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Comparison of Temazepam and Acetazolamide to Treat Difficulty Sleeping at High Altitude

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01519544
Recruitment Status : Completed
First Posted : January 27, 2012
Last Update Posted : April 23, 2015
Information provided by (Responsible Party):
N. Stuart Harris MD MFA, Massachusetts General Hospital

Brief Summary:
More than 70% of visitors to high altitude suffer poor sleep. The present study seeks to answer the question: Which medication is associated with better sleep at high altitude: temazepam or acetazolamide? The investigators hypothesis is that one medication will be associated with higher subjective sleep scores than the other. The study will compare the sleep quality of 100 subjects as they take either temazepam or acetazolamide during a visit to high altitude.

Condition or disease Intervention/treatment Phase
High-altitude Sleep Disturbance Drug: Temazepam Drug: Acetazolamide Not Applicable

Detailed Description:

Difficulty sleeping is very common with acute high altitude exposure. Sleep disturbances were reported by more than 70% of participants in acute mountain sickness pharmacologic treatment trials. Difficulty sleeping is one of the primary complaints of visitors to high altitude and some authors consider difficulty sleeping to be nearly universal at high altitudes. Acetazolamide, temazepam, zolpidem and zaleplon are all effective and safe in treating the acute insomnia of high altitude. No head-to-head trials have been performed to determine the best drug class for treatment of high altitude sleep disturbances. The purpose of this study is to compare temazepam and acetazolamide in the treatment of high altitude sleep disturbances. Such knowledge will benefit the hundreds of thousands of visitors to areas of high altitude throughout the world.

The study will be a convenience sample of 100 trekkers in Manang, Nepal (elevation 11,500 feet). The study will only enroll trekkers who have gained more than 200 meters (650 feet) over the preceding 24 hours. Subject enrollment will take place from March 1, 2012, through May 30, 2012. One hundred subjects will be enrolled.

All subjects will complete the study in Manang, Nepal. Once an individual decides to enroll in the study, they will be instructed on the risks of the study and informed consent will be obtained. Eligibility to participate will be verified.

Each subject will be randomly assigned to take 125 mg of acetazolamide or 7.5 mg of temazepam by mouth immediately prior to going to bed. Each subject will only take one dose of the medication as part of the trial. Subjects will wear a pulse oximeter and an actigraph to bed. An actigraph is an accelerometer that is worn like a wrist watch. Actigraphs can sense and record movement and for this reason are often used in sleep studies to help measure sleep duration and quality.

Study participants will keep a sleep log and will be asked to complete a Groningen Sleep Quality Questionnaire Survey and Lake Louise Acute Mountain Sickness questionnaire. Subjects will also complete a Stanford Sleepiness Scale every hour for eight hours.

Through both objective and subjective measurement of sleep quality, this study is designed to determine which medication is associated with improved sleep at high altitude.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 34 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: Treatment of High-altitude Sleep Disturbance: A Double-blind Comparison of Temazepam Versus Acetazolamide.
Study Start Date : March 2012
Actual Primary Completion Date : July 2012
Actual Study Completion Date : March 2015

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Temazepam
50 subjects are instructed to take 7.5mg temazepam by mouth prior to going to sleep for one night only.
Drug: Temazepam
Temazepam 7.5mg capsule to be taken by mouth at bedtime for one night only.
Other Name: Restoril

Active Comparator: Acetazolamide
50 subjects are instructed to take 125mg of acetazolamide by mouth prior to going to sleep one night only.
Drug: Acetazolamide
Take Acetazolamide 125mg tablet by mouth at bedtime for one night only.
Other Name: Diamox

Primary Outcome Measures :
  1. Global assessment of sleep quality using a 100mm visual analog scale [ Time Frame: 1 day ]
    The morning after taking the study medication, subjects will be asked: How would you rate last night's sleep quality? They will mark their answer on a 100mm visual analog scale with 0mm representing 'worst night of sleep ever' and 100mm representing 'best night of sleep ever'.

  2. The Groningen Sleep Quality Questionnaire survey [ Time Frame: 1 day ]
    The Groningen Sleep Quality Questionnaire survey includes fifteen questions that describe sleep onset, sleep quality, awakenings, sleep duration, and wake up quality. Survey is completed by the subject.

