The generic term for the group of hormones produced by the ADRENAL GLANDS, with a profound eﬀect on mineral and glucose metabolism.
Many modiﬁcations have been devised of the basic steroid molecule in an attempt to keep useful therapeutic eﬀects and minimise unwanted side-eﬀects. The main corticosteroid hormones currently available are CORTISONE, HYDROCORTISONE, PREDNISONE, PREDNISOLONE, methyl prednisolone, triamcinolone, dexamethasone, betamethasone, paramethasone and deﬂazacort.
They are used clinically in three quite distinct circumstances. First they constitute replacement therapy where a patient is unable to produce their own steroids – for example, in adrenocortical insuﬃciency or hypopituitarism. In this situation the dose is physiological – namely, the equivalent of the normal adrenal output under similar circumstances – and is not associated with any side-eﬀects. Secondly, steroids are used to depress activity of the adrenal cortex in conditions where this is abnormally high or where the adrenal cortex is producing abnormal hormones, as occurs in some hirsute women.
The third application for corticosteroids is in suppressing the manifestations of disease in a wide variety of inﬂammatory and allergic conditions, and in reducing antibody production in a number of AUTOIMMUNE DISORDERS. The inﬂammatory reaction is normally part of the body’s defence mechanism and is to be encouraged rather than inhibited. However, in the case of those diseases in which the body’s reaction is disproportionate to the oﬀending agent, such that it causes unpleasant symptoms or frank illness, the steroid hormones can inhibit this undesirable response. Although the underlying condition is not cured as a result, it may resolve spontaneously. When corticosteroids are used for their anti-inﬂammatory properties, the dose is pharmacological; that is, higher – often much higher – than the normal physiological requirement. Indeed, the necessary dose may exceed the normal maximum output of the healthy adrenal gland, which is about 250–300 mg cortisol per day. When doses of this order are used there are inevitable risks and side-eﬀects: a drug-induced CUSHING’S SYNDROME will result.
Corticosteroid treatment of short duration, as in angioneurotic OEDEMA of the larynx or other allergic crises, may at the same time be life-saving and without signiﬁcant risk (see URTICARIA). Prolonged therapy of such connective-tissue disorders, such as POLYARTERITIS NODOSA with its attendant hazards, is generally accepted because there are no other agents of therapeutic value. Similarly the absence of alternative medical treatment for such conditions as autoimmune haemolytic ANAEMIA establishes steroid therapy as the treatment of choice which few would dispute. The use of steroids in such chronic conditions as RHEUMATOID ARTHRITIS, ASTHMA and DERMATITIS needs careful assessment and monitoring.
Although there is a risk of ill-eﬀects, these should be set against the misery and danger of unrelieved chronic asthma or the incapacity, frustration and psychological trauma of rheumatoid arthritis. Patients should carry cards giving details of their dosage and possible complications.
The incidence and severity of side-eﬀects are related to the dose and duration of treatment. Prolonged daily treatment with 15 mg of prednisolone, or more, will cause hypercortisonism; less than 10 mg prednisolone a day may be tolerated by most patients indeﬁnitely. Inhaled steroids rarely produce any ill-eﬀect apart from a propensity to oral thrush (CANDIDA infection) unless given in excessive doses.
General side-eﬀects may include weight gain, fat distribution of the cushingoid type, ACNE and HIRSUTISM, AMENORRHOEA, striae and increased bruising tendency. The more serious complications which can occur during long-term treatment include HYPERTENSION, oedema, DIABETES MELLITUS, psychosis, infection, DYSPEPSIA and peptic ulceration, gastrointestinal haemorrhage, adrenal suppression, osteoporosis (see BONE, DISORDERS OF), myopathy (see MUSCLES, DISORDERS OF), sodium retention and potassium depletion.