3.3 Corticosteroids & Other Hormonal Agents

3.3 Corticosteroids & Other Hormonal Agents

Hormonal agents reward precise knowledge: potency conversions, withdrawal dangers and counseling details are classic exam material.

Systemic Glucocorticoids

Glucocorticoids such as prednisolone and dexamethasone bind intracellular glucocorticoid receptors to suppress inflammatory gene transcription. Agents differ in potency, mineralocorticoid (salt-retaining) activity and duration:

Hydrocortisone's strong mineralocorticoid activity suits adrenal replacement; dexamethasone's long duration and negligible salt retention suit cerebral edema and antiemetic regimens but make HPA suppression more likely.

For once-daily dosing, give glucocorticoids in the morning to mimic the natural cortisol rhythm and limit insomnia and HPA suppression; alternate-day regimens further reduce toxicity in some chronic indications. High-dose immunosuppressive therapy contraindicates live vaccines, and blood glucose should be monitored because steroid-induced hyperglycemia can unmask or worsen diabetes.

HPA-axis suppression and tapering: systemic courses longer than about 3 weeks (or repeated short courses) suppress the hypothalamic-pituitary-adrenal (HPA) axis. Such patients must never stop abruptly — doses are tapered gradually to let endogenous cortisol recover, and patients carry a steroid card. During intercurrent illness, trauma or surgery they need stress-dose (sick-day) steroids; failure to supplement can precipitate an adrenal crisis — hypotension, hypoglycemia, hyponatremia and collapse — treated with immediate parenteral hydrocortisone and fluids.

Adverse effects and mitigation: hyperglycemia (steroid-induced diabetes), immunosuppression with masking of infection, osteoporosis (provide calcium/vitamin D and consider a bisphosphonate in at-risk patients on long-term therapy), gastrointestinal bleeding especially with concurrent non-steroidal anti-inflammatory drugs (NSAIDs) — consider proton pump inhibitor (PPI) cover — plus weight gain and Cushingoid features, hypertension, cataracts and glaucoma, mood changes or psychosis, myopathy and growth suppression in children.

Inhaled Corticosteroids

Inhaled agents (beclomethasone, budesonide, fluticasone) act locally in the airways with minimal systemic exposure at standard doses. The characteristic adverse effects are local: oral candidiasis (thrush) and dysphonia (hoarseness). Counsel patients to rinse the mouth with water and spit after each use and to use a spacer with metered-dose inhalers; high doses over long periods can still cause systemic effects.

Combined Oral Contraceptives

Combined oral contraceptives (COCs) contain an estrogen (usually ethinylestradiol) plus a progestogen and prevent ovulation by suppressing follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The estrogen component raises venous thromboembolism (VTE) risk; COCs are contraindicated with previous VTE, smoking at age 35 or over, migraine with aura, uncontrolled hypertension, and a BMI of 35 or above. Missed-pill rules (concept): one missed pill — take it as soon as remembered and continue the pack, no extra precautions; two or more missed — take the most recent pill, continue the pack, use condoms for 7 days, and consider emergency contraception if pills were missed in the first week after unprotected sex. Enzyme inducers — rifampicin, carbamazepine, phenytoin and St John's Wort — accelerate hormone metabolism and reduce efficacy, requiring alternative or additional contraception.

Non-contraceptive benefits of COCs include lighter, more regular menses and reduced dysmenorrhea, acne, and ovarian and endometrial cancer risk. Breakthrough bleeding is common in the first few cycles and does not usually signal reduced efficacy when pills are taken correctly.

Emergency Contraception

Levonorgestrel 1.5 mg (a progestogen) is licensed up to 72 hours after unprotected intercourse and works best the sooner it is taken; high body weight or BMI may reduce its efficacy. Ulipristal acetate 30 mg, a selective progesterone receptor modulator, remains effective up to 120 hours by delaying ovulation; because it competes with progestogens, patients should wait 5 days before starting or resuming hormonal contraception and use condoms meanwhile. If vomiting occurs within about 2-3 hours of either agent, the dose should be repeated. The copper intrauterine device is the most effective emergency contraception overall.

Hormone Replacement Therapy

Hormone replacement therapy (HRT) for menopausal symptoms uses estrogen alone in women without a uterus, and combined estrogen plus progestogen when the uterus is present, because unopposed estrogen drives endometrial hyperplasia. Prescribe the lowest effective dose with regular review. Oral estrogen increases VTE and stroke risk; transdermal preparations avoid first-pass hepatic effects and carry a lower VTE risk. Long-term combined HRT slightly increases breast cancer risk. HRT is most appropriate for vasomotor symptoms in women under 60 or within 10 years of menopause, where benefit generally outweighs risk; it is not started primarily for chronic disease prevention.

Desmopressin

Desmopressin is a synthetic analog of antidiuretic hormone (ADH, vasopressin) selective for V2 receptors, reducing renal free-water excretion. It treats central (cranial) diabetes insipidus, primary nocturnal enuresis, and — at higher doses — mild hemophilia A and von Willebrand disease by releasing stored factor VIII. Its defining hazard is hyponatremia and water intoxication: counsel patients to restrict fluids during treatment, monitor serum sodium (especially in the elderly and when starting), and withhold doses during illnesses causing fluid or electrolyte imbalance. Symptoms of hyponatremia — headache, nausea, confusion, seizures — warrant urgent review. Intravenous desmopressin is also used perioperatively in mild hemophilia A and von Willebrand disease; tachyphylaxis develops with repeated dosing as factor VIII stores become depleted.