Corticosteroid drugs are used extensively in medicine. Sensible use requires knowledge of their considerable benefits and their known side-effects.

Almost everyone has heard of steroids and quite a few people are wary of them.

Known to be highly effective for many conditions, they are also known to have potent side-effects. So much so that some sufferers avoid them when steroid medication might well give them considerable relief.

Such concerns can be alleviated by understanding what steroid drugs are and by being familiar with their current therapeutic usage.

What are Steroids?

Steroids are hormones produced in the adrenal glands (which sit on top of the kidneys) and the sex glands – testes and ovaries. All steroid hormones are made from cholesterol. They control a wide variety of bodily functions. Androgens and oestrogens control sexual development in males and females respectively and progesterone prepares the uterus for implantation of the fertilised egg and maintains pregnancy.

Uses of these hormones range from contraceptive pills, control of hormone problems, to the illicit use of anabolic steroids in sport. However the most widely used steroid hormone is cortisol.

Cortisol

Cortisol and its related hormones are manufactured in the outer part of the adrenal gland. Cortisol's major functions involve dealing with stress reactions in the body. It increases the amount of glucose in the blood so that energy is immediately available in response to danger. It does this partly by breaking down protein in muscles and, because all resources are needed to deal with the danger, it suppressesmanufacture of bone and other new tissue.

Cortisol's other main activity is to suppress inflammation. When tissue is damaged the body responds by triggering inflammation; this is a defence reaction and helps protect against infection. Healing of damaged tissue cannot take place until the inflammation mechanism has been switched off and cortisol does just this.

This is the most useful aspect of cortisol. Although inflammation is necessary for the body, its effects – redness, swelling, pain and itching can be unpleasant and even dangerous. When the anti-inflammatory effects of cortisol were first realised in the 1930's the search for drugs that could be modelled on cortisol began. Today many synthetic cortisol drugs exist.

Major Applications of Corticosteroid Drugs

• Creams and ointments: used for application to the skin in conditions such as eczema, psoriasis and some types of allergy.
• Nasal spray: sometimes prescribed for hay fever.
• Systemic medication: usually tablets or pills, and sometimes injection, used for a wide variety of problems. Many autoimmune disorders such rheumatoid arthritis, asthma and polymyalgia rheumatica are treated with steroid drugs. They are also used for preventing rejection in transplants.
• Local injection: mostly used for joint and tendon problems such as some types of back pain, shoulder injuries and tennis elbow.

Side-effects of Cortisol Medication

Prolonged use can lead to muscle wasting and bone thinning (osteoporosis) and to the development of diabetes. Glaucoma and cataracts can also occur.

Cortisol's anti-inflammatory effects can lead to exacerbation of infections and long-term use can lower immunity generally.

As with many types of medication that have been taken for a while, steroids should always be withdrawn slowly and with medical advice. This is because of the feedback effect of the the drug on the adrenal glands. With the cortisol in circulation – albeit a synthetic one - the adrenal glands slow down their own production. Rapid withdrawal of the drug will then result in insufficient cortisol for the body's needs until adrenal production builds up.

This article is for information only. If you have any health concerns you should see your doctor.

Resources

Pills, Potions, Poisons, Trevor Stone and Gail Darlington. Pub. OUP 2000

British National Formulary, British Medical Association 2004.