8 | 1.4 | (0.4 to 5.9) |
400–600 mg | 3.4 | (1.8 to 6.4) | 22.3 | (10.1 to 70.1) | 1.8 | 6.1 | (3.2 to 11.5) |
>600 mg | 8.4 | (3.2 to 19.1) | 7.4 | (3 to 25) | 1.8 | 15.1 | (5.8 to 34.4) |
Polyuria | 1.8 | (1.3 to 2.5) | 17.0 | (NNTH 9.1 to 49) | 7.5 | 13.5 | (9.8 to 18.8) |
Fatigue | 5.9 | (3.3 to 10) | 11.1 | (NNTH 6.1 to 24) | 1.8 | 10.6 | (5.9 to 18) |
Secondary outcomes | |||||||
Nausea | 2.6 | (1.6 to 3.9) | 13.0 | (NNTH 7 to 37) | 4.9 | 12.7 | (7.8 to 19.1) |
GERD | 2.6 | (1.2 to 5.3) | 16.6 | (NNTH 6.3 to 141) | 3.7 | 9.6 | (4.4 to 19.6) |
Diarrhoea | 4.8 | (1.2 to 10.2) | 11.6 | (NNTH 4.8 to 229) | 2.2 | 10.6 | (2.6 to 22.4) |
Depression | 4.0 | (1.5 to 9.6) | 17.6 | (NNTH 6 to 107) | 1.9 | 7.6 | (2.9 to 18.2) |
Dizziness | 1.2 | (0.6 to 2.2) | 100.3 | (NNTH 16.3 to ∞ to NNTB 49) | 5.3 | 6.4 | (3.2 to 11.7) |
Rash | 1.7 | (0.8 to 3.6) | 89.4 | (NNTH 23 to 246) | 1.6 | 2.7 | (1.3 to 5.8) |
Drowsiness | 4.1 | (0.9 to 17.3) | 30.1 | (NNTH 5.7 to 663) | 1.1 | 4.5 | (1 to 19) |
Tinnitus | 2.3 | (1 to 5) | 15.8 | (NNTH 5.3 to 2204) | 4.8 | 11.0 | (4.8 to 24) |
Dyspnoea | 2.6 | (0.9 to 6.4) | 18.7 | (NNTH 5.3 to 299) | 3.4 | 8.8 | (3.1 to 21.8) |
Dry mouth | 4.7 | (0.9 to 21.4) | 38.9 | (NNTH 7 to 1599) | 0.7 | 3.3 | (0.6 to 15) |
NNTH(/NNTB), number of patients needed to be treated for one additional patient to be harmed (or benefit).27 RR and NNTH/NNTB were calculated based on odds ratio and event rate in placebo arms of included trials (see methods for details).
*Calculated as placebo event rate × RR (95% CI).
GERD, gastro-oesophageal reflux disease; RR, risk ratio.