Ch. 25: Diuretics and Therapeutic Drug Monitoring (Vickroy) Flashcards
order diuretics in order of decreasing diuretic effect
mannitol < furosemide < chlorothiazide < spironolactone/triamterene
where are sensing mechs. for electrolyte/fluid balance?
plasma/vasculature. Not good at detecting edema in Extracellular space
therapeutic uses of diuretics
- severe edema (from liver/kidney failure, brain injury, hyperparathyroidism, pulmonary edema, CHF, DCM, etc.)
- elim. of toxic substances
edema
abnormal accum. of fluid in the interstitium
vascular changes that lead to edema form.
- inc. hydrostatic P
- dec. oncotic pressure
- inc. vascular permeability
- lymphatic blockage
composition of urine is determined by what factors?**
GFR, tubular secretion, tubular reabsorption of Na (<– diuretics act on this)
where do osmotic diuretics act?
anywhere along the tubule
inhibition of acid secretion in proximal convoluted tubule by a diuretic will:
- inc. systemic actions of some acidic drugs (i.e. antibiotics)
- dec. diuresis by thiazides and loop diuretics
diuretic
agent that increases urine production via a DIRECT ACTION on the renal epithelium (except osmotic agents)
drugs that produce diuresis by indirect/non-tubular actions
xylazine (dec. ADH release, hyperglycemia)
digoxin (inc. CO –> renal perfusion)
common feature of almost all diuretic agents
increased Na excretion
therapeutic uses of mannitol**
- acute renal failure*
- cerebral edema WITHOUT intracranial hemorrhage
- elevated intraocular P
- promote renal excretion of drugs/toxins
contraindications of mannitol**
- heart failure*
- pulmonary edema or congestion*
- intracranial hemorrhage
- severe dehydration
- renal dz
all thiazides are acidic/basic drugs with structural resemblence to ____**
acidic; sulfonamides
what is required for diuretic action of chlorothiazide?**
acid transporter