Secondary Outcome Measures :
  1. Sleep Onset Latency [ Time Frame: 1 day ]
    The amount of time it takes the subject to fall asleep. Reported by the subject.

  2. Total Sleep Duration [ Time Frame: 1 day ]
    The total amount of time that the subject slept. Recorded by the subject.

  3. Time in Bed [ Time Frame: 1 day ]
    The amount of time the subject spent in bed. Recorded by the subject.

  4. Number of Awakenings [ Time Frame: 1 day ]
    The number of times the subject woke up from sleep. Recorded by the subject.

  5. Number of Awakenings to Urinate [ Time Frame: 1 day ]
    Number of time the subject woke up from sleep to use the restroom. Recorded by the subject.

  6. Wake Time After Sleep Onset [ Time Frame: 1 day ]
    Amount of time the subject spent awake after falling asleep. Recorded by the subject.

  7. Terminal Wakefulness [ Time Frame: 1 day ]
    The amount of time the subject spends in bed after waking up for the last time. Reported by the subject.

  8. Global assessment of sleep depth [ Time Frame: 1 day ]
    Subjects will be asked to rate the depth of sleep on a 100mm visual analog scales.

  9. Global assessment of drowsiness [ Time Frame: 1 day ]
    Subjects will be asked to assess their daytime drowsiness on a 100mm visual analog scale.

  10. Stanford Sleepiness Scale scores [ Time Frame: 1 day ]
    During each of the eight hours after waking up, subjects will be asked to complete a Stanford Sleepiness Scale to measure how sleepy they are.

  11. Lake Louis Acute Mountain Sickness delta score [ Time Frame: 1 day ]
    Subjects will be asked to fill out a Lake Louise Acute Mountain Sickness score at the beginning and end of study participation. The Lake Louise Acute Mountain Sickness score reflects on the severity of Acute Mountain Sickness being experienced by the subject. Scores consistent moderate or severe Acute Mountain Sickness will exclude subjects from participation in the study.

  12. Mean O2 Saturation [ Time Frame: 1 day ]
    Study subjects will wear a pulse oximeter during the night that will record their oxygen saturation.

  13. Proportion of time in periodic breathing [ Time Frame: 1 day ]
    Visitors to high altitude experience periodic breathing (alternating periods of increased and decreased respiratory rate) as the human body adjusts to the hypoxemia of high altitude. Both temazepam and acetazolamide have been shown to improve periodic breathing. Subjects will wear pulse oximeters. Data from the pulse oximeters will be used to calculate the amount of time that subjects spend in periodic breathing.

  14. Number of desaturation events per hour [ Time Frame: 1 day ]
    Due to the periodic breathing that occurs at high altitude, there are frequent oxygen desaturations during sleep. Subjects will wear a pulse oximeter to determine how many time they experience a decline in their oxygen saturation during the night.

  15. Number of awakenings per hour [ Time Frame: 1 day ]
    Subjects will wear an actigraph while they sleep. Actigraphs are small wristwatch-like devices that measure subtle movements while a subject is asleep. These movements are used to objectively describe awake and asleep periods.

  16. Sleep Efficiency [ Time Frame: 1 day ]
    Subjects will wear an actigraph when they sleep. Actigraphs are small wristwatch-like devices that measure the subtle movements of a subject during the night and help objectively determine awake and asleep periods. Using data from the actigraph, one may calculate what percent of the night the subject was asleep (sleep efficiency).

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Trekkers on the Annapurna circuit
  • Must be in the process of ascent (> 200 meters over the previous 24 hours)
  • Must be willing to stay 2 nights in Manang, Nepal
  • Healthy adults, age 18-65
  • Self-report of new difficulty sleeping over the previous two days

Exclusion Criteria:

