Steroids

Question 1

Dexamethasone (Decadron)

Answer 1

long acting corticosteroid
25x glucocorticoid effects compared to cortisol with minimal mineralcorticoid effects

Uses;

• antiemetic
• anti-inflammatory (local and systemic)
• brain tumor (tx edema around tumor)
• post-intubation edema
• prevent RDS in premi
• croup
• aspiration pneumonitis (controversial)

MOA;

• suppresses the normal immune response; inhibits the product of pro-inflammatory cells
• MOA r/t to antiemetic prorates is unknown but thought to be r/t decreases prostaglandins, enhanced endorphins and improved appetite

Dose;
-ani-emetic 4 - 10 mg IV
-cerebral edema; loading dose 10 mg
maintenance infusion 4mg q 6hrs over 6 days
*IV bolus over 5 -10 min r/t perianal discomfort

Pharmacokinetics;

• PO peak; 1 -2 hrs
• IM peak 8 hrs
• E1/2 life2 - 3.5 hrs
• Bio half life; 36 - 54 hrs
• DOA; 72 hrs

metabolized by the liver and excreted in the urine and feces

Side Effects;
-hyperglycemia 
-insomnia
-nervousness
-tremor
-increased appetitie
-HPA axis suppression
-electrolyte abnormalities 
increased risk infection 
-osteoporosis
-PUD
-skeletal muscle weakness  
-CBC changes
-abnormal growth
-decreases anticoagulant effects   
[[short term use; less than 7 days these effects are unlikely]] 

Contraindicated;

• hypersensitivity
• untreated infection

Caution;

• DM
• hypothyroidism
• HTN
• cirrhosis
• CHF
• Ulcerative Colitis
• thromboembolic disorders

Question 2

Methylprednisolone

Answer 2

synthetic corticosteroid
5x glucocorticoid effects compared to cortisol

Uses;
replacement therapy for deficient states
-immunosuppressant effects
-Secondary tx for anaphylaxis when bronchospasm or shock occurs
-pre-op prophylaxis in asthmatic pt
-pre-op replacement for aren-cortical suppression
-Epidural steroid injection
-post- transplant immunosuppression to prevent rejection
-aspiration pneumonitis (controversial)

MOA;

• suppresses the normal immune response; inhibits the product of pro-inflammatory cells
• modulation of carbs, proteins, and lipid metabolism and changes inn fluid and electrolyte homeostasis [[causes a catabolic state]]

Dose;
IV; 10 - 250 mg q 4 -24 hr
-epidural steroid injection 40 - 80 mg with epi

Pharmacokinetics;

• crosses the placenta
• E1/2t; 2 - 4 hrs
• E1/2 life ; 3 - 3.5 hrs
• DOA 3 - 36 hrs

metabolized by the liver and excreted by the kidney

Side effects;
-Hyperglycemia
-Fluid and electrolyte imbalance (K, Na)
-HTN (from fluid retention)
-immunosuppression (risk of infection/ delays wound healing) 
-osteoporosis 
-PUD
-increased appetite 
-psych symptoms 
-protein catabolism 
(- nitrogen balacne) 

Contraindications;

• systemic infection
• hypersensitivity

Caution;
-DM

Question 3

Hydrocortisone (cortisol)

Answer 3

Corticosteroid
Endogenous hormone 1:1 (glucocorticoid: mineralocorticoid)
Average day release 10 – 20 mg/day
Extreme stress 50 – 150 mg/day

Uses;
-Replacement therapy

MOA;

• suppresses the normal immune response; inhibits the product of pro-inflammatory cells
• modulation of carbs, proteins, and lipid metabolism and changes inn fluid and electrolyte homeostasis [[causes a catabolic state]]
• Passively diffuses through lipid bilayer; Binds to mineralocorticoid & glucocorticoid receptors in cytoplasm
• Altering DNA transcription and alters protein synthesis
• increases Anti-inflammatory proteins
• decrease Inflammation proteins
• COX blocker

Dose;
Anaphylaxis; corticosteroid 250 mg
Acute adrenal insufficiency; cortisol 100 mg q8 hours (more than physiologic)
Chronic adrenal insufficiency; cortisone PO 25 mg QAM and 12.5 mg Q-afternoon

Many regimens: follow institution guidelines for steroid replacement therapy
Minor: preop dose + 25 mg IV
Moderate: preop dose + 50 - 75 mg IV
Major: preop dose + 100 - 150 mg IV q 8 hr

Pharmacokinetics;

• Peak effect; 6 hrs
• E½t: 1.5 - 3 hr
• DOA; 8 - 12 hrs
• Pb: 90%
• Liver metabolism 70%
• Active metabolite  17-hydroxycorticosteroids & 17-ketosteroids
• 30% excreted unchanged urine

Side Effects;

• Hyperglycemia
• HYPO K+
• Insomnia, nervousness,
• increased appetite, indigestion
• Na+ & fluid retention
• HTN (increase Renin secretion)
• Immunosuppression
• Addison’s Crisis with sudden withdrawal
• CUSHING’s SYNDROME; Fat redistribution
• Muscle & bone wasting, delayed wound healing

Contraindicated

• Hypersensitivity
• Caution in diabetes
• Caution in active untreated infections