Muscle Fatigue and Carbonic Anhydrase Inhibitors

Phase 4

Completed

• Conditions: Hypoxia
• Interventions: Other: Placebo; Drug: Acetazolamide; Drug: Methazolamide

• Registration Number: NCT02758470
• Lead Sponsor: University of British Columbia

Brief Summary

The objective of this research is to assess the effects of acetazolamide and methazolamide on respiratory and limb muscle fatigue development. A fatiguing protocol will be conducted for the respiratory and plantar flexor muscles and the difference in pressure/torque produced by supramaximal nerve stimulation used to assess muscle fatigue between conditions.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2016-04-20
• Study First Submitted QC: 2016-04-28
• Study First Posted: 2016-05-02
• Study Start: 2016-11
• Primary Completion: 2017-06-30
• Study Completion: 2017-06-30
• Status Verified: 2018-09
• Last Update Submitted: 2018-09-21
• Last Update Posted: 2018-09-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 13

Inclusion Criteria

• Age: 18-40 years.
• Regularly physically active
• Male

Exclusion Criteria

• current or ex-smokers
• pulmonary function <80% of predicted
• esophageal tumour or ulcer
• have had recent (<6 months) musculoskeletal injury or any surgery to the lower leg
• have contraindications to carbonic anhydrase inhibitors (eg. severe or absolute glaucoma, adrenocortical insufficiency, hepatic insufficiency, renal insufficiency, sulfa allergy or an electrolyte imbalance such as hyperchloremic acidosis)
• are obese (BMI >30 Kg/m2)
• taking diuretics, blood thinners, or anti-platelet drugs.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Participants will take three placebo pills per day for two days prior to and a single dose on the morning of the experimental day.
Acetazolamide	Acetazolamide	Participants will be dosed 250mg acetazolamide (p.o.) three times per day for two days prior to and a single dose on the morning of the experimental day.
Methazolamide	Methazolamide	Participants will be dosed 100mg Methazolamide (p.o.) two times per day separated by a placebo dose for two days prior to and a single dose on the morning of the experimental day. The placebo dose is used to match the timing and number of pills taken between all arms of the study.

Primary Outcome Measures

Name	Time	Method
Change in plantar flexor muscle group torque generation to supramaximal tibial nerve stimulation following an isometric loading protocol	Baseline, 1, 5, 10, 20, and 30 minutes following the loading protocol for each arm of the study
Change in trans-diaphragmatic pressure generation to supramaximal phrenic nerve stimulation following inspiratory threshold loading.	Baseline, 1, 5, 10, 20, and 30 minutes following the loading protocol for each arm of the study

Secondary Outcome Measures

Name	Time	Method
Contraction time and half-relaxation time	Baseline, 1, 5, 10, 20, and 30 minutes post loading protocol
Maximal inspiratory pressure maneuvers	Baseline and immediately following loading protocol
Maximal Voluntary Contraction of the Plantar Flexor Muscle Group	Baseline and immediately following the loading protocol

Trial Locations

Locations (1)

University of British Columbia; 🇨🇦 Kelowna, British Columbia, Canada