Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
HEMICLOR vs MICRO-K
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Hemichlor (HEMICLOR) is a brand name for a combination product containing chlorpheniramine and pseudoephedrine. Chlorpheniramine is a first-generation antihistamine that antagonizes histamine at H1 receptor sites, reducing allergic symptoms. Pseudoephedrine is a sympathomimetic amine that directly stimulates alpha-adrenergic receptors, causing vasoconstriction and decongestion.
Potassium is the principal intracellular cation, essential for maintaining cellular tonicity, electrical neutrality, and enzymatic reactions. It modulates neuromuscular transmission, cardiac contractility, and acid-base balance.
Relief of symptoms associated with seasonal and perennial allergic rhinitis, including nasal congestion, sneezing, rhinorrhea, and pruritus,Off-label: Adjunctive treatment for acute sinusitis and common cold symptoms
Treatment of hypokalemia,Prevention of hypokalemia in patients at risk (e.g., on diuretics, digitalis)
50-100 mg intravenously every 6 hours or 100 mg orally every 12 hours.
Oral: 20-40 m Eq (1-2 capsules) two to four times daily; maximum 100 m Eq/day. Each capsule contains 8 m Eq (600 mg) of potassium chloride in a wax matrix extended-release formulation.
Terminal elimination half-life 18–24 hours in normal renal function; prolonged to 36–48 hours in moderate renal impairment (Cr Cl 30–50 m L/min); adjust dosing interval in renal disease.
Not applicable; potassium is an electrolyte with no true elimination half-life; whole-body turnover half-life is approximately 12-24 hours, clinically relevant for dosing intervals.
Chlorpheniramine is extensively metabolized in the liver via CYP450 enzymes, primarily CYP2D6, and excreted renally as metabolites. Pseudoephedrine is partially metabolized in the liver by N-demethylation and excreted largely unchanged in urine; its metabolism is not significantly enzyme-dependent.
Potassium ions are not metabolized; they are primarily excreted unchanged by the kidneys (90%), with minor losses via feces and sweat.
Primarily renal (85–90% as unchanged drug via glomerular filtration and tubular secretion); biliary/fecal < 5%.
Renal: approximately 90% of absorbed potassium is excreted in urine; biliary/fecal: less than 10% eliminated via feces.
70–80% (primarily to albumin).
None; potassium is not significantly bound to plasma proteins.
0.3–0.5 L/kg (indicates moderate tissue distribution).
0.5-0.7 L/kg; total body water distribution; clinically indicates extensive intracellular uptake (98% intracellular).
Oral: 40–60% (due to first-pass metabolism; food may reduce absorption).
Oral: approximately 80-90% for Micro-K (extended-release); absorption occurs in small intestine.
GFR 30-50 m L/min: 50 mg IV every 12h or 50 mg PO every 24h; GFR 10-29 m L/min: 50 mg IV every 24h or 25 mg PO every 24h; GFR <10 m L/min: 25 mg IV every 48h or avoid use.
e GFR ≥60 m L/min: No adjustment. e GFR 30-59: Reduce dose by 25-50% and monitor potassium. e GFR 15-29: Reduce dose by 50-75% and monitor potassium. e GFR <15: Avoid use or use with extreme caution; maximum 20 m Eq/day with frequent monitoring.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use.
No specific dosing adjustments recommended for hepatic impairment. Monitor potassium levels as hepatic disease may affect potassium homeostasis.
5-10 mg/kg IV every 6h, max 100 mg/dose.
Oral: <1 year: 1-2 m Eq/kg/day divided 2-4 times. 1-18 years: 1-3 m Eq/kg/day divided 2-4 times; maximum 100 m Eq/day. Extended-release capsules not recommended for children unable to swallow whole capsules.
Start at lower end of dosing range (50 mg IV every 12h or 50 mg PO every 24h) due to reduced renal function and increased sensitivity.
Start at low end of dosing range (20-40 m Eq/day) due to decreased renal function; maximum 100 m Eq/day. Monitor renal function and potassium levels closely.
No FDA black box warning is present for HEMICLOR.
None
Cardiovascular effects: Use with caution in patients with hypertension, ischemic heart disease, or arrhythmias,CNS depression: Chlorpheniramine may cause sedation; avoid concurrent use with alcohol or other CNS depressants,Monoamine oxidase inhibitor (MAOI) interaction: Concomitant use with MAOIs or within 14 days of discontinuation can precipitate hypertensive crisis,Urinary retention: Use cautiously in patients with prostatic hypertrophy or bladder neck obstruction,Photosensitivity: Chlorpheniramine may increase risk of photosensitivity reactions
Hyperkalemia risk, especially in patients with renal impairment, diabetes, or those receiving potassium-sparing diuretics, ACE inhibitors, or ARBs,Suspect gastrointestinal obstruction or perforation with slow-release formulations; caution in patients with severe GI disorders,Use with caution in patients with cardiac disease, particularly those on digoxin,Monitor serum potassium levels regularly
Hypersensitivity to chlorpheniramine, pseudoephedrine, or any component,Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of MAOI therapy,Severe hypertension or severe coronary artery disease,Narrow-angle glaucoma,Urinary retention,Breastfeeding (relative contraindication due to pseudoephedrine excretion)
Hyperkalemia (serum potassium >5.5 m Eq/L),Renal failure or severe renal impairment (e.g., oliguria, anuria),Addison's disease,Acute dehydration,Concomitant use with potassium-sparing diuretics (e.g., amiloride, spironolactone, triamterene),Concomitant use with eplerenone,Solid dosage forms in patients with delayed gastric emptying or esophageal compression
Avoid alcohol and grapefruit juice. Take with food to reduce gastrointestinal upset. Limit caffeine intake as it may worsen anxiety or gastrointestinal symptoms.
