Diuretics and Antidiuretics Flashcards
Carbonic anhydrase (CAse) inhibitors
Acetazolamide
Acetazolamide
Inhibits carbonic anhydrase in PCT
Cause alkaline diuresis
Hpehloei etaoli aidosis
Ciliary body of eye
Secrets HCO3- into the aqueous humor (CAse is required)
Choroid plexus
Secrets HCO3- into the CSF (CAse is required)
Carbonic anhydrase (CAse) inhibitors Indications
Glaucoma
** dorzolamide & brinzolamide **
Acute mountain sickness
Urinary alkalization
Metabolic alkalosis
Carbonic anhydrase (CAse) inhibitors Adverse Effects
Hyperchloremic metabolic acidosis
- Renal stones
- Hypokalemia
Hypersensitivity reactions
Carbonic anhydrase (CAse) inhibitors Contraindications
*hepatic cirrhosis
Loop diuretics (High ceiling diuretics)
Furosemide
Furosemide
inhibit Na+/K+/2Cl- co-transport in the thick ascending limb of loop of Henle ->
abolition of lumen positive potential
Most efficacious diuretics
*** increase renal blood flow (due to PG synthesis)
↑ loss of Mg++ & Ca++
Loop diuretics (High ceiling diuretics) Indications
Acute pulmonary edema
Edema due to acute left ventricular failure
Acute renal failure
Hypercalcemia
Anion overdose
Loop diuretics (High ceiling diuretics) Side Effects
Hypokalemic metabolic alkalosis
Ototoxicity
Hyperuricemia
Hypocalcemia
Hypomagnesemia
Allergic reactions (skin rash, eosinophilia, interstitial nephritis)
Other toxicities
- severe dehydration
- hyponatremia
Thiazides
Hydrochlorothiazide, chlorothiazide
Hydrochlorothiazide, chlorothiazide
Block Na+/Cl- co-transport in DCT
↑ Ca++ reabsorption
↑ uric acid level
Thiazides Indications
Hypertension
Heart failure
Nephrolithiasis (due to idiopathic hypercalciuria)
Nephrogenic diabetes insipidus
Thiazides Adverse Effects
Hypokalemic metabolic alkalosis
Hyperuricemia
Impaired carbohydrate tolerance- *hyperglycemia
*Hyperlipidemia
Allergic reactions- photosensitivity, hemolytic anemia, thrombocytopenia 7.
weakness, fatigability & parasthesia
Potassium sparing diuretics
Antagonize the effects of aldosterone at distal and cortical collecting tubule
antagonism: spironolactone & eplerenone
inhibits Na influx: amiloride & triamterene
Spironolactone
synthetic steroid
competitive antagonist of aldostereone
Eplerenone
spironolactone analog with greater selectivity for the aldosterone receptor
** used for treatment of HTN
Triamterene and amiloride
Do not block aldosterone receptor instead they directly interfere with Na+ entry
Indications of K+ sparing diuretics
- Mineralocorticoid (aldosterone) excess
- Hypertension (along with thiazides)
- Edematous conditions (heart failure, hepatic cirrhosis)
Side effects of K+ sparing diuretics
- Hyperkalemia
- Metabolic acidosis
- Gynecomastia (only with spironolactone)
Osmotic diuretics
mannitol
mannitol
Proximal tubule and descending limb of loop of Henle
NOT ABSORBED ORALLY
↓ intracranial pressure
Osmotic diuretics Indications
reduce intracranial (in cerebral edema) & intraocular pressure (in glaucoma)
increase urine volume
Osmotic diuretics Side effects
can complicate heart failure, may produce pulmonary edema (mannitol is contraindicated in pulmonary edema and edema due to heart failure)
dehydration and hypernatremia
Vasopressin
luminal water channel, AQP2
ADH agonists
Desmopressin (V2 selective), Vasopressin, Terlipressin, Lypressin
(PRESSIN)
ADH antagonists
Conivaptan, Tolvaptan Demeclocycline & Lithium
V1a receptors
blood vessels
vasoconstrictor
GPCR -> IP3/DAG
V2 receptors
GPCR -> adenylyl cyclase
vasodilator
↑water permeability in distal kidney tubules
___ receptors are more sensitive to ADH
V2
vasopressin on platelet agregation
release of coagulation factor VIII & von Willebrand factor (V2 action)
V1 receptor uses
Bleeding esophageal varices- vasopressin
V2 receptor uses
Diabetes insipidus (DI)
Hemophilia, von Willebrand disease
Vasopressin antagonists (DLC)
demeclocyline
lithium
conivaptan
in hyponatremia, used to treat:
liver cirrhosis
SIADH
