Clenbuterol
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| Routes of administration | oral |
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| Pharmacokinetic data | |
| Bioavailability | 89-98% orally |
| Metabolism | ? |
| Elimination half-life | 36-39 hours |
| Excretion | ? |
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| ECHA InfoCard | 100.048.499 |
| Chemical and physical data | |
| Formula | C12H18Cl2N2O |
| Molar mass | 277.19 g·mol−1 |
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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.
Effects and Dosage
Clenbuterol is a non-steroidal β2 adrenergic agonist[1] 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.[2] 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. It has just been announced that Alberto Contador tested positive for this in the 2010 Tour de France. Contador claims the test result was caused by food poisoning.[3]
Contraindications and cautions
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- Hypersensitivity to the medicine
- Thyrotoxicosis
- Tachycardia
- Subaortic stenosis
- Acute myocardial infarction
- Hypertension
- Pregnancy
Overdosage
Excessive[clarification needed] 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.[4]
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. Particularly in North America it is also known by the slang term 'bute.' 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.[5]
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.[6][7]
Legal status
As of fall, 2006, clenbuterol is not an ingredient of any therapeutic drug approved by the U.S. Food and Drug Administration[2] and is now banned for IOC-tested athletes.[8] 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, 2010.[9] In the 2010 Tour de France, Alberto Contador tested positive for clenbuterol. He claims it was due to food contamination. The case is still under review. [10]
References
- ^ A UK medical student blog, Clenbuterol is a β2 agonist, retrieved on February 8th, 2010.
- ^ a b "Clenbuterol", Daily Mail, 2009-10-01, retrieved 2010-04-07
- ^ Alberto Contador Tests Positive for Clenbuterol
- ^ R. Baselt, Disposition of Toxic Drugs and Chemicals in Man, 8th edition, Biomedical Publications, Foster City, CA, 2008, pp. 325-326.
- ^ "Pigs fed on bodybuilder steroids cause food poisoning in Shanghai". AFP. 2006-09-19. Retrieved 2006-09-19.
{{cite news}}: Cite has empty unknown parameter:|1=(help) - ^ "China: 70 ill from tainted pig organs - CNN.com". CNN. 2009-02-23. Retrieved 2010-04-30.
- ^ http://www.chinadaily.com.cn/china/2009-02/23/content_7501017.htm
- ^ Guest, Katy (2007-04-10). "Clenbuterol: The new weight-loss wonder drug gripping Planet Zero". The Independent. London. Retrieved 2007-04-10.
- ^ Radioshack suspends Li after doping positive
- ^ Alberto Contador Tests Positive for Clenbuterol
External links
- Charles F. Kearns, Kenneth H. McKeever, Karyn Malinowski, Maggie B. Struck, and Takashi Abe (2001). "Chronic administration of therapeutic levels of clenbuterol acts as a repartitioning agent". J Appl Physiol. 91 (5): 2064–2070. PMID 11641345.
{{cite journal}}: CS1 maint: multiple names: authors list (link)