Re: “Drug Use and Misuse in the Mountains: A UIAA MedCom Consensus Guide for Medical Professionals” by Donegani et al. (High Alt Med Biol 17:157–184)

Dear Editor-in-Chief,

My colleagues and I recently conducted a systematic review and meta-analysis of pharmacological agents for improving sleep quality at high altitude (Kong et al., 2018). Several conclusions in this study disagree with the UIAA MedCom Consensus Guide for Medical Professionals published in High Altitude Medicine & Biology (Donegani et al., 2016).

In our study, we supported confirmed evidence of the efficacy and safety of nonbenzodiazepine agents (zaleplon and zolpidem) in improving both objective and subjective quality of sleep without impairing ventilation at high altitude. In contrast, acetazolamide and theophylline both reduced the sleep efficiency index. However, temazepam did not show any superiority over placebo in terms of subjective sleep quality, particularly the quicker onset of sleep and better sleep quality.

However, the studies on theophylline and acetazolamide cited by the UIAA MedCom Consensus Guide could not reach confirming conclusions on their positive effect. Some studies have low methodological quality, especially in unclear random sequence generation and allocation concealment (Fischer et al., 2004), which may result in selection bias. One was a review article (Wickramasinghe et al., 1999) and not a controlled trial. Another trial of acetazolamide did not find a reduction in the incidence of periodic breathing at high altitude (Rodway et al., 2011). Therefore, the UIAA MedCom Consensus Guide for Medical Professionals should be updated. We suggest that acetazolamide, theophylline, and temazepam should be downgraded to Grade 2A, whereas nonbenzodiazepines should be upgraded to Grade 1A.

We look forward to more evidence-based recommendations quoted by the UIAA MedCom.