Chapter 3 Flashcards
(33 cards)
Corticosteroids Naturally occurring:
( ممكن انه ينعطى او يكون بالجسم ) ومن الشغلات الي بتكون بالجسم:
وبتم افرازهن من ال cortex بال adrenal gland
a. Glucocorticoids
b. Mineralocorticoids
a. Glucocorticoids
l) Cortisol (hydrocortisone)
2) Corticosterone
3) Cortisone
b. Mineralocorticoids
l) Aldosterone
2) Desoxycorticosterone
Synthetic preparations of Glucocorticoids:
بتصنف بحسب ال action يعني قديش بظل يشتغل بالدم
- Short acting: (12 hours or less):
a) Cortisol (hydrocortisone).
b) cortisone.
- short acting, synthetic glucocorticoids
Synthetic preparations of Glucocorticoids:
- Intermediate-acting (12-24 hours)
a) Prednisone
b) Prednisolone
c) Methylprednisolone
d) Triamcinolone
- intermediate acting, synthetic glucocorticoids
Synthetic preparations of Glucocorticoids:
- long-acting (More than 48 hours)
a) Betamethasone
e) Paramethasone
b) Dexamethasone
c) Flumethasone
- long action, synthetic glucocorticoids
Pharmacokinetics:
مهم حفظ.
- 90% of glucocorticoid protein bound - increase half life.
- is a lipid soluble but absorption rate is low because it is protein bound.
- Because it is lipid-soluble, it enters the cell easily. - Active transport of bound steroid into cell
- corticosteroid binding globulin - delivers drug to cell.
- Albumin binding restricts volume of distributio.
Pharmacodynamic:
- Mechanism 1:
Inhibit phospholipase A2 -> inhibit arachidonic acid (AA) formation
Inhibit prostaglandin -> antinflammatory
Pharmacodynamic:
- Mechanism 2 :
- Binding of glucocorticoid to receptor in cytoplasm and transport to nuclease.
- complex binding to regulatable gene, causes in increase DNA transcription.
- proteins may be produced (depending on specific genes activated).
Two receptors in mechanisms:
- Phospholipase A2.
- Transcription factor.
Inhibition phospholipase A2, lead to
- inhibition Thromboxane - antiplatelets effect
Pharmacological effect :
- antinflammatory
- antiplatelate aggregation
- vasoconstriction
- decrease nociceptors - analgesia
Adverse effect:
- Ulcer
- Bleeding
- Immunosuppression
Systemic Effects of Glucocorticoids:
1. Central Nervous System:
- stimulate appetite.
- Euphoria and behavioral changes, Lower Seizure Threshold.
Systemic Effects of Glucocorticoids:
2. Gastrointestinal tract
- Decreased calcium and iron absorption.
- facilitated fat absorption.
- increase acid, pepsin, trypsin (increase digestive)
- elevate liver enzyme - Alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase (GGT)
Systemic Effects of Glucocorticoids:
3. metabolic action
- increase live glycogen store.
- promote gluconeogenesis - formation sugar from non-carbohydrate source.
- blood sugar level rise.
- increase lipolysis
Systemic Effects of Glucocorticoids:
4. Hematopeoietic system - bone marrow
- involution of lymphoid tissue.
- decrease lymphocytes, monocyte, eosinophil.
- increase pseudooeutrophilia, platelets, RBC / pseudoneutrophilia: increase count of neutrophil but prevent migrate to tissue.
- decrease clotting time and phagocyte.
- increase haemoglobin synthesis.
Systemic Effects of Glucocorticoids:
5. Cardiovascular system
- increase epinephrine.
- positive inotropic effect (increase heart rate).
- increase blood pressure.
Systemic Effects of Glucocorticoids:
6. Kidney
- Increased reabsorption of water, sodium, chloride
- Increased excretion of potassium, calcium
- Increased extracellular fluid
Systemic Effects of Glucocorticoids:
7. Bone
- Inhibition of collagen synthesis by fibroblasts
- Antagonism of Vitamin D
Systemic Effects of Glucocorticoids:
8. Reproductive Tract
- Parturition induced during the latter part of pregnancy in ruminants and horses.
- Teratogenesis during early pregnancy.
Systemic Effects of Glucocorticoids:
9. Skeletal muscle
Weakness due to decrease calcium level
Septic shock cause vasodilation, treatment:
Treat with corticosteroids.
- increase epinephrine.
- reduce inflammatory mediator.
Immunosuppressive effects:
- Decrease T lymphocytes in blood thus reducing cell- mediated immunity.
- Inhibits hypersensitivity reactions and cell- mediated immunologic functions.
- Inhibit complement activation and action.
- Inhibit T and B lymphocyte function and decrease circulating lymphocytes and monocytes.
- Reduce amount of antigen released by grafted tissue.
- Delay revascularization.
- Antiallergic effects (associated with antiinflammatory and immunosupressive effects).
