The effects of sleep medication on mountaineers

A team of researchers from Grenoble University Hospital has studied the impact of sleep medication on the vigilance and motor agility of mountaineers when awoken in the middle of the night at high altitude. The results highlight a reduction in physical and mental ability that could potentially increase the risk of accidents.

MAY 2018

Impact des somnifères sur les alpinistes

  • Project partner: EXALT, Centre for Altitude Expertise (HP2 laboratory, Grenoble-Alpes University and Grenoble-Alpes University Hospital)
  • Country: France
  • Project type: Gaining knowledge
  • Budget: €5,000 in 2016 and €5,000 in 2017

In 2013, an initial study conducted at the Cosmiques and Goûter mountain refuges, at the foot of the normal routes up Mont Blanc, indicated that the mountaineering community consumes significant quantities of medication. Around 39% of the 430 samples collected revealed that medication had been taken, primarily diuretics to combat altitude sickness (acetazolamide or “Diamox”, 20.6%) and sleeping pills (12.9%).

While sleep medication allows climbers to fall asleep faster and achieve restorative sleep, we do not know their effect on the vigilance and motor skills of mountaineers a few hours after they are taken, if for example they awake at night to scale Mont Blanc.

Researchers from the EXALT association recruited 22 subjects to conduct physical and cognitive tests during the summer of 2017. These tests were performed first at low altitude, in Grenoble, and later at the Aiguille du Midi, at 3,800 m, to assess the effects of sleep medication at high altitude. After ingesting a sleeping pill or a placebo, the subjects slept for four hours. They were then awoken at 1:30 am and subjected to a battery of tests under medical supervision.

Impact des somnifères sur les alpinistes

The results highlighted that taking 10mg of Zolpidem (sleep medication) at bed time altered a mountaineer’s balance four hours later to an extent liable to impact their abilities and safety.

In addition, it was demonstrated that taking a sleeping pill increases reaction times and the number of errors made in simple cognitive tests. It appears that the alteration of cognitive performance is linked to an overall alteration of brain function. The results suggest that taking sleep medication in the evening before waking up in the middle of the night may increase the risk of accidents. This new knowledge warrants wider circulation among all mountaineers, be they amateur or professional.

Samuel Vergès, Centre for Altitude Expertise:

Samuel Vergès

“Along the normal routes of Mont Blanc, a sleeping pill taken in the evening may still have an effect when the mountaineers begins his/her ascent, due to the early hour of departure. Our team therefore tested the effects on functional capacities of a sleeping tablet taken at bed time in the event of an early rise. Our research indicates that such taking such a drug has a substantial effect on the balance and cognitive functions liable to alter the abilities and safety of a climber equipped with crampons and holding ice axes, in a demanding environment.”

Uploaded in May 2018


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