  • Recent (< 2 weeks) high altitude exposure (higher than 11, 500 feet or 3500 meters)
  • Current acute illness
  • Moderate to Severe Acute Mountain Sickness (Lake Louise AMS score > 4)
  • High Altitude Cerebral Edema
  • High Altitude Pulmonary Edema
  • Any pre-existing sleep disorders or sleep related condition including obstructive sleep apnea, morbid obesity (BMI > 40), restless leg syndrome, etc.
  • Any lung disease or condition affecting the lungs, including chronic obstructive pulmonary disease, asthma, cystic fibrosis, etc.
  • Congestive heart failure, pulmonary hypertension, or cardiomyopathy
  • Current oxygen use
  • Kidney disease
  • Liver disease
  • Pregnancy or breast feeding
  • Seizure disorder or other neurologic disorder
  • Glaucoma
  • Sulfa allergy
  • Acetazolamide allergy
  • Benzodiazepine allergy
  • Temazepam allergy
  • Currently on acetazolamide
  • Currently taking any benzodiazepines
  • Current medical treatment with any of the following: antidepressants, neuroleptics, anxiolytics, H1 antihistamines, barbiturates or hypnotics (including benzodiazepines or any other sleep aids).
  • Major psychiatric diagnosis (depression, anxiety, schizophrenia)
  • Recreational drug use
  • Caffeine con¬sumption > 3 cups of coffee/day
  • Alcohol consumption > 1 drink/day
  • Mental Retardation or Developmental Disabilities
  • Inability to provide informed consent

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01519544

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Himalayan Rescue Location clinic in Manang
Manang, District of Manang, Nepal, 33500
Sponsors and Collaborators
Massachusetts General Hospital
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Principal Investigator: Norman S Harris, MD, MFA Massachusetts General Hospital
Auerbach, Paul S. Wilderness Medicine, 5th ed. Mosby, Phidelphia. Pages 4-8. 2007.
Bradwell AR, Coote JH, Smith P, et al. (1987) The effect of temazepam and Diamox on nocturnal hypoxia at altitude [abstract]. In: Sutton J.R., Houston C.S., Coates G., ed. Hypoxia and Cold, New York: Praeger; 1987: P543.
Hackett P. and Olez O. (1992). The Lake Louise consensus on the definition and qualification of altitude illness. In: J. Sutton, G. Coates and C. Houston (Eds) Hypoxia and mountain medicine. Queen City Press, Burlington, 1992: 327-330.
Mulder-Hajonides van der Meulen WREH, Wijnberg J.R., Hollander J.J., De Diana I.P.F. and van den Hoofdakker R.H. (1980) Measurement of subjective sleep quality. Eur. Sleep Res. Soc. Abstr. 5:98.
Meijman T.F., Thunnissen M.J., de Vries-Griever A.G.H. (1990) The after-effects of a prolonged period of day-sleep on subjective sleep quality. Work Stress. 4:65-70.
Kryger M.H., Roth T. and Dement W.C. (2011). Chapters 143 and 147. Principles and Practice of Sleep Medicine, 5th ed. Saunders, St. Louis, 2011.

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Responsible Party: N. Stuart Harris MD MFA, Director, MGH Wilderness Medicine Fellowship; Chief, Division of Wilderness Medicine, Department of Emergency Medicine, Massachusetts General Hospital; Assistant Professor of Surgery, Harvard Medical School, Massachusetts General Hospital Identifier: NCT01519544    
Other Study ID Numbers: 2012P000017
First Posted: January 27, 2012    Key Record Dates
Last Update Posted: April 23, 2015
Last Verified: April 2015
Keywords provided by N. Stuart Harris MD MFA, Massachusetts General Hospital:
High Altitude
High-altitude Sleep Disturbance
Acute Mountain Sickness
Difficulty Sleeping at High Altitude
Periodic Breathing
Groningen Sleep Quality Questionnaire survey
Stanford Sleepiness Scale
Lake Louise Acute Mountain Sickness Score
Additional relevant MeSH terms:
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Altitude Sickness
Sleep Wake Disorders
Nervous System Diseases
Mental Disorders
Respiration Disorders
Respiratory Tract Diseases
Carbonic Anhydrase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Natriuretic Agents
Physiological Effects of Drugs
Hypnotics and Sedatives
Central Nervous System Depressants
Anti-Anxiety Agents
Tranquilizing Agents
Psychotropic Drugs
GABA Modulators
GABA Agents
Neurotransmitter Agents