Clinical data | |
---|---|
Trade names | Dilaterol, Spiropent, Ventipulmin, others [1] |
AHFS/Drugs.com | International Drug Names |
Pregnancy category |
|
Routes of administration | Oral (tablets, oral solution) |
ATC code | |
Legal status | |
Legal status | |
Pharmacokinetic data | |
Bioavailability | 89–98% (orally) |
Metabolism | Hepatic (negligible) |
Elimination half-life | 36–48 hours |
Excretion | Feces and urine |
Identifiers | |
| |
CAS Number | |
PubChem CID | |
IUPHAR/BPS | |
DrugBank | |
ChemSpider | |
UNII | |
KEGG | |
ChEBI | |
ChEMBL | |
CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.048.499 |
Chemical and physical data | |
Formula | C12H18Cl2N2O |
Molar mass | 277.19 g·mol−1 |
3D model (JSmol) | |
Chirality | Racemic mixture |
| |
| |
(verify) |
Clenbuterol 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. [2]
It was patented in 1967 and came into medical use in 1977. [3]
Clenbuterol is approved for use in some countries as a bronchodilator for asthma.[ medical citation needed ]
Clenbuterol is a β2 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.[ citation needed ] It is commonly used for smooth muscle-relaxant properties as a bronchodilator and tocolytic.
It is classified by the World Anti-Doping Agency as an anabolic agent, not as a β2 agonist. [4]
Clenbuterol is prescribed for treatment of respiratory diseases for horses, and as an obstetrical aid in cattle. [5] It is illegal in some countries to use in livestock used for food. [6]
Clenbuterol can cause these side effects: [7]
Use over the recommended dose of about 120 μg can cause muscle tremors, 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. Use of the drug may be confirmed by detecting its presence in semen or urine. [8]
Clenbuterol is not an ingredient of any therapeutic drug approved by the US Food and Drug Administration [ citation needed ] and is now banned for IOC-tested athletes. [9] In the US, administration of clenbuterol to any animal that could be used as food for human consumption is banned by the FDA. [10] [11]
Although often used by bodybuilders during their "cutting" cycles, [12] the drug has been more recently[ as of? ] known to the mainstream, particularly through publicized stories of use by celebrities such as Victoria Beckham, [9] Britney Spears, and Lindsay Lohan, [13] for its off-label use as a weight-loss drug similar to usage of other sympathomimetic amines such as ephedrine, despite the lack of sufficient clinical testing either supporting or negating such use. In 2021, Odalis Santos Mena, a Mexican fitness influencer, died after suffering a cardiac arrest while being anesthetized for a procedure of miraDry, a treatment that uses thermal energy to eliminate underarm sweat glands. The coroner reported that Mena's death was attributed to a combination of Clenbuterol and anesthesia.
In a clinical study performed on young, healthy men, "Clenbuterol increased resting energy expenditure by 21% (P < 0.001), and fat oxidation by 39% (P = 0.006), whereas carbohydrate oxidation was unchanged." [14]
A common misconception about Clenbuterol is that it has anabolic properties, and can increase muscle mass when used in higher dosages. This claim has never been substantiated, and likely originated from equine research. [15] A beta-2 agonist, Clenbuterol has been found to increase short-term work rate and cardiovascular output, and consequently, its anabolic effects in horses can be attributed to exercise output and increased caloric intake. Given its ability to increase basal metabolic rate, maximum heart rate, and exercise output, Clenbuterol has ergogenic properties more closely related to ephedrine or amphetamine.
The notion that Clenbuterol is an anabolic agent likely originated from author and renowned authority on performance-enhancement Dan Duchaine. Duchaine popularized the drug in the bodybuilding community, and was the first to suggest the drug had muscle-building properties. Likewise, Duchaine erred in promoting the drug Gamma-hydroxybutyric acid (GHB) as an anabolic agent, and served time for the unlawful possession and distribution of the drug in the mid-1990s. [16] As of 2011, the World Anti-Doping Agency (WADA) listed Clenbuterol as an anabolic agent, despite the fact there is no evidence to suggest this is the case. [17]
Clenbuterol has also been used as a performance-enhancing drug. One issue is that clenbuterol is a food contaminant in some countries; doping control must distinguish between accidental and deliberate intake. [18] [19]
Clenbuterol is occasionally referred to as "bute" and this risks confusion with phenylbutazone, also called "bute". Phenylbutazone, which is a drug also used with horses, was tested for in the 2013 European meat adulteration scandal. [20]
Intended to result in leaner meat with a higher muscle-to-fat ratio, the use of clenbuterol has been banned in meat since 1991 in the US and since 1996 in the European Union. The drug is banned due to health concerns about symptoms noted in consumers. These include increased heart rate, muscular tremors, headaches, nausea, fever, and chills. In several cases in Europe, these adverse symptoms have been temporary. [21]
Clenbuterol is a growth-promoting drug in the β agonist class of compounds. It is not licensed for use in China, [22] the United States, [21] or the EU [23] for food-producing animals, but some countries have approved it for animals not used for food, and a few countries have approved it for therapeutic uses in food-producing animals.
