MICRO-K 10
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MICRO-K 10 (MICRO-K 10).
Potassium is the major intracellular cation; it is essential for the maintenance of intracellular tonicity, transmission of nerve impulses, contraction of cardiac, skeletal, and smooth muscle, and maintenance of normal renal function. Potassium chloride is absorbed from the gastrointestinal tract and distributes throughout the body. The microencapsulated formulation allows for gradual release of potassium, minimizing gastrointestinal irritation.
| Metabolism | Potassium is not metabolized. Approximately 90% of ingested potassium is excreted in the urine, with the remainder excreted in feces and sweat. There is no hepatic metabolism. |
| Excretion | Primarily renal: 90% of absorbed potassium is excreted in urine as potassium ions; 10% eliminated in feces via biliary and intestinal secretion. |
| Half-life | Not applicable; potassium is not cleared by first-order kinetics. Whole-body potassium turnover half-life is approximately 30 days, but this is not clinically relevant for supplementation. |
| Protein binding | 0% bound to serum proteins; free ion in serum. |
| Volume of Distribution | Total body water: 0.5 L/kg; distributes primarily intracellularly (98% of body potassium is intracellular), but Vd is not a clinically relevant parameter for potassium. |
| Bioavailability | Oral (microencapsulated): 90-100% relative to intravenous; absorption is nearly complete via the gastrointestinal tract. |
| Onset of Action | Oral (microencapsulated): 30-60 minutes as potassium levels rise due to absorption in the small intestine. |
| Duration of Action | Oral: 8-12 hours for a single dose, but potassium homeostasis adjusts via renal regulation; daily dosing maintains steady serum levels. |
10 mEq (2 capsules) orally once daily, or 20 mEq (2 capsules) twice daily, or as directed by physician. Maximum 100 mEq/day.
| Dosage form | CAPSULE, EXTENDED RELEASE |
| Renal impairment | GFR >50 mL/min: no adjustment. GFR 10-50 mL/min: reduce dose by 50% or use with caution. GFR <10 mL/min: contraindicated or use with extreme caution. |
| Liver impairment | No specific Child-Pugh based modifications; use with caution in severe hepatic impairment due to risk of hyperkalemia. |
| Pediatric use | Children: 1-2 mEq/kg/day in divided doses, not to exceed 20 mEq per dose or 100 mEq/day. Minimum dosing weight not specified; safety and efficacy not established in premature infants. |
| Geriatric use | Elderly: start with lower doses (e.g., 10 mEq once daily) due to age-related renal function decline; monitor serum potassium and renal function frequently. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for MICRO-K 10 (MICRO-K 10).
| Breastfeeding | Potassium is a normal constituent of breast milk with an M/P ratio of approximately 0.1-0.2. Supplemental potassium is not expected to cause adverse effects in nursing infants at usual maternal doses. |
| Teratogenic Risk | Potassium chloride is not associated with fetal malformations. In all trimesters, excessive potassium intake can cause maternal hyperkalemia, which may lead to fetal arrhythmias or adverse outcomes. Recommended intakes are safe. |
| Fetal Monitoring |
■ FDA Black Box Warning
None
| Serious Effects |
["Severe renal impairment with oliguria or azotemia","Addison's disease","Acute dehydration","Heat cramps","Hyperkalemia from any cause","Concomitant use of potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride)"]
| Precautions | ["Hyperkalemia risk; use with caution in patients with renal impairment, cardiac disease, or conditions predisposing to hyperkalemia","Gastrointestinal irritation and ulceration; do not crush or chew tablets","May increase serum potassium levels in patients with adrenal insufficiency or diabetes","Use caution with potassium-sparing diuretics or ACE inhibitors"] |
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| Monitor serum potassium levels periodically, especially in patients with renal impairment or on medications affecting potassium. Electrocardiogram monitoring may be indicated in hyperkalemia. No specific fetal monitoring required beyond routine prenatal care. |
| Fertility Effects | No evidence of adverse effects on fertility in animal studies. In humans, potassium chloride is not known to impair fertility or reproductive function. |