In Response to Reduced Acetazolamide Dose for AMS by McIntosh et al

In Reply to Dr Bennett

“…Currently, there are over 500 described shark species. 1 Many of them (eg, requiem sharks of the genus Carcharhinus) are difficult to identify to the species level, even for trained professionals. This is especially true when there is only limited information available, as is usually the case after a bite.…”

“…In the study by van Patot et al, participants lived between 1400 and 1600 m and were taken from 2000 m to 4300 m by car over a 2-h period. 2 In contrast, McIntosh et al recorded altitudes of residence of 632 §804 m and travel altitudes from 745 §803 m. 1 The high-risk period will have been the drive or flight, likely to Lukla airport (2860 m) from Kathmandu (1400 m), which represents a significantly different ascent profile when compared with the study by van Patot et al The exact nature of this risk is not known because participants followed their own itinerary. This leads me to offer 2 cautions: 1) the recommendation of 62.5 mg twice daily acetazolamide as prophylaxis should be delayed until a consensus has been reached on its efficacy in reducing incidence and severity of AMS based on studies of suitable sample size; and 2) future studies should ensure they are powered from studies engaging in similar ascent profiles where applicable.…”

“…Referring to the recently published RADICAL trial, 1 the authors have alluded to the possibility their sample was statistically underpowered. As a result of both study design and increased education, I feel that this is certainly the case.…”

“…We thank Dr. Bennett 1 for his interest in our publication of the RADICAL (Reduced Acetazolamide Dosing in Countering Altitude Illness) trial. 2 This trial was the first to examine a dose of acetazolamide lower than the 125 mg twice daily typically recommended to prevent acute mountain sickness (AMS).…”