Not just athletes are affected by contamination. In Portugal, 50 people were reported as affected by clenbuterol in liver and pork between 1998 and 2002, while in 1990, veal liver was suspected of causing clenbuterol poisoning in 22 people in France and 135 people in Spain. [24]
In September 2006, some 330 people in Shanghai suffered from food poisoning after eating clenbuterol-contaminated pork. [25]
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 stomach aches and diarrhea after eating pig organs bought in local markets. [26]
In March 2011, China's Ministry of Agriculture said the government would launch a one-year crackdown on illegal additives in pig feed, after a subsidiary of Shuanghui Group, China's largest meat producer, was exposed for using clenbuterol-contaminated pork in its meat products. A total of 72 people in central Henan Province, where Shuanghui is based, were taken into police custody for allegedly producing, selling, or using clenbuterol. [27] The situation has dramatically improved in China since September 2011, when a ban of clenbuterol was announced by China's Ministry of Agriculture. [28]
Authorities around the world appear to be issuing stricter food safety requirements, such as the Food Safety Modernization Act in the United States, Canada's revision of their import regulations, China's new food laws published since 2009, South Africa's new food law, and many more global changes and restrictions.
Clenbuterol is administered as an aerosol for the treatment of allergic respiratory disease in horses as a bronchodilator, and intravenously in cattle to relax the uterus in cows at the time of parturition, [29] specifically to facilitate exteriorisation of the uterus during Caesarian section surgery. It is licensed for obstetrical use in cattle as Planipart Solution for Injection. [30]
A bronchodilator or broncholytic is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be originating naturally within the body, or they may be medications administered for the treatment of breathing difficulties, usually in the form of inhalers. They are most useful in obstructive lung diseases, of which asthma and chronic obstructive pulmonary disease are the most common conditions. Although this remains somewhat controversial, they might be useful in bronchiolitis and bronchiectasis. They are often prescribed but of unproven significance in restrictive lung diseases.
Tetrahydrogestrinone (THG), known by the nickname The Clear, is a synthetic and orally active anabolic–androgenic steroid (AAS) which was never marketed for medical use. It was developed by Patrick Arnold and was used by a number of high-profile athletes such as Marion Jones, Barry Bonds, and Dwain Chambers.
Salbutamol, also known as albuterol and sold under the brand name Ventolin among others, is a medication that opens up the medium and large airways in the lungs. It is a short-acting β2 adrenergic receptor agonist that causes relaxation of airway smooth muscle. It is used to treat asthma, including asthma attacks and exercise-induced bronchoconstriction, as well as chronic obstructive pulmonary disease (COPD). It may also be used to treat high blood potassium levels. Salbutamol is usually used with an inhaler or nebulizer, but it is also available in a pill, liquid, and intravenous solution. Onset of action of the inhaled version is typically within 15 minutes and lasts for two to six hours.
Stanozolol, sold under many brand names, is a synthetic androgen and anabolic steroid (AAS) medication derived from dihydrotestosterone (DHT). It is used to treat hereditary angioedema. It was developed by American pharmaceutical company Winthrop Laboratories in 1962, and has been approved by the U.S. Food and Drug Administration for human use, though it is no longer marketed in the USA. It is also used in veterinary medicine. Stanozolol has mostly been discontinued, and remains available in only a few countries. It is given by mouth in humans or by injection into muscle in animals.
Beta2-adrenergic agonists, also known as adrenergic β2 receptor agonists, are a class of drugs that act on the β2 adrenergic receptor. Like other β adrenergic agonists, they cause smooth muscle relaxation. β2 adrenergic agonists' effects on smooth muscle cause dilation of bronchial passages, vasodilation in muscle and liver, relaxation of uterine muscle, and release of insulin. They are primarily used to treat asthma and other pulmonary disorders. Bronchodilators are considered an important treatment regime for Chronic obstructive pulmonary disease (COPD) and are usually used in combination with short acting medications and long acting medications in a combined inhaler.
Oxandrolone, sold under the brand names Oxandrin and Anavar, among others, is an androgen and anabolic steroid (AAS) medication which is used to help promote weight gain in various situations, to help offset protein catabolism caused by long-term corticosteroid therapy, to support recovery from severe burns, to treat bone pain associated with osteoporosis, to aid in the development of girls with Turner syndrome, and for other indications. It is taken by mouth.
Long-acting β adrenoceptor agonists (LABAs) are beta-adrenergic agonists usually prescribed for moderate-to-severe persistent asthma and chronic obstructive pulmonary disease (COPD). They are designed to reduce the need for shorter-acting β2 agonists such as salbutamol (albuterol), as they have a duration of action of approximately 12 hours in comparison with the 4-to-6-hour duration of salbutamol, making them candidates for sparing high doses of corticosteroids or treating nocturnal asthma and providing symptomatic improvement in patients with COPD. With the exception of formoterol, long-acting β2 agonists are not recommended for the treatment of acute asthma exacerbations because of their slower onset of action compared to salbutamol. Their long duration of action is due to the addition of a long, lipophilic side-chain that binds to an exosite on adrenergic receptors. This allows the active portion of the molecule to continuously bind and unbind at β2 receptors in the smooth muscle in the lungs.
