Athletes normally use drugs while training and during an event to give themselves an unfair advantage over the other competitors. Drugs can be used during training to allow the person to train for longer, build muscle faster and to quicken the recovery after training, to allow them to train sooner than from the time taken to recover naturally.
The world anti-doping agency (WADA) is the head of controlling the use of drugs within major sports, the Olympics, NBA etc.i WADA have banned many substances from use within sports for several reasons, the main reason to protect the athlete and their health as not everyone who takes then performance enhancers does it of their own free will. Other reasons include the prevention of aggressive behavior because some steroids can promote aggression and in a contact sport this could lead to fatal injuries to the opponent. Also the effect performance enhancers has on fair play, taking a substance that gives you an unfair advantage is pure and simple cheating.
The use of drugs as an aid in sports dates back to ancient times, where mushrooms and herbs were used by the Greeks and Romans to enhance performance. In the 19th century these mushrooms and herbs were substituted for alcohol, opium and caffeine. In the present day there is a much larger cocktail of drugs used including; anabolic agents, ?2-agonists, diuretics, stimulants, narcotics and beta blockers to mention a few.
The aim of this dissertation is to look into the classes of drugs used in the sporting world, how they affect the body, how they work in the body on a cellular level, how athletes are tested for drugs and the side effects of short and long term use.
Examples of drugs used
Androgenic anabolic steroids are synthetic forms of the male hormone Testosterone, in sports the more common steroids are Stanozolol (aka Stromba) and Nandrolone (aka Deca-Durabolin). WADA (world anti-doping agency) holds a list of all banned steroids from the major sporting organizations some of the oral administered steroids that are banned include Anadrol (oxymetholone), Oxandrin (oxandrolone) and Dianabol (methandrostenolone). Banned injectable steroids include Durabolin (nandrolone phenpropionate), Depo-Testosterone (testosterone cypionate), Equipoise (boldenone undecylenate).
Stromba can come in the form of a 50mg/ml injection or a 5mg tablet where Nandrolone comes in a 2ml vial with a dosage of 100mg/ml, the effective dose is 250 1500 mg per week. These drugs when taken increase protein synthesis and enhance muscle development, when used in the medical world these drugs can decrease the itching of chronic biliary obstruction and they are used in the therapy of some aplastic anaemias. Steroids can also be used to compensate for people who can produce testosterone or can produce enough of it for their body to function normally, this is a symptom of 47, XXY males (Klinefelters syndrome).ii In sports the enhanced muscle development side of steroids is more important. It is more likely to observe this type of drug use in athletes who will be required to use a lot of strength, ie weight lifters, shot putters, discus throwers etc in the Olympics. The use of these drugs may also be observed in sports such as rugby and baseball.
Normally ?2-agonists are used in the treatment of asthma by acting as a bronchodilator, which requires stimulation of ?2 adrenoceptors. Athletes exploit the ability of these drugs to dilate the airways and use ?2-agonists in order to gain advantage over the competition by being able to take deeper breaths than normal. This was mostly seen in swimming events where the athlete could stay under water longer and reduce resistance while swimming. Some ?2-agonists are still permitted for use by the International Olympic Charter (IOC)iii, the permited drugs are salbutamol, terbutaline, formoterol and salmeterol. However if an athlete is to take one of these drugs they must wait until the initial effects of the drug have passed before competing. This drug is normally taken orally through use of an inhaler.
Narcotics are one of the earliest drugs used in medicine for pain relief; they work by acting on the brain to reduce the amount of pain felt. This is useful to athletes who maybe injured to allow themselves to force their bodies back into training. This is very risky, as forcing training upon an injured body can lead to further injury.iv Narcotics can be administered through many different methods, depending on what drug it is. Cocaine is normally inhaled through the nose, heroin is normally injected into a vein and morphine can be administered through IV drip or taken in the form of a tablet. The benefit of this class of drug is it allows the athlete to push themselves further, through what is known as the pain threshold. The pain threshold is like a wall that athletes will hit while training vigorously for extended periods of time, this wall is often difficult to overcome and the use of narcotics aids in this battle. This class of drug doesnt just include illegal drugs such as heroin or cocaine but also includes morphine, and although mild, codeine.
