# Diuretics --- **Diuretics** are a substance that increase the rate of [[bladder|urination]]. Some work by *exceeding* the ability of the renal tubule to perform [[tubular reabsorption|reabsorption]]. For example, high [[blood glucose]] acts as a diuretic because it carries water with it as it is excreted. Some work by *inhibiting* [[sodium|Na+]] from being [[tubular reabsorption|reabsorbed]]. For example, [[caffeine]] works this way. Another diacritic, [[alcohol]], inhibits the release of [[antidiuretic hormone|ADH]]. ## Loop Diuretics loop diuretics are super common (furosemide) often indicated [[fluid volume excess|hypervolemia]] especially works by blocking the reabsorption of sodium causes an increased loss in K+ which can result in [[potassium|hypokalemia]] watch for dehydration, if it does it's job too well pharmacokinetics oral, IV, technically IM but that doesn't happen action time PO - 60 minutes IV - 5 minutes they're going to need the toilet fall risk, be careful **Furosemide** (brand name: **Lasix**) is a diuretic used to treat [[hypertension]], [[edema]] in [[heart failure]], [[cirrhosis]] of the liver, [[kidneys|renal disease]]. It's hard on the kidneys because it puts them into overdrive. **Routes** Furosemide can be taken PO, IM and IV **Contraindications** - hold for systolic < 100 - Because the total [[body fluids]] goes down, this can lower you blood pressure - hold for [[potassium|K+]] < 3.5 - Salts follow water. When the extra urine leaves the body [[potassium]] levels can drop. ## Potassium Sparing Diuretics K+ sparing (spironolactone) [[renin-angiotensin-aldosterone system|aldosterone]] antagonist can take up to 48 hours to work corrects the problem that loop diuretics have there is a risk of retaining too much K+ **Spironolactone** (brand name: **Aldactone**) is a potassium sparing diuretic ## Osmotic Diuretics osmotic (mannitol) can be used to decrease [[intercranial pressure]] as well as interocular pressure creates an osmotic force which prevents the reabsorption of water can leave the capillary beds in the periphery (not the brain) this can lead to periphery edema pulmonary edema too! be very careful for heart failure patients! probably won't be proscribed anyway used most often in ICU with brain edema, because it draws water off the brain action IV - 60 minutes, can last up to 8 hours ## Thiazides thiazide (hydrochlorothiazide, or HCTZ) depend on healthy kidneys, won't be given for patients with kidney malfunction action - about 2 hours, lasts 12 increases sensitivity to the sun! (i.e. it's easier to get sunburnt) These work differently and can raise calcium levels, so watch out for [[hypercalcemia]]. ___