Levosalbutamol, also known as levalbuterol, is a short-acting β2 adrenergic receptor agonist used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). Evidence is inconclusive regarding the efficacy of levosalbutamol versus salbutamol or salbutamol-levosalbutamol combinations, though levosalbutamol is believed to have a better safety profile due to its more selective binding to β2 receptors versus β1.
Trenbolone acetate, sold under brand names such as Finajet and Finaplix among others, is an androgen and anabolic steroid (AAS) medication which is used in veterinary medicine, specifically to increase the profitability of livestock by promoting muscle growth in cattle. It is given by injection into muscle.
Performance-enhancing substances, also known as performance-enhancing drugs (PEDs), are substances that are used to improve any form of activity performance in humans. A well-known example of cheating in sports involves doping in sport, where banned physical performance-enhancing drugs are used by athletes and bodybuilders. Athletic performance-enhancing substances are sometimes referred as ergogenic aids. Cognitive performance-enhancing drugs, commonly called nootropics, are sometimes used by students to improve academic performance. Performance-enhancing substances are also used by military personnel to enhance combat performance.
Ractopamine is an animal feed additive used to promote leanness and increase food conversion efficiency in farmed animals in several countries, but banned in others. Pharmacologically, it is a phenol-based TAAR1 agonist and β adrenoreceptor agonist that stimulates β1 and β2 adrenergic receptors. It is most commonly administered to animals for meat production as ractopamine hydrochloride. It is the active ingredient in products marketed in the US as Paylean for swine, Optaflexx for cattle, and Topmax for turkeys. It was developed by Elanco Animal Health, a division of Eli Lilly and Company.
Selective androgen receptor modulators (SARMs) are a class of drugs that selectively activate the androgen receptor in specific tissues, promoting muscle and bone growth while having less effect on male reproductive tissues like the prostate gland.
Higenamine (norcoclaurine) is a chemical compound found in a variety of plants including Nandina domestica (fruit), Aconitum carmichaelii (root), Asarum heterotropioides, Galium divaricatum, Annona squamosa, and Nelumbo nucifera.
Enobosarm, also formerly known as ostarine and by the developmental code names GTx-024, MK-2866, and S-22, is a selective androgen receptor modulator (SARM) which is under development for the treatment of androgen receptor-positive breast cancer in women and for improvement of body composition in people taking GLP-1 receptor agonists like semaglutide. It was also under development for a variety of other indications, including treatment of cachexia, Duchenne muscular dystrophy, muscle atrophy or sarcopenia, and stress urinary incontinence, but development for all other uses has been discontinued. Enobosarm was evaluated for the treatment of muscle wasting related to cancer in late-stage clinical trials, and the drug improved lean body mass in these trials, but it was not effective in improving muscle strength. As a result, enobosarm was not approved and development for this use was terminated. Enobosarm is taken by mouth.
In the United States the National Collegiate Athletic Association (NCAA), has since the 1970s been patrolling the usage of illegal drugs and substances for student-athletes attending universities and colleges. In 1999, NCAA Drug Committee published a list containing substances banned for the usage to student-athletes. Year after year it is updated and given to those students participating in college sports. If any student is caught taking any of the substances, they are subjected to suspension or even banned from participating in NCAA sports and possibly attending the university.
Antibiotic use in livestock is the use of antibiotics for any purpose in the husbandry of livestock, which includes treatment when ill (therapeutic), treatment of a group of animals when at least one is diagnosed with clinical infection (metaphylaxis), and preventative treatment (prophylaxis). Antibiotics are an important tool to treat animal as well as human disease, safeguard animal health and welfare, and support food safety. However, used irresponsibly, this may lead to antibiotic resistance which may impact human, animal and environmental health.
Ligandrol, also known by the developmental code names VK5211 and LGD-4033, is a selective androgen receptor modulator (SARM) which is under development for the treatment of muscle atrophy in people with hip fracture. It was also under development for the treatment of cachexia, hypogonadism, and osteoporosis, but development for these indications was discontinued. Ligandrol has been reported to dose-dependently improve lean body mass and muscle strength in preliminary clinical trials, but is still being developed and has not been approved for medical use. The drug is taken by mouth.
Boldenone undecylenate, or boldenone undecenoate, sold under the brand names Equipoise and Parenabol among others, is an androgen and anabolic steroid (AAS) medication which is used in veterinary medicine, mainly in horses. It was formerly used in humans as well. It is given by injection into muscle.
Roxadustat, sold under the brand name Evrenzo, is an anti-anemia medication. Roxadustat is a HIF prolyl-hydroxylase inhibitor that increases endogenous production of erythropoietin and stimulates production of hemoglobin and red blood cells. It was investigated in clinical trials for the treatment of anemia caused by chronic kidney disease (CKD). It is taken by mouth. The drug was developed by FibroGen, in partnership with AstraZeneca.