Corticosteroid Therapy

  1. Mineralcorticoid (MC)
    "Na+ retaining"

    • increase Na+ = increase H2O = increase volume
    • decrease K+

    • Endogenous = Aldosterone
    • Synthetic = fludrocortisone, oral (Florinef); deoxycorticosterone, IM
  2. Glucocorticoid (GC)
    "Glucose retaining"

    • Endogenous = Cortisol (by circadian rhythm and stress
    • Regulation of fat, carbohydrate and protein metabolism
    • Naturally occurring = Hydrocortisone and Cortisone
    • Synthetics differ by duration, MC, and anti-inflammatory potency
  3. Pharmacologic Doses of GC
    Decreases Inflammation
    and Immune Response by:
    • Inhibiting macrophage accumulation in inflamed areas
    • Decreasing capillary permeability and edema formation
    • Antagonize histamine activity
    • Decrease immune globulins and passage of immune complexes through basement membrane
    • Prevent release of destructive acid hydrolases from leukocytes
  4. Glucocorticoids
    Most require hepatic conversion: prednisone metabolized into prednisolone, cortisone metabolized into hydrocortisone
  5. Glucocorticoid Equivalencies, Potencies and T 1/2
    Short Acting, T 1/2 8-12hrs: Cortisone, Hydrocortisone

    Intermediate Acting, T 1/2 18-36hrs: Prednisone:Prednisolone (1:1 equivalency), Triamcinolone, Methylprednisolone

    • Long Acting, T 1/2 36-60hrs: Dexamethasone, Betamethasone.
    • No sodium retaining properties.
    • Most postent anti-inflammatory steroids.
    • Useful for fetal organ Maturation.

    • Prednisone Equivalents
    • Hydrocortisone 20mg = Prednisone & Prednisolone 5mg, Triamcinolone & Methylpred 4mg, Dexamethasone & Betamethasone 0.75mg.
  6. Therapeutic Uses for Corticosteroids
    Primary: Addison's Disease

    Secondary: Defficiency of ACTH due to gland suppression; usually caused by overuse of exogenous GC.

    • Never curative, only decrease sx.
    • Does not affect progression of dz.
    • Use lowest dose for shortest time.
    • Taper usually not necessary if duration of use < 2wks.
    • For anti-inflammatory and immunosuppressive effects, use synthetic GC with minimal MC potency.
  7. Addison's Disease
    • General
    • Usually asymptomatic until loss of > 90% of adrenal cortex.
    • 50% usually involve clinical disorder of another hormonal system.
    • Usually minimal effect on catecholamines (medulla).

    • Common Symptoms
    • Decrease BP, decrease glucose, hyperpigmentation, vitiligo, electrolyte abnormalities

    ACTH stimulation test: abnormal response

    • Treatment
    • Physiologic doses of corticosteroids.
    • 10-20mg QD cortisol equivalent
    • GC: 2/3 AM and 1/3 PM to try to mimic circadian rhythm. Use Hydrocortisone.
    • Usually double dose during febrile illness.
    • MC: Fluodrocortisone QD

    • Monitoring Goals of Therapy
    • Normalization of BP, glucose, K+, Na+
  8. Corticosteroid Use Precautions
    Med-ID alert.

    Risk of adrenal suppression: Can last 6-12 months after long-term, high dose use.

    Infections: doses > 1 mg/kg/day of pred-equivalent.

    Pregnancy: amenorrhea with high doses; possible fetal effects.

    Pediatrics: avoid long-term use; goal of QOD dosing, growth suppression, cataracts.
  9. Corticosteroid Adverse Effects
    • General
    • Increased duration of use + increase dose = increased risk of adrenal suppression [>7.5mg prednisone for >3wks].
    • Suppression unlikely with short term use of high doses.
    • Cosyntropin test (ACTH stimulation test)

    • Measure to Avoid Suppression
    • QOD dosing.
    • Low dose, short acting, short term.
    • Use route other than systemic.

    • Immunosuppressive
    • Usually > 1mg/kg/day of prednisone-equivalent
    • Decreased inflammation by inhibiting mediators and movement of WBCs
    • Post transplant use low doses with "steroid sparing" immunosuppressive agents

    • GI
    • routine use of antacids, PPI’s and H2 antagonists not recommended for ulcer prevention
    • N/V; diarrhea/constipation; take with food

    • Cardiovascular
    • BP, lipids, fluids, electrolytes

    • CNS
    • vertigo; insomnia; depression

    • Dermatological
    • skin atrophy; ecchymosis

    • Endocrine
    • hyperglycemia

    • Musculoskeletal
    • aseptic necrosis; myalgias; weakness
    • Steroid withdrawal syndrome
    • Probably related to abrupt change in levels

    • Ophthalmic
    • ­increased IOP; cataracts [risk highest in peds and RA pts]

    • Osteoporosis [OP]
    • most serious AE!!
    • Has to do with Ca2+ balance
    • Cumulative dose of 10 gm pred-equiv
    • 50% of pts on > 7.5mg pred-equiv for > 1 yr have 4x ­increased vertebral fractures and double risk of hip fractures
    • inhibits osteoblasts; decreases intestinal absorption of Ca++
    • bisphosphonates now recommended for prevention and treatment of GC-induced OP
Author
HuskerDevil
ID
35056
Card Set
Corticosteroid Therapy
Description
Corticosteroid lecture
Updated