Potassium Balance/Hypokalemia

Pharmacy Practice 556 with Kopacek/vivian at University of Wisconsin - Madison

About this deck

By: Nicole Picotte
Textbook:

Pharmacotherapy Handbook, Seventh Edition
Created: 2009-03-15
Size: 15 flashcards
Views: 30

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Normal adult Total body K+ level

50-55 mMol/kg - over 95% intracellular

How does aldosterone affect K levels?

Increases excretion of K

What are some things that affect the distribution of K? (ICF vs. ECF)

Na/K pump (towards ICF)

Insulin (towards ICF)

Beta-2 stimulation (towards ICF)

pH (Ion exchange)(variable effect on ICF vs ECF)

Normal serum K levels

3.5-4.8 mMol/L

Causes of hypokalemia

Poor diet (unlikely to be only cause)

Intracellular shift (due to insulin, beta-2 agonist use, endogenous sympathetic tone, alkalemia, xanthines)

GI/sweat loss (vomiting, laxative or enema abuse, overexertion during workout)

Urinary loss

�� -**aldosterone excess,

�� -**steroid use (prednisone)

�� -increased Na excretion

�� -Mg deficiency

�� -metabolic alkalosis

�� -high dose penicillin doses, amphotericin B

Signs/Sx of hypokalemia

Muscle weakness/paralysis

�� -serum K <2.5 mMol/L

Constipation

Cramps, Tetany, paresthesia, weak, tender, ischemic, rhabdomyolysis, (Lower extremity muscles most sensitive)

Cardiac U-waves, digitalis toxicity, arrhythmias in unhealthy hearts

Renal metabolic alkalosis, impaired concentrating ability

Glucose intolerance (decreased insulin secretion)

Sx level and treatment for Serum K

3.0<K<3.5

Usually asymptomatic

Dietary K usually adequate unless on Digitalis

Sx level and treatment for Serum K

2.5<K<3.0

Some muscle weakness, mostly not.�

Tx: Oral supplements

Sx level and treatment for Serum K

2.0<K<2.5

Sx likely

Tx: po suppliments stat, or IV if already in place

Sx and treatment for Serum K

K<2.0

Severe hypokalemia. Muscle weakness, Rhabdomyolysis, etc.

Tx: IV K stat.

Preferred choice of oral potassium supplements

KCl. Most pts with K deficit also have Cl deficit.

Use K-Phosphate, bicarb, citrate, acetate, lactate or gluconate if other deficit present.

What dosage forms can K supplements be found?

Solution (cheap but tastes bad)

Wax matrix tablets

Microencapsulated capsules

SR microcrystalloids

Good food�sources of K�

Lean meat/chicken

Fruits:

banana > OJ > oranges = grapes > pears > apples

Veges:

mushrooms = potatoes = spinach > cauliflower = broccoli > lettuce = tomatoes > carrots

Legumes:

dry chickpeas > canned beans > peas

or use a salt substitute

Drugs used with caution with K supplements

K-sparing diuretics

Trimethoprim

Heparin

Beta-2 blockers

ACEI

A-2 blocker

Why should you use dextrose-free IV fluid when first administering K supplements in an urgent situation?

Dextrose will stimulate insulin release. Want ECF levels to go up and not into ICF too quickly.

About this deck

By: Nicole Picotte
Textbook:

Pharmacotherapy Handbook, Seventh Edition
Created: 2009-03-15
Size: 15 flashcards
Views: 30

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis