Drugs in Sport
Following the ban of amphetamines by the IOC, many turned to OTC cold and decongestant preparations containing stimulants such as ephedrine, pseudoephedrine and phenylpropanolamine. Although less potent than amphetamines, they have a similar effect; the IOC has set cut-off values, above which they are considered to be prohibited. Urine samples are considered positive at levels of >5 micrograms/ml for ephedrine and 10 micrograms/ml for pseudoephedrine and phenylpropanolamine. Where more than one substance is present, the quantities are totalled and if they exceed 10 micograms/ml, the test is positive. Caffeine is also a sympathomimetic and its abuse is widespread, but needs to be taken in significant amounts - the threshold for caffeine is 12 micrograms/ml.
Anabolic androgenic steroids
Some athletes are putting their lives at risk by taking erythropoietin (EPO). EPO stimulates red blood cell production from the bone marrow. Synthetically prepared EPO (Eprex) is used medically to increase the haematocrit of patients with severe anaemia associated with chronic renal failure. It increases haemoglobin levels thereby increasing packed cell volume (PCV) and improving oxygenation of the blood. Eprex is being used in sport to enhance oxygen delivery to working muscles and improve athletic endurance. Abuse of EPO can increase the haematocrit in endurance athletes to very high levels. The viscosity of the blood is greatly increased which can lead to poor circulation, thrombotic lesions and myocardial infarction. It is thought that the high incidence of sudden death in some endurance athletes is due to abuse of EPO now considered to be perhaps the most deadly of the ergogenic drugs available.
PHARMACOLOGICAL, CHEMICAL AND PHYSICAL MANIPULATION
A number of drugs are subject to certain restrictions and others are prohibited by some sports authorities only.
For example, corticosteroids may be given topically (i.e. nasal, ophthalmic, aural, anal, dermatological) and via inhalation and intraarticular injection, but only with prior written notification to the appropriate authority.
Local anaesthetics are also permitted under predefined conditions, except for dental use.
Betablockers reduce anxiety and tremor and so are banned in control sports such as shooting, archery, bowls, skijumping and synchronised swimming
Many athletes use ergogenic nutritional aids to benefit performance without damaging their eligibility for competition or indeed their health. Substances promoted as beneficial include carnitine, chromium picolinate and creatine.
Many products are promoted as natural anabolic steroids, and advertised in lifestyle magazines, health food stores and more recently on the Internet. However, despite their widespread promotion, many claims are unsubstantiated and there is little evidence of benefit.
In addition, purified amino acids are also taken as a rich protein source. Some products may also be harmful. Excessive intake of protein may cause liver and kidney damage. Hypervitaminosis is not uncommon.
Creatine is currently in vogue and actively promoted by coaches, but again there is limited evidence of improved performance. Chromium picolinate is a food supplement claimed to accelerate lean body mass and concurrent loss of body fat. It is particularly popular with weightlifters and bodybuilders. Recent studies have failed to confirm any significant effects on muscular development and strength. Analogues of picolinic acid are known to affect metabolism of serotonin, dopamine and noradrenaline metabolism. Chronic renal failure has also been associated with ingestion of this supplement.
High doses of sodium bicarbonate are taken by some athletes to enhance performance. Often referred to as soda doping it involves ingestion of up to 3 mg/kg sodium bicarbonate, approximately 30 minutes before exercise. The excess alkaline load buffers the lactic acid in the blood produced from fatigued muscles. The leg muscles are most susceptible to lactic acid accumulation. Hence the popularity of soda doping with competitive cyclists and sprinters.
Ingestion of such high doses of alkaline salts is not without side effects. Fluid retention and abdominal bloating are common, as is thirst. Severe GI discomfort may occur and the excess sodium load may place undue strain on the heart. Alkalination of the urine also prolongs the halflife of prohibited substances such as amphetamines and pseudoephedrine, thereby enhancing their toxicity.
The use of performance enhancing drugs in sport contravenes the spirit of fair competition and can also be detrimental to an athlete's health. Many feel that a drug must be taken to level the playing field and for some "it is just one step from the belief that drugs can aid performance to the expectation that athletes must take drugs if they want to win medals". However, where some athletes deliberately take drugs to seek an advantage, others may inadvertently take a prohibited substance due to a lack of awareness.
Nevertheless, drug doping is here to stay and effective doping control methods must be in place, supported by education, of both athletes and health care professionals, quality research and international collaboration.