Uses of Corticosteroids

USES

A. Replacement Therapy

1. Acute Adrenal Insufficiency

It is an emergency. Hydrocortisone or dexamethasone are given i.v., first as a bolus injection and then as infusion, along with isotonic saline and glucose solution. Amount of fluid infused i.v. is guided by monitoring central venous pressure, because these patients have reduced capacity to excrete water load. Shortterm i.v. infusion of a vasopressor (dopamine) may be needed.

2. Chronic Adrenal Insufficiency (Addison’s Disease)

Hydrocortisone given orally is the most commonly used drug along with adequate salt and water allowance. Some patients in addition need a mineralocorticoid: fludrocortisone is added.

3. Congenital Adrenal Hyperplasia (Adrenogenital Syndrome)

It is a familial disorder due to genetic deficiency of steroidogenic enzymes, mostly 21hydroxylase. As a result the synthesis of hydrocortisone and aldosterone suffers. There is compensatory increase in ACTH secretion— adrenals hypertrophy; enzyme deficiency being only partial in most cases, normal amounts of gluco and mineralocorticoids are produced along with excessive amounts of weak androgens → virilization/precocious sexual development. If deficiency is severe, salt wasting also occurs.

Treatment is to give hydrocortisone 0.6 mg/ kg daily in divided doses round the clock to maintain feed back suppression of pituitary. If salt wasting persists—fludrocortisone 10–20 μg/ kg daily may be added.

B. Pharmacotherapy

(for nonendocrine diseases)

Systemic as well as topical corticosteroids have one of the widest spectrum of medicinal uses for their anti-inflammatory and immunosuppressive properties. Steroids are powerful drugs. They have the potential to cause dramatic improvement in many severe diseases as well as produce equally dramatic adverse effects if not properly used. The use in nonendocrine diseases is empirical and palliative, but may be life saving. The following general principles must be observed.

 i.            A single dose (even excessive) is not harmful: can be used to tide over mortal crisis, even when benefit is not certain.

ii.    Short courses (even high dose) are not likely to be harmful in the absence of contraindications; starting doses can be high in severe illness.

iii.      Longterm use is potentially hazardous: keep the duration of treatment and dose to minimum, which is found by trial and error; even partial relief may have to be tolerated.

iv.            Initial dose depends on severity of the disease; start with a high dose in severe illness—reduce gradually as symptoms subside, while in mild cases start with the lowest dose and titrate upwards to find the correct dose.

v.       No abrupt withdrawal after a corticoid has been given for > 2 to 3 weeks: may precipitate adrenal insufficiency.

 vi.            Infection, severe trauma or any stress during corticoid therapy—increase the dose.

vii.            Use local therapy (cutaneous, inhaled, intranasal, etc) wherever possible.

1. Arthritides

Rheumatoid arthritis: Corticosteroids are indicated only in severe cases as adjuvants to NSAIDs when distress and disability persists despite other measures, or when there are systemic manifestations (see Ch. No. 15).

Osteoarthritis: It is generally treated with analgesics and NSAIDs: systemic use of corticoids is rare. Intraarticular injection of a steroid may be used to control an acute exacerbation. Injections may be repeated 2–3 times a year, but have the potential to cause joint destruction.

Rheumatic fever: Corticoids are used only in severe cases with carditis and CHF, because they afford faster relief than aspirin, or in patients not responding to aspirin. Aspirin is given in addition and is continued after corticoids have been withdrawn.

Gout: Corticoids (short course) should only be used in acute gouty arthritis when NSAIDs have failed to afford relief and colchicine is not tolerated. Intraarticular injection of a soluble glucocorticoid is preferable to systemic therapy.

Though they are uricosuric—use in chronic gout is not recommended.

2. Collagen Diseases

Most cases of systemic lupus erythematosus, polyarteritis nodosa, dermatomyositis, nephrotic syndrome, glomerulonephritis and related diseases need corticoids. They may be life saving. Therapy is generally started with high doses which are tapered to maintenance dose when remission occurs.

3. Severe Allergic Reactions

Corticoids may be used for short periods in anaphylaxis, angioneurotic edema, urticaria and serum sickness. However, even i.v. injection of steroid takes 1–2 hours to act and is not a substitute for Adr (which acts immediately) in anaphylactic shock and angioedema of larynx. Topical use is made in allergic conjunctivitis and rhinitis.

4. Autoimmune Diseases

Autoimmune haemolytic anaemia, idiopathic thrombocytopenic purpura, active chronic hepatitis respond to corticoids. Prednisolone 1–2 mg/kg/day is given till remission, followed by gradual withdrawal or lowdose maintenance depending on the response. Remission may also be induced in severe cases of myasthenia gravis, in which their use is adjunctive to neostigmine.

5. Bronchial Asthma

Early institution of inhaled glucocorticoid therapy is now recommended in most cases needing inhaled β₂ agonists almost daily (see Ch. No. 16). Systemic corticosteroids are used only for:

• Status asthmaticus: give i.v. glucocorticoid; withdraw when emergency is over.

• Actue asthma exacerbation: shortcourse of high dose oral corticoid, followed by gradual withdrawal.

• Severe chronic asthma not controlled by inhaled steroids and bronchodilators: add low dose prednisolone daily or on alternate days.

6. Other Lung Diseases

Corticosteroids benefit aspiration pneumonia and pulmonary edema from drowning. Given during late pregnancy, corticoids accelerate lung maturation and surfactant production in the foetus and prevent respiratory distress syndrome at birth. Two doses of betamethasone 12 mg i.m. at 24 hour interval may be administered to the mother if premature delivery is contemplated.

7. Infective Diseases

Administered under effective chemotherapeutic cover, corticosteroids are indicated only in serious infective diseases to tideover crisis or to prevent complications. They are indicated in conditions like severe forms of tuberculosis, severe lepra reaction, certain forms of bacterial meningitis and Pneumocystis carinii pneumonia with hypoxia in AIDS patients.

8. Eye Diseases

Corticoids are used in a large number of inflammatory ocular diseases—may prevent blindness. Topical instillation as eye drops or ointment is effective in diseases of the anterior chamber—allergic conjunctivitis, iritis, iridocyclitis, keratitis, etc. Ordinarily, steroids should not be used in infective conditions. But if inflammation is severe, they may be applied in conjunction with an effective antibiotic. Steroids are contraindicated in herpes simplex keratitis and in ocular injuries. Posterior segment afflictions like retinitis, optic neuritis, uveitis require systemic steroid therapy. Retrobulbar injection is occasionally given to avoid systemic side effects.