Adrenal cortex
Aldosterone – Mineralocorticoid
Cortisol - Glucocorticoid
DHEA, Testosterone, Estrogen and Progesterone – Sex steroids
Glucocorticoids
Glucocorticoids and BP
Glucocorticoids can cause a mild increase in blood pressure believed to be due to enhancing the vasoconstrictive effect of adrenergic stimuli on small blood vessels.
Glucocorticoids and immune cells
Glucocorticoids cause an increase in the numbers of circulating neutrophils, hemoglobin, and erythrocytes.
• Glucocorticoids cause a decrease in circulating lymphocytes (including T cells), eosinophils, basophils, monocytes, and macrophages.
• The anti-inflammatory effects of glucocorticoids are related to decreased production of prostaglandins and leukotrienes.
Glucocorticoids at cellular level
glucocorticoids inhibit the access of leukocytes to inflammatory sites, interfere with the functions of leukocytes, endothelial cells, and fibroblasts, and suppress the production and the effects of multiple factors involved in the body’s inflammatory response.
Inhibition of phospholipase A2 blocks the release of arachadonic acid, the precursor of the prostaglandins and leukotrienes from membrane bound phospholipids.
• Histamine release and kinin activity is also suppressed by glucocorticoids.
Glucocorticoids are often indicated for
• Inflammatory and allergic conditions (oral, inhaled and topical preparations) • Reactive airways disease • Allergies (rhinitis, hay fever, drug allergy) • Arthritis • Auto-immune conditions • Replacement therapy for Addison’s disease (needed for patient survival)
tachyphylaxis
Tachyphylaxis is a rapid decrease in the response to a drug over a short time period.
• Some physicians may recommend using a topical steroid for 3 consecutive days on, followed by 4 consecutive days off.
cause of tachyphylaxis is felt to be depletion of a neurotransmitter that is involved in the action of the drug. The drug causing tachyphylaxis acts indirectly by causing release of the stored neurotransmitter from the nerve terminal. After a few doses the neurotransmitter stores are depleted and no more response is obtained.
Glucocorticoids SE
Adverse effects of glucocorticoids include reduced resistance to infections, hyperglycemia and possible diabetes mellitus, severe bone loss, avascular necrosis, cataracts, myopathy, thinning of skin, diminished wound healing, easy bruising, insomnia and mental status changes.
• Increased appetite is a commonly reported side effect as is weight gain from salt and water retention
Glucocorticoids metabolism
Corticosteroids are metabolized by the liver microsomal oxidizing enzymes.
Duration of action
Duration of action
Short acting (8 - 12 hours)
• Hydrocortisone, Cortisone
Intermediate acting (18 - 36 hours)
• Prednisone, Prednisolone,
Methylprednisolone, Triamcinolone
Long acting (24 - 72+ hours)
• Paramethasone, Dexamethasone,
Betamethasone
Anti-inflammatory effect scale
Mineralocorticoid effect
abrupt weaning
Abrupt discontinuation can result in acute adrenal insufficiency syndrome (Addisonian crisis) which can be lethal.
CRH and ACTH arent around in the right amountds
Addisonian crisis
Hydrocortisone/ Cortef
Prednisone/ Deltasone
• Class: Glucocorticoid/ corticosteroid • Indications: See prior slides. Preferred
drug for reactive airways disease or moderate to severe allergic reaction. Important drug for leukemia reaction.
• MOA: Affects gene transcription to either stimulate or repress protein production.
• Char: PO. Intermediate duration of action.
• Side effects: See prior slides.
Dexamethasone/ Decadron
• Class: Fluorinated corticosteroid
• Indications: See prior slides. Extremely
potent anti-inflammatory. Also useful in IV
form for reducing intracranial pressure. • MOA: Affects gene transcription to either stimulate or repress protein production.
• Char: PO/IV/topical/inhaled. Long acting duration of action. Minimal mineralocorticoid effects.
• Side effects: See prior slides.
Triamcinolone inhaler/Azmacort
Class: Corticosteroid • Indications: Asthma, COPD. Not indicated for treating an acute asthma attack once it has already begun. • MOA: Diminishes inflammation of bronchial wall . Affects gene transcription and alters protein production. • Char: Oral inhaler
Triamcinolone inhaler/Azmacort dosing and SE
Beclomethasone/Qvar or Vancenase
Mineralocorticoids
SALT–>Sugar–> Sex
Addisons vs Conn’s and aldosterone levels
Aldosterone levels are reduced in patients with Addison’s disease and treatment is generally with a glucocorticoid that has potent mineralocorticoid properties.
Aldosterone levels are increased in patients with Conn’s syndrome and treatment is an aldosterone antagonist such as Spironolactone. Renin and aldosterone are measured, and the ratio (very low) is diagnostic
Fludrocortisone/ Florinef
• Class: Halogenated glucocorticoid/ Mineralocorticoid agonist
• Indications: Mineralocorticoid replacement for patients with Addison’s disease and in other cases of hyponatremia.
• MOA: Sodium retention. Main effect is via reduction of sodium loss to the urine at the renal tubular cells.
Char: PO. Potent mineralocorticoid effects. Long acting duration of action. Minimal glucocorticoid effects. Not indicated as an anti-inflammatory agent.
Fludrocortisone/ Florinef SE
Side effects: Salt retention, edema, hypertension, rash, nausea and vomiting, as well as the potential side effects that are attributable to glucocorticoids.