Also called corticosteroids or glucocorticoids, these compounds are extremely important for modulating the function of the immune system as well as many other systems. They are products of the adrenal glands, the small endocrine glands located on the upper pole of each kidney. They share a common origin from cholesterol with the androgens (male sex hormones) as well as the estrogens and progestogens (the female sex hormones) and some others that help retain salt. The corticosteroid that the body utilizes for physiological actions is called hydrocortisone. Its main effects are in modulating almost every arm of the immune system and the inflammatory cascade. It also has an important effect on retaining salt by the kidneys. When the adrenal glands fail (usually called “Addison’s disease), the importance of the latter function becomes evident; the patient will find it hard to maintain the blood pressure.
In therapeutics, the corticosteroids are synthesized in labs and factories andmost are available for ingestion. Examples are prednisone, prednisolone and methyl prednisolone. For administration of large doses and in emergency settings, preparations are available for parenteral administration. Upon administration by all routes, they are effectively absorbed but act with a delay of several hours. This is because they are first taken up by the cytoplasmic receptors, transported to the nucleus and then a new protein is transcribed (ordered) and it is this protein that carries out the steroid’s actions. In chronic inflammatory diseases such as asthma, rheumatoid arthritis or ulcerative colitis, oral steroids are used for terminating a flare-up, the so-called “burst steroid therapy”. This is when a large dose is given, usually once each morning for a few days only. Rarely, steroid doses are given daily but then as quickly as possible, tapered to alternate days, at the minimum required doses. The reason for this caution is the occurrence of side effects from long term use.
The side effects are the limiting factors in the chronic use of steroids. The commonest of these are weight gain, “mooning of face”, thinning of skin and bones, aggravation of hypertension and peptic ulcer. The most dreaded side effect is that of pituitary-adrenal axis suppression, as the administration of steroids from outside virtually shuts down patient’s own adrenal gland. This will leave the patient without the support of the immediate steroid surge in the event of an emergency. One way to avoid using steroids internally for long periods is to formulate them for local use; examples are creams and ointments for skin, inhalers for nose and lungs and enema for use in the rectum. While this strategy dramatically reduces the systemic side effects of steroids, local side effects still occur and, especially in high doses, some systemic effects also appear. The appearance of glaucoma or cataract by the long-term use of steroid asthma inhalers or nasal inhalers is examples of the former. One dreaded complication in children comes from using steroids for very long periods, even in relatively small doses; this is retardation of growth. Switching to nonsteroidal agents or at least reducing the dose of steroids drastically, are strategies used to reduce such complications.
This article was submitted by P.K. Raghuprasad M.D. If the reader wants more information or has questions, please direct it to Dr. Raghu’s email address: firstname.lastname@example.org
Disclaimer: The facts presented in this article and the views expressed are solely those of the author(s) and do not necessarily reflect the views of the Board of Directors or other members of West Texas Physicians Alliance.