Drugs for Hypo/Hyperkalemia Flashcards
At what plasma level of K is hyperkalemia
> 5.2 mEq/L
At what plasma level of K is hypokalemia
< 3.7 mEq/L`
in acidemia does K move in or out of the cell?
K+ moves out to exchange with H+
in alkalemia does K move in or out of the cell
K+ moved in to exchanged with H+
Which factors move Potassium out of the cell
a-Agonist Insulin deficiency Aldosterone B2-Blockers Acidosis Hyperosmolarity Exercise Cell Lysis
What factors move potassium into the cell
Insulin*** B2-Agonist Aldosterone deficiency a-blockers Alkalosis Hypoosmolarity
What is the overall effect of high sodium diet on K homeostasis
No net change
increase Na decreases aldosterone -> no K secretion
increase Na increases GFR -> increase K secretion
balances out
What is the effect of hypokalemia on tissue membrane polarization
hyperpolarization
What is the effect of hyperkalemia on tissue membrane polarization
depolarization
What is the MOA of furosemide
Blocks Na-K-Cl cotransporter in loop of henle
What are the adverse effects of furosemide
hypokalemia, hyponatremia, hypocalcemia, hyperglycemia, hyperuricemia, ototoxic, sulfonamide allergy
If you wanted a loop diuretic with a longer half life and better oral absorption what drugs would you pick
torsemide
bumetanide
if you wanted a loop diuretic to bypass the sulfa allergy, what drug would you pick
ethacrynic acid
What is the MOA of HCTZ
blocks Na-Cl cotransporter
If you wanted a thiazide diuretic with a longer half-life than HCTZ what drug would you pick
Chlorthalidone
metolazone
What is the MOA of Amiloride
Blocks ENAc in the collecting ducts, counteracts K loss
What are the toxicities of Amiloride
Hyperkalemia, hyponatremia, hypovolemia
triamterene alternative
What is the MOA of spironolactone
Aldosterone receptor blocker and partial agonist at androgen receptor
What are the toxicities of spironolactone
hyperkalemia, amenorrhea, hirsutism, gynecomastia
eplerenone: is more selective for aldosterone
What is the major concern when using witch craft alternative diuretics such as dandelion leaves, fennel or St john wort
potential drug interactions that will diminish or enhance the actions of other drugs.
If you have a patient with Acidemia, Normal Anion Gap, and Normal serum Creatinine. What does that patient have?
Renal Tubular Acidosis
hypokalemia mneumonic
GRAPHIC IDEA
GI Loss Renal Tubular Acidosis (type I and II) Aldosterone Paralysis Hypothermia Insulin Excess Cushing Syndrome
Insufficient Intake
Diuretics
Elevated B-adrenergic activity
Alkalosis
What are the goals of the treatment of hypokalemia
- Prevent life threatening conditions
- Replace K+ deficit
- Diagnose underlying cause
In the treatment of hypokalemia, what is the amount needed to to replace acute and chronic hypokalemia
acute: 100mEq -> increase .27 mEq/L
Chronic: 200-400 mEq -> 1 mEq/L
What is the hyperkalemia mnemonic
RED FETS
Renal Disease
Excessive Intake
Drugs
Factitious
Endocrine (addisons)
Tissue Release
Shifts out of cell
What are the three categories of treatment of hyperkalemia?
Antagonize cardiac effects - give Ca
Redistribute K into cells -> insulin and glucose, B2-agonist
Facilitate K+ elimination - K losing diuretic
