Details About Overdose or Poisoning Generic Salt :: Potassium
Potassium
Drug Pharmacology ::
I. Pharmacology. Potassiumis the primary intracellular cation, which is essential for maintenanceof acid-base balance, intracellular tonicity, transmission of nerveimpulses, contraction of cardiac, skeletal, and smooth muscle, andmaintenance of normal renal function (and ability to alkalinize urine).Potassium also acts as an activator in many enzyme reactions andparticipates in many physiological processes such as carbohydratemetabolism, protein synthesis, and gastric secretion. Potassium iscritical in regulating nerve conduction and muscle contraction,especially in the heart. A variety of toxins cause alterations in serumpotassium levels (see Table I–27, Hyperkalemia and hypokalemia).
Drug Indications ::
Indications
For treatment or prevention of hypokalemia (see Hyperkalemia and hypokalemia).
Supplement to bicarbonate therapy (see Bicarbonate, Sodium) for alkalinization of urine.
Drug Contra-Indications ::
III. Contraindications./b>
Potassiumshould be administered cautiously in patients with renal impairment orimpairment of renal excretion of potassium (ACE inhibitor toxicity andhypoaldosteronism, potassium-sparing diuretics) to avoid the potentialfor serious hyperkalemia.
Potassiumshould be administered cautiously in patients with impairment ofintracellular transport of potassium (due to inhibition of Na-K ATPasepump with cardiac glycosides or inhibition of beta-adrenergic transportwith beta blockers). Administration of potassium may lead to largeincremental rises in serum levels.
Potassium should be administered cautiously in patients with intracellular spillage of potassium (rhabdomyolysis, hemolysis).
Potassium should be administered cautiously in patients with severe acute dehydration.
Drug Adverse Effects ::
IV. Adverse effects
Nausea, vomiting, abdominal pain, and diarrhea with oral administration.
Parenteral administration. Note:DO NOT use undiluted injectable potassium preparations: directinjection can be lethal if given too rapidly; pain at the injectionsite and phlebitis may occur, especially during infusion of solutionscontaining greater than 30 mEq/L.
Hyperkalemia is the most serious adverse reaction (see Hyperkalemia and hypokalemia).
Use in pregnancy. FDA category C (indeterminate) (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions
Drug interactions, see Contraindications, above.
NumerousIV incompatibilities: mannitol, diazepam, dobutamine, ergotamine, fatemulsion, nitroprusside, ondansetron, phenytoin, penicillin G sodium,promethazine, streptomycin.
Serum potassium levels may be fictitiously elevated if the blood sample is hemolyzed.
Drug Dose Management ::
Dosage and method of administration (adults and children)
The dose is variable and depends on the serum potassium level andseverity of symptoms. The normal serum potassium level is 3.5–5 mEq/L.For parenteral administration, potassium must be diluted (see AdverseEffects, above).
The usual daily adult maintenance dose is 40–80 mEq. The usual daily pediatric maintenance dose is 2–3 mEq/kg or 40 mEq/m2.
Potassiumdepletion resulting in a 1-mEq/L decrease in serum potassium mayrequire 100–200 mEq for replacement to restore body stores. Thisreplacement requirement will be offset with changes or corrections inintracellular transport (reversal of methylxanthine or beta-adrenergicagonist toxicity).
Fora serum potassium of 2.5 mEq/L or greater, the maximum infusion rate ofpotassium in adults is 10 mEq/h, maximum concentration is 40 mEq/L, andmaximum dose is 200 mEq per 24 hours. Do not exceed 1 mEq/kg/hr or 30mEq per dose for IV use in pediatric patients. Adjust volume of fluidto body size of patient
E.For a serum potassium of less than 2.0 mEq/L, the maximum infusion rateof potassium in adults is 40 mEq/h, although infusions of 50 mEq/h havebeen used for short periods of time with constant EKG monitoring andfrequent determination of laboratory values. The maximum concentrationis 80 mEq/L, and maximum dose is 400 mEq per 24 hours.
F. Continuous cardiac monitoring with frequent laboratory monitoring is essential during administration of IV potassium.
Drug Chemical Formulations ::
Formulations
Potassium acetate injection: 2 mEq/mL in 20-, 50-, and 100-mL vials; 4 mEq/mL in 50-mL vials.
Potassiumchloride for injection concentrate: 2 mEq/mL in 250 and 500 mL; 10 mEqin 5-, 10-, 50-, and 100-mL vials and 5-mL additive syringes; 20 mEq in10- and 20-mL vials, 10-mL additive syringes, and 10-mL ampules; 30 mEqin 15-, 20-, 30-, and 100-mL vials and 20-mL additive syringes; 40 mEqin 20-, 30-, 50-, and 100-mL vials, 20-mL ampules, and 20-mL additivesyringes; 60 mEq in 30-mL vials; and 90 mEq in 30-mL vials.
The suggested minimum stocking level to treat a 70-kg adult for the first 24 hours is 500 mEq.
