Pharmacology Flashcards
is biliary excreted so it is safe for renal impairment patients
indapamide, clopamid, Xipamide
they are Ca channel blockers and Diuretics
Indapamide, Clopamide, Xipamide
is effective in renal impairment if GFR is 20ml/min
Metolazone
short acting thiazide
cloro, Hydrocloro, Hydroflumme, bendroflumme
Long acting thiazide
Cyclo, poly, thriclormethiazide
the only thiazide drug that taken parenteral
chlorothiazide
thiazide taken?
orally
which tubule is thiazide secreted
actively secreted in PCT
antagonized with thiazide diuretic effect
Probenecid
تيته مينفعش تاخد دوا النقرس مع دوا البول
used in nephrogenic diabetes insipidus
thiazide
act as antidiuretic, it increases ADH sensitivity
Therapeutic uses of Thiazide
- Edema (renal, hepatic, cardiac)
- mild to moderate hypertension
- nephrogenic diabetes insipidus
- premenstrual tension and migraine
- Calcinuria, Ca renal stones, hypocalcemia, osteoporosis
Diuretic that is safe to renal impairment patients
indapamide, Xipamide, Chlopamide
Mechanism of Action of Thiazide
1) thiazide actively secreted in PCT ana Probenecid antagonizes its Diuretic effect
2) thiazide act in early part of DCT by inhibiting Na/Cl symporter and reabsorption (only 10% of Na)
3) excess Na reaches late part of DCT which exchanged with K and H
4) the remaining is secreted in urine with water
Results of thiazide in blood
Hypovolemia
Hyponatrimea
Hypokalemia
Hypochloremia
Hypomagnesmia
alkalosis
Hypercalcemia
what happens to thiazide effectivity when GFR less than 20ml/min
losses in diuretic effect
the effect of thiazide in nephrogenic Diabetes insipidus
act as antidiuretic by increase the sensitivity of ADH by the kidney
the effects of the thiazide
- Diuretic effect
- Antidiuretic effect in Diabetes insipidus
- Antihypertensive
- Hyperglycemia
- Hyperlipidemia
- Hyperuricemia
How thiazide make its antihypertensive effect
By its diuretic effect and direct VD
What the thiazide make in VD
- it is a K channel opener that leads to hyperpolarization
- it secretes prostaglandins. NSAIDs decrrease its effect
- it decreases Na load and edema in BV so decreases the effect of adrenaline and angiotensin
how thiazide cause hyperglycemia?
it is a K channel opener and decrease insulin secretion from panceas
How thiazide cause hyperuricemia
it competes with uric acid in secretion
how thiazide is useful in heart failure
it causes diuresis so it decreases reduces return and EDV and decreases preload
It is direct arterial VD thus reduces afterload
Adverse effects of thiazide
- Hypovolemia
- Hyponatremia
- Hypokalemia
- Hypochloremia
- Hypomagnesmia
- Alkalosis
- Hypercalcemia
- hyperglycemia
- hyperlipidemia
- hyperuricemia
- Allergy and cross allergy
- GIT irritation
- Bone marrow depression
- Fetotoxicity
Contraindications of thiazide and frusemide
- hypersensitivity
- Pregnancy
- Gout
- renal and hepatic insufficiency
- Diabetes mellitus
- with digitalis
- with steroids (more worsening of hypokalemia)
causes Hyperammonemia
Acetazolamide
Causes Fetotoxicity
Thiazide and Frusemide
because it passes placenta
Theraputic uses of Acetazolamide
- Edema
- Glucoma
- petit mal epilepsy
- alkalinize urine to dissolve urate stones
- prevention of acute mountain sickness
side effects of Acetazolamide
- weak and self limiting Diuretic
- Allergy and Cross allrgy
- metabolic acidosis
- alkaline urine leads to formation of phosphate stones
- Hepatic encephalpathy in patient with hepatic insufficinecy due to hyperammonemia
- CNS sedation and drowsiness
- Hypokalemia
Sulfonamide derivatives of loop diuretics
Frusemide, Torsemide, Bumetanide
Non- sulfonamide derivatives of loop diuretics
Ethacrynic acid, Idocrinone, Tienilic acid
absorption of loop diuretics
oral and IV
uses extensive plasma protein binding
loop diuretics
where is loop secreted
PCT
Frusemide
oral onset of action …. min and ….. h duration
IV onset of action …. min and …. h duration
30 min – 6 h
2-5 min —– 3h
needs hepatic metabolism
loop
needs hepatic metabolism
loop
Spironolactone
inhibit carbonic anhydrase enzyme
acetazolamide
frusemide
mechanism of action of Fursemide
- fursemide is actively secreted in PCT. Probenecid antgonizes its diuretic effect
- Fursemide has sulfa radical that inhibit carbonic anhydrase enzyme
- Frusemide act in the thick part of ascending loop of Henle by inhibition of symporter Na/k/Cl that disturb countercurrent multiplier system leads to excess water excretion.
- excess Na is go to DCT and some of them exchanged with K and H
- the remaining is excreted with water
effect of loop on blood
- hypovolemia
- hyponatrimia
- hypokalemia
- hypochloremia
- alkalosis
- hypomagnesmia
- hypocalcemia
effective as diuretic even if GFR less than 10 ml / min
Frusemide
has antihypertensive effect: Only by its diuretic effect. No direct VD effect.
Frusemide
actions of Frusemide
diuretic effect
antihypertensive effet
hyperglycemia
hyperlipidemia
hyperuricemia
increase protaglandins secretion
thiazide
frusemide
used in cerebral edema
Frusemide given IV