Clenbuterol

[MaNiCC]

Clenbuterol (Spirovent, Ventipulmin) is a sympathomimetic amine used by sufferers of breathing disorders as a decongestant and bronchodilator. People with chronic breathing disorders such as asthma use this as a bronchodilator to make breathing easier. It is most commonly available as the hydrochloride salt clenbuterol hydrochloride.


Systematic (IUPAC) name
Identifiers
CAS number 37148-27-9
ATC code R03AC14 R03CC13 QG02CA91
PubChem CID 2783
ChemSpider 2681

Chemical data
Formula C12H18Cl2N2O
Mol. mass 277.19
SMILES eMolecules & PubChem

Pharmacokinetic data
Bioavailability 89-98% orally
Metabolism ?
Half-life 36-39 hours
Excretion ?

Therapeutic considerations
Pregnancy cat. C
Legal status ? (UK)
Routes oral

Effects and Dosage
Clenbuterol is a non-steroidal β2 adrenergic agonist with some structural and pharmacological similarities to epinephrine and salbutamol, but its effects are more potent and longer-lasting as a stimulant and thermogenic drug. It causes an increase in aerobic capacity, central nervous system stimulation, and an increase in blood pressure and oxygen transportation. It increases the rate at which fats are metabolized, simultaneously increasing the body’s BMR. It is commonly used for smooth muscle relaxant properties. This means that it is a bronchodilator and tocolytic. It is usually used in dosages anywhere from 20-60 micrograms a day when prescribed. A dose of about 120 μg should never be exceeded in a day[citation needed]. It is also prescribed for treatment of horses; however, equestrian usage is usually the liquid form of clenbuterol. Clenbuterol is also a sympathomimetic in the peripheral nervous system.

Human use
Clenbuterol is approved for use in some countries (via prescription only) as a bronchodilator for asthma patients. Recently though, the drug has been publicized for its off-label use as a weight loss drug, similar to usage of other sympathomimetic amines such as Ephedrine. It is commonly used as a slimming aid despite lack of sufficient clinical evidence supporting such use.

Contraindications and cautions

• Hypersensitivity to the medicine
• Thyrotoxicosis
• Tachycardia
• Subaortic stenosis
• Acute myocardial infarction
• Hypertension
• Pregnancy

Overdosage
Excessive usage can cause muscle tremor, headache, dizziness and gastric irritation. Persons self-administering the drug for weight loss or to improve athletic performance have experienced nausea, vomiting, diaphoresis, palpitations, tachycardia and myocardial infarction. Abuse of the drug may be confirmed by detecting its presence in serum or urine.

Veterinary use
Clenbuterol is used worldwide for the treatment of allergic respiratory disease in horses, as it is a bronchodilator. A common trade name is Ventipulmin. It can be used both orally and intravenously. It is also a non-steroidal anabolic and metabolism accelerator, through a mechanism not well understood. Its ability to increase the muscle-to-fat body ratio makes its illegal use in livestock popular to obtain leaner meats.

Food contamination
In September 2006 over 330 people in Shanghai were reported to have been poisoned by eating pork contaminated by clenbuterol that had been fed to the animals to keep their meat lean. There are also other informal reports on localized food contamination cases by clenbuterol in the U.S., which led to setting rules that limit consumption of this medicine only to horses.

In February, 2009, at least 70 people in one Chinese province (Guangdong) suffered food poisoning after eating pig organs believed to contain clenbuterol residue. The victims complained of stomachaches and diarrhea after eating pig organs bought in local markets.

Legal status
As of fall, 2006, clenbuterol is not an ingredient of any therapeutic drug approved by the U.S. Food and Drug Administration and is now banned for IOC-tested athletes. See further at List of doping cases in sport. Polish sprint canoer Adam Seroczyński was disqualified for taking this drug after finished fourth in the K-2 1000 m event at the 2008 Summer Olympics in Beijing, and Chinese cyclist Li Fuyu tested positive for it at the Dwars Door Vlaanderen race in Belgium on March 24, 201