Avoid high-potassium foods (e.g., bananas, oranges, spinach, potatoes, tomatoes) and potassium-based salt substitutes. Consuming large amounts of these may increase risk of hyperkalemia.
Hemichlor (hydrochlorothiazide) is contraindicated in pregnancy due to risk of fetal/neonatal jaundice, thrombocytopenia, and electrolyte disturbances. First trimester: associated with neural tube defects in animal studies and possible oligohydramnios. Second/third trimester: risk of fetal bradycardia, hyponatremia, hypokalemia, and decreased placental perfusion.
Potassium chloride (Micro-K) is not associated with major congenital malformations. Normal maternal serum potassium levels are required for fetal development. Hypokalemia or hyperkalemia may increase risks. No trimester-specific risks documented.
Hydrochlorothiazide is excreted in breast milk in low concentrations. M/P ratio approximately 0.04-0.06. No adverse effects reported in infants, but may suppress lactation at high doses. Use with caution, monitor infant for electrolyte disturbances.
Potassium is a normal constituent of breast milk. Supplemental potassium does not affect milk potassium content. M/P ratio not applicable. Use with caution if maternal renal function impaired.
Pregnancy increases volume of distribution and renal clearance of hydrochlorothiazide, potentially reducing peak serum concentration. However, due to fetal risks, thiazide diuretics are generally avoided in pregnancy. If essential, use lowest effective dose and monitor maternal/fetal status closely. No specific dose adjustment studies exist.
No standard dose reduction required. Pharmacokinetic changes in pregnancy (increased GFR, blood volume) may increase potassium requirements or decrease serum levels; monitor and adjust dose to maintain normal serum potassium (3.5-5.0 m Eq/L).
HEMICLOR contains clidinium bromide (quaternary ammonium anticholinergic) and chlordiazepoxide (benzodiazepine). Monitor for anticholinergic side effects (dry mouth, blurred vision, urinary retention, constipation). Avoid use in patients with narrow-angle glaucoma, obstructive uropathy, or myasthenia gravis. Chlordiazepoxide may cause dependence; limit duration to 4-8 weeks. Use with caution in elderly due to increased sensitivity to anticholinergic effects and risk of falls.
Micro-K (potassium chloride extended-release) is used to prevent and treat hypokalemia. Avoid use in severe renal impairment, metabolic acidosis, or conditions with high potassium levels. Slow-release formulations reduce GI irritation but may be contraindicated in patients with GI motility disorders. Do not crush or chew capsules; administer with food and a full glass of water. Monitor serum potassium and renal function regularly.
Take exactly as prescribed; do not increase dose or stop abruptly.,May cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you.,Avoid alcohol and other CNS depressants.,Report any signs of urinary retention, severe constipation, or blurred vision.,Do not share with others; risk of dependence.,Store at room temperature away from moisture and heat.
Take this medication with food and a full glass of water to reduce stomach upset.,Swallow the capsule whole; do not crush, chew, or open it.,Do not suddenly stop taking this medication without consulting your doctor.,Avoid salt substitutes or potassium-containing supplements unless approved by your doctor.,Seek immediate medical attention if you experience signs of high potassium levels: muscle weakness, irregular heartbeat, or tingling in hands/feet.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about HEMICLOR vs MICRO-K, answered by our medical review team.
HEMICLOR is a Electrolyte Supplement that works by Hemichlor (HEMICLOR) is a brand name for a combination product containing chlorpheniramine and pseudoephedrine. Chlorpheniramine is a first-generation antihistamine that antagonizes histamine at H1 receptor sites, reducing allergic symptoms. Pseudoephedrine is a sympathomimetic amine that directly stimulates alpha-adrenergic receptors, causing vasoconstriction and decongestion.. MICRO-K is a Electrolyte Supplement (Potassium) that works by Potassium is the principal intracellular cation, essential for maintaining cellular tonicity, electrical neutrality, and enzymatic reactions. It modulates neuromuscular transmission, cardiac contractility, and acid-base balance.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between HEMICLOR and MICRO-K depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of HEMICLOR is: 50-100 mg intravenously every 6 hours or 100 mg orally every 12 hours.. The standard adult dose of MICRO-K is: Oral: 20-40 m Eq (1-2 capsules) two to four times daily; maximum 100 m Eq/day. Each capsule contains 8 m Eq (600 mg) of potassium chloride in a wax matrix extended-release formulation.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between HEMICLOR and MICRO-K in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. HEMICLOR is classified as Category C. Hemichlor (hydrochlorothiazide) is contraindicated in pregnancy due to risk of fetal/neonatal jaundice, thrombocytopenia, and electrolyte disturbances. First trimester: associated . MICRO-K is classified as Category C. Potassium chloride (Micro-K) is not associated with major congenital malformations. Normal maternal serum potassium levels are required for fetal development. Hypokalemia or hyperk. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.