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Identifying the lowest effective dose of acetazolamide for the prophylaxis of acute mountain sickness: systematic review and meta-analysis.

Low EV, Avery AJ, Gupta V, Schedlbauer A, Grocott MP - BMJ (2012)

Bottom Line: No language restrictions were applied.Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup).Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.

ABSTRACT

Objectives: To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose.

Design: Systematic review and meta-analysis.

Data sources: Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied.

Study selection: Randomised controlled trials assessing the use of acetazolamide at 250 mg, 500 mg, or 750 mg daily versus placebo in adults as a drug intervention for the prophylaxis of acute mountain sickness. Included studies were required to state the administered dose of acetazolamide and to randomise participants before ascent to either acetazolamide or placebo. Two reviewers independently carried out the selection process.

Data extraction: Two reviewers extracted data concerning study methods, pharmacological intervention with acetazolamide, method of assessment of acute mountain sickness, and event rates in both control and intervention groups, which were verified and analysed by the review team collaboratively.

Data synthesis: 11 studies (with 12 interventions arms) were included in the review. Acetazolamide at doses of 250 mg, 500 mg, and 750 mg were all effective in preventing acute mountain sickness above 3000 m, with a combined odds ratio of 0.36 (95% confidence interval 0.28 to 0.46). At a dose of 250 mg daily the number needed to treat for acetazolamide to prevent acute mountain sickness was 6 (95% confidence interval 5 to 11). Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup).

Conclusions: Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness. Acetazolamide 250 mg daily is the lowest effective dose to prevent acute mountain sickness for which evidence is available.

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Related in: MedlinePlus

Fig 3 Forest plot for efficacy of acetazolamide by dose in sensitivity analysis
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fig3: Fig 3 Forest plot for efficacy of acetazolamide by dose in sensitivity analysis

Mentions: In a sensitivity analysis including only studies that used the Lake Louise scoring system to diagnose acute mountain sickness (fig 3), the estimate of intervention effects was similar between the original analysis and the sensitivity analyses, which included eight of the 11 original studies. In the 250 mg treatment group the four included studies all applied the Lake Louise scoring system,5152526 therefore sensitivity analysis was not needed. In the 500 mg subgroup, four of the original six studies were analysed13232425 giving a combined odds ratio of 0.35 (95% confidence interval 0.24 to 0.52) compared with the original odds ratio of 0.37 (0.26 to 0.52). Only one of the two studies applied the Lake Louise scoring system in the 750 mg group15 resulting in a reduced treatment effect compared with the original analysis: odds ratio 0.30 (0.12 to 0.75) compared with 0.20 (0.10 to 0.41).


Identifying the lowest effective dose of acetazolamide for the prophylaxis of acute mountain sickness: systematic review and meta-analysis.

Low EV, Avery AJ, Gupta V, Schedlbauer A, Grocott MP - BMJ (2012)

Fig 3 Forest plot for efficacy of acetazolamide by dose in sensitivity analysis
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3475644&req=5

fig3: Fig 3 Forest plot for efficacy of acetazolamide by dose in sensitivity analysis
Mentions: In a sensitivity analysis including only studies that used the Lake Louise scoring system to diagnose acute mountain sickness (fig 3), the estimate of intervention effects was similar between the original analysis and the sensitivity analyses, which included eight of the 11 original studies. In the 250 mg treatment group the four included studies all applied the Lake Louise scoring system,5152526 therefore sensitivity analysis was not needed. In the 500 mg subgroup, four of the original six studies were analysed13232425 giving a combined odds ratio of 0.35 (95% confidence interval 0.24 to 0.52) compared with the original odds ratio of 0.37 (0.26 to 0.52). Only one of the two studies applied the Lake Louise scoring system in the 750 mg group15 resulting in a reduced treatment effect compared with the original analysis: odds ratio 0.30 (0.12 to 0.75) compared with 0.20 (0.10 to 0.41).

Bottom Line: No language restrictions were applied.Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup).Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.

ABSTRACT

Objectives: To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose.

Design: Systematic review and meta-analysis.

Data sources: Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied.

Study selection: Randomised controlled trials assessing the use of acetazolamide at 250 mg, 500 mg, or 750 mg daily versus placebo in adults as a drug intervention for the prophylaxis of acute mountain sickness. Included studies were required to state the administered dose of acetazolamide and to randomise participants before ascent to either acetazolamide or placebo. Two reviewers independently carried out the selection process.

Data extraction: Two reviewers extracted data concerning study methods, pharmacological intervention with acetazolamide, method of assessment of acute mountain sickness, and event rates in both control and intervention groups, which were verified and analysed by the review team collaboratively.

Data synthesis: 11 studies (with 12 interventions arms) were included in the review. Acetazolamide at doses of 250 mg, 500 mg, and 750 mg were all effective in preventing acute mountain sickness above 3000 m, with a combined odds ratio of 0.36 (95% confidence interval 0.28 to 0.46). At a dose of 250 mg daily the number needed to treat for acetazolamide to prevent acute mountain sickness was 6 (95% confidence interval 5 to 11). Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup).

Conclusions: Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness. Acetazolamide 250 mg daily is the lowest effective dose to prevent acute mountain sickness for which evidence is available.

Show MeSH
Related in: MedlinePlus