Diuretics which include Frusimide, chlorothiazide and hydrochlorothiazide come in a tablet form and can prevent the reabsorption of water from the kidneys, this is used in the medical world as treatment for heart failure and hypertension, and it can also be used in lower concentrations to reduce blood pressure. Diuretics are controlled in sports due to their ability to remove water from the body; this type of drug is mostly beneficial to athletes who are trying to make a weight class, ie boxing. If an athlete is meant to be in a middle class weight group and looses water to put him in a light weight class it gives him an unfair advantage over who he may be fighting. Diuretics can also be used to mask the effect anabolic steroids have on the body, as these steroids can cause the body to retain water. Diuretics have also been taken to try and cover drug usage when tests are carried out, as diuretics can control the excretion of water from the body they have been taken to try and dilute the concentration of other drugs in urine.v
Beta-blockers are a primary therapeutic use in the fight against cardiovascular disease, but it was also found during treatment that these medicines stopped muscle tremors.vi This is of benefit to the sports of professional archery or shooting in the pentathlon and can also be used in snooker. The down side to this is the disadvantage it holds in activates that exert the body like long distance running, so to combat the use of beta-blocker so the officials of the pentathlon held the long distance running and shooting on the same day. However the athletes then started using beta-blockers with a shorter half life.
The drugs used in sport all work to the same purpose which is to enhance ones performance in a specific event through non-natural means. Although all the drugs described work towards the same goal, they each work differently in the body on a cellular receptor level. In this section I will describe and discuss the pharmacokinetics and pharmacodynamics of some of these drugs. I will also look at the desired effects on the body and the unwanted effects as well as metabolism of drugs.
Pharmacokinetics deals with the half life of drugs in the body, the metabolism and excretion of drugs from the body. Pharmacodynamics is how the drug produces its response, the receptors involved and where they may be located in the cell and what organs are affected by the drug in question.
The body is a very effective tool when it comes to transforming active chemicals into inactive ones. This process is done through the use of enzymes normally produced by the cells of the liver, but some other cells throughout the body are also used for metabolism. In relation to this topic metabolism is simple changes to an active chemical or drug into a safe metabolite which can then be excreted from the body.vii
However metabolism does not always work this way, sometimes an active compound can be metabolized into another active compound which the same pharmacological effect with higher or lower potency or a completely different pharmacological effect. An active compound may also be changed into a toxic metabolite or an inactive drug can be activated.
Drugs can be eliminated from the body through many means. The compounds can be passes through urine from the kidneys or in faeces from the rectum. They can also be passed from the bodys salivary glands as saliva, from the sweat glands, the pulmonary epithelium as exhaled gasses and from mammary glands in the form of mammary milk.
The half life of a drug is the time taken for the concentration of a drug in your system to half; the half life varies from drug to drug. Normally a drug is taken at regular intervals to keep its concentration in the therapeutic level. Athletes however may only take one dose of the drug for their upcoming event.
Anabolic steroids bind to androgen receptors found in the prostate, skeletal muscle, the liver and the CNS. The highest expression level was observed in the prostate, adrenal gland and epididermis which were determined by real-time PCR reactions.viii The androgen receptors are located in the cytoplasm of a cell, which is why steroids have to be soluble compounds. Once testosterone or DHT binds to a receptor it is translocated to the nucleus. Androgen receptors are directly linked to the regulation of gene transcription, when a receptor is stimulated by testosterone it produces primary male characteristics by activating hormones in the wolffian duct. Wolffian ducts are embryonic structures which form the male internal genitalia.ix
The secondary male characteristics such as hair follicles are a response to DHT binding to the androgen receptor; DHT is produced when 5-alpha-reductase acts on testosterone. One of the more common side effects of this drug is the inhibition of your own hormones. If more of a hormone is introduced into your body it will cause your body to react and produce less of the hormone. Other side effects include not being able to perform sexually, steroids can lead to an increase in LDLs (bad cholesterol), an increase in estrogen has also been observed which can lead to the development of breast tissue in men and steroids can also have a damaging effect on the liver.
?2-agonists as the name suggest work on ?2 adrenoceptors which are located on the cell membrane. When a ?2-agonist binds to a ?2 adrenoceptor it causes smooth muscle relaxation which in asthma sufferers dilates the airways and helps them to breathe normally, in athletes this allows them to take deeper breaths and inhale more oxygen which increases stamina and reduces fatigue. The major side effect from ?2-agonists is cardiac arrhythmia, this is due to an increased myocardial oxygen demand, ?2-agonists can also lead to angina in patients with coronary artery disease and tremors have also been observed.
