S15) Steroid Pharmacology Flashcards
Identify the different layers of the adrenal cortex
Identify some different types of corticosteroids, including examples
- Glucocorticoids e.g. cortisol
- Mineralocorticoids e.g. aldosterone
- Sex steroids
Outline the HPA axis
Identify six metabolic actions of glucocorticoids
- Glycogenolysis
- Gluconeogenesis
- Hyperglycaemia
- Proteinolysis
- Lipolysis (low conc.) / lipid deposition (high conc.)
- Redistribution of fat
Identify five effects of glucocorticoid deficiency
- Hypoglycaemia
- Weight loss
- Nausea
- Hypotension
- Underweight
Identify five effects of glucocorticoid excess
- Hyperglycaemia
- Weight gain
- Increased appetite
- Hypertension
- Cushingoid
Identify four effects of mineralocorticoid deficiency
- Hyponatraemia
- Dehydration
- Hypotension
- Hyperkalaemia
Identify three effects of mineralocorticoid excess
- Hypernatraemia
- Hypertension
- Hypokalaemia
Describe the pharmacokinetics for corticosteroids
- High oral bioavailability (diffuse easily)
- Metabolised by liver, eliminated by kidney
- Hepatic and renal clearance (decreases with age)
Identify the various different routes of administration for steroid drugs and provide an example drug for each
- Intravenous e.g. methylprednisolone
- Oral e.g. prednisolone
- Inhaled e.g. beclomethasone
- Topical e.g. betamethasone
- Intra-articular e.g. triamcinolone
Describe five effects of corticosteroids on the immune system
- Inhibition of B and T cell responses
- Reduced phagocytic function
- Immunosuppression
- Reduced inflammation
- Reduced transcription of cytokines
Briefly, describe the mechanism of action of steroid hormones
What are the clinical uses of steroid drugs?
- Inflammatory disease
- Immunosuppression
- Malignancy
- Adrenal insufficiency
- Cushing’s disease diagnosis
What are the indications for corticosteroid replacement therapy?
- Deficiency
- Addison’s disease
- Adrenolectomy
Which drugs can be used for corticosteroid replacement therapy and what is their dosage?
- Hydrocortisone (cortisol) 20 - 30 mg daily
- Fludrocortisone (aldosterone) 50 - 300 μg daily
Which inflammatory diseases are treated by corticosteroids?
- Asthma
- GI disease
- Nephrotic syndrome
- Rheumatoid arthritis
- Inflammatory skin conditions
Describe the use of steroids in pregnancy
A single course of antenatal corticosteroids is offered to women who are at risk of preterm birth (24-34 weeks of gestation)
Which steroids are given to women at risk of preterm birth?
- Betamethasone 12 mg given IM in two doses
- Dexamethasone 6 mg given IM in four doses
What are the side effects of mineralocorticoids?
- Fluid retention
- Hypertension
- Hypokalaemia
What are the side effects of glucocorticoids?
- Osteoporosis
- Avascular necrosis
- Peptic ulcers
- Increased infections
- Hypertension
- Diabetes
Describe the Cushingoid fat distribution
What are the effects of corticosteroid on bone?
- Inhibition of osteoblast formation
- Increased osteoclast proliferation
- Reduced calcium absorption in gut
- Reduced sex steroid production
- Osteoporosis
How does adrenal suppression occur?
- Suppression of HPA axis occurs after 3 weeks
- Prednisolone > 20 mg will suppress HPA axis
- May persist for years, if long term treatment
What precipitates a hypo-adrenal crisis?
Abrupt withdrawal of steroids
What characterises a hypoadrenal crisis?
- Hypotension
- Hypoglycaemia
- Hyponatraemia
- Hyperkalaemia
- Severe dehydration
- Death, if untreated
