The LCR advises 5 mg/kg daily divided in two doses; the ITM advises 125 to selleck chemical 250 mg twice daily (bid), independent of body weight. Although the standard preventive dose is 250 mg bid, there is limited data to support the efficacy of 125 mg bid.7–12 Many experts nowadays recommend

this lower dose as it empirically appears to be as effective with fewer side effects. Even in the recently published American College of Chest Physicians (ACCP) classification scheme for grading evidence and recommendations in clinical guidelines of the Wilderness Medical Society a preventive dose of 125 mg bid is advised.13 The standard recommendation for treatment is 250 mg bid.10–12 All travelers who plan to climb above 3,000 m within a few days are advised to bring acetazolamide along and to start taking it as soon as they experience the first

symptoms of AMS. The recommended dose is the same as for preventive use. In addition, an analgesic like paracetamol (LCR and ITM) and/or anti-nausea medication (ITM) is advised to relieve symptoms. The main objective of this study was to investigate the incidence and predictors of AMS in travelers who consulted a pre-travel clinic and to study the compliance with the advices concerning prevention and treatment. This retrospective observational study was Nivolumab chemical structure implemented in the travel clinics of four local public health services in the Netherlands (GGD Hart voor Brabant, Urease GGD West Brabant, GGD Brabant Zuid-Oost, and GGD Zeeland) and the ITM in Belgium. All travelers >16 years in the Netherlands and >18 years in the ITM consulting for pre-travel advice between March 1 and August 31, 2008 and planning to stay overnight above 2,000 m were included. All these clients received oral and written advices about AMS. Permission was asked to send a questionnaire after their return, which no one refused. A questionnaire was sent 1 week after return, and a reminder was sent 2 weeks later. As there was no existing questionnaire available, we developed our own and tested it on intelligibility in a pilot study. Collected data

included gender, age, destination, maximum overnight altitude, current health problems or medication intake, number of nights spent between 1,500 and 2,500 m before climbing above 2,500 m, number of days climbing from 2,500 m until maximum overnight altitude, whether acetazolamide was brought along, taken as prevention or used as treatment, and history of previous AMS. We asked details about complaints on the first days above 2,000 m and about the treatment if they had complaints. Only questionnaires of travelers who had slept at or above 2,500 m were used for analysis, as the preventive advice only applies to these situations. For the purpose of this analysis, we used the Lake Louise consensus on the definition of altitude illness.