Narcotics are classed as opioids, which are any drug that produces morphine-like-effects, and bind to opioid receptors. Opioid recrptors are linked through G-proteins to inhibition of adenylate cyclase and facilitate the opening of Potassium channels which causes hyperpolarisation. This binding also inhibits the opening of calcium channels which inhibits transmitter release. The side effects of these drugs include respiratory depression, euphoria, sedation and dependence. There are three subcategories of opioid receptors, , ? and ? receptors. Pure opioid drugs have more of an affinity for receptors; this binding is what produces the euphoric effect of opioid drugs.xThe opioid receptors can be found both presynaptically and postsynaptically depending on the cell type. Receptors are mostly presynaptic in the periaqueductal grey region of the brain. These receptors can also be found in layers of the cerebral cortex and the intestinal tract.
Diuretics are divided into two categories; loop diuretics which are of the most powerful and distal tubule diuretics. Normally less than 1% of sodium that is taken into the body is excreted but the use of loop diuretics causes fifteen to twenty percent of filtered sodium to be excreted with copious amounts of urine. Loop diuretics work by inhibiting sodium, potassium and chloride co-transporters in the thick ascending loop and increase potassium and calcium loss.xi The unwanted effects of this include dehydration and hypokalaemia (defined as a potassium level of less than 3.5 mEq/l).
Beta-blockers attach to ? adrenoceptors on cells of the heart and produce no response in the cell. The body normally responds to stress by releasing lots of adrenaline which activates the bodies fight or flight response which is normally useful in the cases of being chased by a bear. Some athletes however have to keep their cool and take beta-blockers to stop this response from occurring.xii Athletes that require a steady hand for accurate aim in archery may be persuaded to take these. The undesired effects of this type of drug is it disallows your heart rate to increase, so if beta-blockers are taken before a race blood wont circulate oxygen around the body fast enough to maintain a fast pace.
From my research I can understand why some athletes may take performance enhancing drugs but I am not certain the short term gain outweighs the long term loss. Boxers who are a tiny bit heavy and have to go into a tougher weight class are understandably scared; they will be among the lightest in their class going up against bigger guys, where if they use diuretics and drop some water they become the bigger guys in a lower weight class. For some athletes they may be getting on in their career and want to end it with a win so they cheat in order to finish their career on a high.
Athletes at the start of their career are out of their minds, to put it politely, to use these drugs because they have a whole career ahead of them to work on weakness in a natural way and better themselves each year until they achieve their victory. Is it not better to work hard at something and reap more self satisfaction knowing that you have trained hard and achieved your goal of your own doing without damaging your body, than to win a hollow victory through the use of drugs and then be disgraced when tests come back positive for drug use.
All in all I think drugs should stay where they belong, in the hospitals where they are of most benefit to society.
i World Anti-Doping Agency (WADA) constitutive instrument of foundation, 1999, lausanne (www.wada-ama.org)
ii Hormonal studies in klinefelters syndrome august 1974, C. Wang, H.W.G. Baker, D.M. DEKrester, B, Hudson
iii International Olympic Charter against doping in sports, medical commission, IOC 1990
iv Drugs in sport fourth edition, 2005, David R. Mottram
v The influence of diuretics on excretion and metabolism of doping agents, 1986, Delbeke FT, Debackere M
vi Heart failure reviews, pharmacokinetics and Pharmacodynamics of beta-blockers in heart failure volume 9/issue 2 April 2004 , Springer Netherlands
vii Drugs and the human body fifth edition 1996, Ken Liska
viii The androgen receptor: a mediator of diverse response, 1996, Keller ET, Ershler WB, Chang C [pubmed]
ix Regulation of wolffian duct development, 2007, Hannema SE, Hughes IA [pubmed]
x A primer of drug action, A comprehensive guide to actions, uses and side effects of psychoactive drugs eleventh edition, 2007, Robert M. Julian, Clair D. Advokat, Joseph E. Comaty
xi Rang and Dales pharmacology sixth edition, 2007, H.P. Rang, M. Maureen Dale, James M. Ritter
xii Pharmacology fifth edition, 2003, H.P. Rang, M.M. Dale, J.M. Ritter, P.K. Moore