(General Key Points)
This is part one – we’ll be reviewing Diuretics. Next week we’ll post about minerals and renal.
Enjoy your weekend.
Diuretics increase fluid loss via urine output
Major uses of diuretics include prevention of renal failure and management of hypertension.
Most diuretics work by blocking reabsorption of Na+ and Cl–; the more ion absorption blocked, the more fluid that is lost.
Potassium is necessary for nerve impulse conduction and regulation of acid-base balance.
Calcium is critical to normal metabolic processes of the heart, nerves, muscles, bones, and coagulation.
Mineral supplements tend to cause GI distress and should be administered with a full glass of water or with meals.
High Ceiling Loop Diuretics
In upper Loop of Henle to block reabsorption of Na+/Cl–/H2O leads to Extensive diuresis.
Example: furosemide (Lasix) — Others: ethacrynic acid (Edcrin), bumetanide (Bumex), Torsemide (Demadex)
Therapeutic Uses: Pulmonary edema d/t heart failure, Works well with renal impairment, Hypercalcemia r/t stone formation, Reserved for conditions unresponsive to other diuretics (e.g. edema d/t liver, cardiac or renal disease; hypertension)
Dehydration (notify physician output < 30 mL/hr)
Ototoxic – furosemide (temp); ethacrynic acid (permanent) – no other ototoxics
Hyperglycemia, hyperuricemia, decreases [Ca2+], [Mg2+]
Contraindications/Precautions: Pregnancy (C), Caution ĉ diabetes, gout
Interactions: Digoxin toxicity r/t decreased K+, NSAIDs blunt diuretic effect, Antihypertensives – Additive hypotensive effect, [Li] increases d/t diuresis
- Daily weights, infuse slowly (20 mg/min), increase K+ foods (avocado, strawberry, banana, potato, spinach, tomato, meat, carrots), decreased Mg2+ signs: muscle twitch and tremor
In early DCT to block Na+/Cl–/H2O reabsorption – promote diuresis when renal function is not impaired.
Example: hydrochlorothiazide (HydroDIURIL) — Others: chlorothiazide (Diuril), indapamide
1st choice essential hypertension, Edema of mild-to-moderate heart failure and liver/kidney disease.
Contraindications/Precautions: Pregnancy (B), NO breastfeeding, Caution ĉ renal impairment – may not be effective
Digoxin toxicity d/t decreasedK+, Antihypertensives: Additive effect, increased lithium levels, NSAIDs blunt diuretic effect
Alternate day dosing can decrease electrolyte imbalances
Increased K+ foods (avocado, strawberry, banana, potato, spinach, tomato, meat)
Block aldosterone action resulting in K+ retention and Na+/H2O excretion.
Example: spironolactone (Aldactone) — Others: triamterene (Dyrenium), amiloride (Midamore)
Therapeutic Uses: Combined with other diuretics for K+-sparing effect, Blocks aldosterone in hyperaldosteronism, Heart failure
Hyperkalemia (insulin injection drives K+ back into cell)
Endocrine effects: Irregular menses or impotence
ACE inhibitors (lisinopril) leads to increased hyperkalemia
K+ supplements leads to increased hyperkalemia
Triamterene may color urine blue
Increases blood osmolality thus attracting fluid (e.g. 3rd spacing, CSF, intraocular)
Examples: mannitol (Osmitrol) — Others: urea, glycerin, isosorbide
Decreases ICP, Decreases intraocular pressure (IOP), Prevent renal failure in hypovolemic shock or severe hypotension., Promote Na+ retention and H2O excretion in hyponatremia and fluid V excess
Heart failure / pulmonary edema
Renal failure (urine < 30 mL/hr, creatinine > 1.2 mg/dL, BUN > 20 mg/dL
Fluid and electrolyte imbalance
Lasix complements through renal excretion of fluid drawn by osmotics.
Most effective given as a bolus, Use filter to prevent crystals, Monitor serum osmolarity and every 6 hours / urine osmolarity daily
Past Medication posts –
Respiratory Meds – http://www.nclexreviewonline.com/respiratory-system-nclex-medications/
Nervous System Meds (4 parts)
Part 1 – http://www.nclexreviewonline.com/cardiac-drugs-for-nclex-part-1/
Part 2 – http://www.nclexreviewonline.com/nclex-cardiac-drugs-part-2/
Part 3- http://www.nclexreviewonline.com/nclex-cardiac-drugs-part-3/
Pain Meds and Inflammation – http://www.nclexreviewonline.com/nclex-test-help-pain-meds-and-inflammation/
Immunity and Chemo – http://www.nclexreviewonline.com/nclex-drugs-immunity-and-chemotherapy/
Anti Infective Drugs – http://www.nclexreviewonline.com/anti-infective-drugs-part-1/
More information can be found on our blog – http://www.nclexreviewonline.com/the-blog/