Response to Clenbuterol in Humans

Detectability of Clenbuterol and Physiological Response in Human Skeletal Muscle

Due to the long half-life (~36 hr) of clenbuterol, detection methods such as dried blood spots (DBS) are a potentially suitable method to easily and non-invasively detect doping misuse of this compound for several days after ingestion. If, and how long, the compound can be detected by DBS has not yet been investigated but is of interest due to its potential in doping-control. The aim is to evaluate whether abuse of clenbuterol can be detected at relevant concentration levels in samples obtained using DBS and to assess the physiological response to clenbuterol in skeletal muscle..

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Drug: Clenbuterol Oral Product; Drug: Placebo

• Study Type: Interventional
• Enrollment (Anticipated): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Copenhagen, Denmark
    • Recruiting
    • August Krogh Building

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 38 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Healthy
• Male
• 18-40 years of age
• No known contraindications for anabolic drugs (e.g. cancer)

Exclusion Criteria:

• Abnormal ECG
• Steroid abuse
• Ongoing use of prescription medication
• heavy resistance training more than 2 times weekly
• Disease deemed by the MD to infer a risk to participate in the trial

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Clenbuterol; Subjects ingest 80 micrograms of clenbuterol tablets	Drug: Clenbuterol Oral Product; Subjects ingest 4x20 microgram clenbuterol tablets
Placebo Comparator: Placebo; Subjects ingest placebo tablets	Drug: Placebo; Subjects ingest placebo tablets

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood clenbuterol concentration	Concentration of clenbuterol in dried blood spots	Before (baseline) as well as 3, 8, 24, 72, 168 and 240 hours after administration of clenbuterol

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood clenbuterol concentration	Concentration of clenbuterol in venous blood	Before (baseline) as well as 3, 8, 24, 72, 168 and 240 hours after administration of study drug
Urine clenbuterol concentration	Concentration of clenbuterol in urine	Before (baseline) as well as 3, 8, 24, 72, 168 and 240 hours after administration of study drug
Muscle strength	Maximal voluntary isometric contraction in N/m2 of the quadriceps	Before (baseline) and 2.5 hours after administration of study drug
Muscle signalling	Protein kinase A phosphorylation in vastus lateralis biopsies	Before (baseline) and 2.5 hours after administration of study drug
Plasma K+	Venous plasma K+ concentration	Before (baseline) as well as 2.5 hours after administration of study drug
Muscle mTOR signalling	mTOR phosphorylation in vastus lateralis biopsies	Before (baseline) as well as 2.5 hours after administration of study drug
Metabolic rate	Respriatory exchange ratio of oxygen and CO2	Before (baseline) as well as 2.5 hours after administration of study drug
Maximal voluntary strength	Maximal voluntary isometric muscle strength of the quadriceps	Before (baseline) and after two-week treatment of study drug
Body composition	Lean and fat mass during a DXA-scan	Before (baseline) and after two-week treatment of study drug
Aerobic capacity	Maximal oxygen uptake during maximal exercise	Before (baseline) and after two-week treatment of study drug

Collaborators and Investigators

• Sponsor: University of Copenhagen

Study record dates

Study Major Dates

• Study Start (Actual): March 11, 2019
• Primary Completion (Anticipated): March 15, 2022
• Study Completion (Anticipated): March 15, 2022

Study Registration Dates

• First Submitted: February 26, 2019
• First Submitted That Met QC Criteria: February 28, 2019
• First Posted (Actual): March 4, 2019

Study Record Updates

• Last Update Posted (Actual): May 3, 2021
• Last Update Submitted That Met QC Criteria: April 28, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Keywords: muscle strength; dried blood spots; skeletal muscle biopsies; muscle signaling
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Adrenergic Agonists; Bronchodilator Agents; Anti-Asthmatic Agents; Respiratory System Agents; Adrenergic beta-Agonists; Sympathomimetics; Clenbuterol
• Other Study ID Numbers: CLEN

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No