Unit 2- study guides Flashcards
(36 cards)
most likely electrolyte imbalances associated with use of furosemide (Lasix)
•hyponatremia •hypochloremia •hypokalemia *due to excessive secretion *often leads to dehydration
why can hyperglycemia occur with use of furosemide (Lasic)
•due to inhibition of insulin release
•uncommon complication of furosemide use
*SMBG crucial in diabetics
What is your primary concern for a patient taking digoxin and HCTZ
•thiazides promote K+/Na+ loss, so there is a potential for increased dig toxicity
What are the signs/symptoms of electrolyte imbalance in clients taking HCTZ
•dehydration s/s: thirst, oliguria, wt loss, etc
•thrombotic/embolism s/s: headache, calf pain
•ototoxicity
•dysrhythmias
•hypotension s/s
*can be avoided w/ alternate-day dosing
difference b/t furosemide and thiazide diuretics
•thiazide used for HTN, edema, and diabetes insipidus
•loop used for CHF or severe edema
•loop severe fluid loss, even when urine flow is scant
•thiazide cease to fxn when urine flow scant
•loop work faster
•thiazide can be combined w/ ototoxic drugs w/o risk of hearing loss (loop cannot)
*both have adverse effects on K+ sparing
How does spironolactone achieve its diuretic effect
- competitively inhibit the action of aldosterone on the principal cells and therefore decrease the expression of the exchanger
- less Na reabsorption leads to diuresis
spironolactone (aldactone) AEs
•hyperkalemia (no Na/K exchange) •endocrine effects (b/c steroid derivative) -gynecomastia -menstrual irregularity -deep voice -impotence (helpless) -hirsutism (abnormal hair growth)
drugs that are contraindicated for patients taking spironolactone (Aldactone)
- K+ supplements
- other K+ sparing agents
- ACEIs
- ARBs
- DRIs
drugs that are commonly combined in patients taking spironolactone (Aldactone)
- thiazide and loop diuretics
* spironolactone counteracts K+ wasting effects of the more powerful diuretic
Why is mannitol (Osmetrol) used in the treatment of increased intracranial/intraocular (glaucoma) pressure
•raises serum osmolality and drawing fluid back into vascular/extravascular space
Mannirol is contraindicated in what patient?
•pt w/ heart dz b/c may precipitate CHF and pulmonary edema
What would you tell a client who has a new prescription for Lasix or HCTZ? What information do THEY need
- monitor/keep log of BP and weight
- report signs of hypokalemia or hypovolemia (dizzy, wt loss, GI distress, weakness, etc)
- consume foods high in K+
- SMBG in diabetics
- observe for hypomagnesmia (weak, twitch, tremor)
- adequate fld intake
What is the most common complaint from patients taking ACE inhibitors?
•cough
•angioedema
-edema of tongue, glottis, and pharynx
Why are patients at risk for hyperkalemia while taking an ACE inhibitor
- secondary to inhibition of angiotensin II production is aldosterone release
- hypoaldosterone state causes K+ retention by kidney b/c nothing to act on Na/K exchanger
What is the difference between ACE inhibitors and Angiotensin II receptor blockers?
- ACE inhibitors prevent the formation of angiotensin II from angiotensin I
- ARBs antagonize angiotensin II at activation sites
How does the drug verapamil decrease blood pressure?
•blocks Ca channels in heart AND blood vessels
- causes peripheral dilation (reduces arteriole pressure)
- increases coronary perfusion
- reduces HR at SA node
- reduces AV node conduction
- decreases FOC
the most common side effect of verapamil
•constipation
•minimized by increasing dietary fluids and fiber
*result of Ca channel blockade in smooth muscle of intestine
What is a common side effect of most anti-hypertensive medications?
- hypotension
- sedation
- sexual dysfunction
What pharmacological effects does digoxin have on the heart
- increase contractile force of heart, which increases cardiac output (positive ionotropic)
- also alters electrical activity of heart, decreasing rate (negative chronotropic)
digoxin and Na,K-ATPase
•inhibits
•results in K+ being lost from heart cells
•results in an increase in Na+ in heart cells
•increased intracellular Na+ is then exchanged for extracellular Ca2+, which enhances myocardial ctx
*more force generated w/o increased O2 consumption
digoxin and slowing HR
•slows rate of SA depolarization
•stimulates vagus nerve
*allows more filling of heart and improves cardiac output
What laboratory value must be checked during digoxin therapy
- potassium
* pt at risk for hypokalemia, which leads to dysrhythmias
Describe at least three clinical manifestations of digoxin toxicity
- fatigue
- weakness
- vision changes
- GI effect
What drugs are contraindicated during digoxin therapy
- thiazide/loop diuretics -> hypokalemia
- ACEI/ARBs -> dec. dig effects
- sympathomimentics -> inc. contractile force
- quinidine-> toxicity
- verapamil -> dec. dig effects; toxicity
