Clenbuterol (also commonly known as Clenbuterol hydrochloride) in the prescription drug market is used for the treatment of asthma as it is a bronchodilator. Beyond its application in the treatment of breathing disorders it is also commonly used as a thermogenic that is for burning fat. This drug belongs to the class of compounds which are known as sympathomimetics. The other drugs of the sympathomimetics category include caffeine, ephedrine, albuterol, amphetamines, cocaine etc. Most of the drugs of this category are related in terms of their mechanism of action through similar pathways. The drug was originally developed as a veterinary drug for the treatment of respiratory problems in horses and other animals in the year 1970. This drug is marketed with different names such as Dilaterol, Spiropent, and Ventipulmin but is mostly referred to as “clen”.
The stimulants belonging to the sympathomimetic category act on the sympathomimetic nervous system. It is in the nervous system that the stimulants interact with adrenoreceptors which are present in different tissues and cell types. There are two types of adrenoreceptors in the body that is alpha and beta receptors which are further divided into two types and nine subtypes. Different stimulants act on different adrenoreceptors such as some may act on beta-1 or beta-2 adrenoreceptors and so on. Some stimulants may act on just one subtype and some may be capable on acting on multiple subtypes such as ephedrine. It is because of this that the drugs are different from each other even though they belong to the same class.
There are number of side effects related to the use of clenbuterol like effects on cholesterol and blood pressure. These side effects are common to the stimulants class of drugs. However there are some unique side effects reported for Clenbuterol which include muscle cramping. This side effect is also reported for patients using Albuterol which is similar to Clenbuterol and is referred to as close sister compound of Clen. The muscle cramping occurs due to depletion of the amino acid taurine both in the muscle tissue and in serum blood plasma. Like magnesium, potassium and sodium, taurine is also very important for contraction and relaxation of the muscles. These electrolytes help in the regulation of bioelectrical nerve impulses and thus control the signals which govern the muscle movements. When taurine is depleted intense and painful muscle contractions occur which lead to cramps.
The negative impact of the drug on the heart and cardiovascular system include cardiac hypertrophy, enlargement of ventricles, irregular heart rate, and cardiac necrosis. These effects on cardiovascular system are observed because Clenbuterol increases the amount of collagen which is an inelastic material and thus leads to increase in the size of the heart muscle. Collagen reduces the amount of pumping of the blood and thus output is decreased and it also interferes with the signals which are sent to the heart muscles. The drug also induces heart cell degeneration.
Other common side effects of Clenbuterol include insomnia, sweating, perspiration, tremors or shaky hands, high blood pressure, palpitations, dry mouth, nervousness, headaches, anxiety, nausea and vomiting. Patients also witness allergic reactions such as hives and rashes. Apart from this the drug also leads to increase in the bone fragility which leads to increased risk of bone fractures.