What is Klor-Con M20: Uses, Warnings & Interactions

Updated Jul 29, 2025  •  Published Dec 30, 2020

Klor-Con M is a prescription supplement that treats or prevents hypokalemia (low potassium). The tablet employs a technology called “microencapsulation” to first provide immediate-release potassium chloride and then gradually release extended-release potassium chloride. Dosage strengths are measured in milliequivalents of potassium, so Klor-Con M20 has 20 milliequivalents of potassium, the highest dosage strength available. Lower dosage strengths are available as Klor-Con M10 and Klor-Con M15.

Klor-Con M20 overview

BRAND NAMES:

  • Klor-Con M20

Generic Names:

  • Extended-release potassium chloride microencapsulated

Uses:

  • Prevents and treats low potassium levels in the blood

Therapeutic Classes:

  • Electrolyte supplement, potassium supplement

Forms:

  • Extended-release tablet

How it’s taken:

  • By mouth

What is Klor-Con M20 used for?

Klor-Con M20 treats or prevents hypokalemia (low levels of blood potassium).

What form(s) does Klor-Con M20 come in

  • Extended-release tablets

    • 1,500 mg potassium chloride (20 mEq potassium)

What are common Klor-Con M20 doses?

  • For the treatment of low potassium:

    • In adults: 40–100 mEq (two to five tablets) daily taken in divided doses

  • For the prevention of low potassium:

    • In adults: 20 mEq (one tablet) daily

Common Klor-Con M20 prescriptions

  • Klor-Con M20
    120 tablets extended release bottle

  • Klor-Con M20
    180 tablets extended release bottle

  • Klor-Con M20
    30 tablets extended release bottle

  • Klor-Con M20
    90 tablets extended release bottle

  • Klor-Con M20
    20meq tablet extended release

How to take Klor-Con M20

  • Follow all the prescriber’s instructions. Do not use more than directed.

  • Take one or more doses daily.

    • For low daily doses (≤20 mEq), the prescriber may ask you to take one dose daily. 

    • For higher doses (>20 mEq), the prescriber will probably ask you to take two or more smaller doses during the day (usually one tablet per dose).

  • Follow the healthcare provider’s instructions about any special diet or supplements.

  • Take Klor-Con tablets with food or right after eating to avoid gastrointestinal problems.

  • Swallow the tablet whole with a full glass of water or other liquid.

  • For people who cannot swallow a tablet:

    • Break the tablet in half and take each half with water. OR

    • Place the tablet in half a glass of water and let it disintegrate. It takes about two minutes. When the tablet has disintegrated, stir the water for 30 seconds with a spoon. Briefly swirl the mixture and drink all of it. Add a little bit more water and drink that. Add a little bit of water again and drink that.

  • Store Klor-Con M20 at room temperature in a tightly closed container.

What to do if you miss a dose of Klor-Con M20

  • Take a dose as soon as possible. 

  • If it is almost time for your next dose, then take the next dose at its regular time and skip the missed dose. 

  • Do not take extra medicine to make up for a missed dose.

Klor-Con M20 contraindications

  • This medicine is not safe for all people. 

  • Do not take potassium chloride ER if you have:

    • High potassium levels

    • Slow stomach emptying (gastroparesis)

    • Compression of the esophagus

    • Esophageal ulcers

  • Do not take Klor-Con if you’re also taking opioids or anticholinergic drugs.

Klor-Con M20 warnings

  • The prescribing healthcare provider will do blood tests at regular visits to check potassium levels. Keep all appointments.

  • Tell other healthcare professionals treating you about taking Klor-Con.

  • Tell the prescriber if you are pregnant, breastfeeding, or have:

    • Kidney problems

    • Swallowing problems

    • Liver cirrhosis

    • Digestive system problems

    • Gastrointestinal bleeding

    • Metabolic acidosis

  • Extended-release potassium chloride can cause serious problems, including:

    • High potassium (hyperkalemia)

    • Digestive system bleeding, ulcers, or perforation

  • Klor-Con M20 can cause high potassium in people who are dehydrated. Drink plenty of fluids when taking this drug.

Klor-Con M20 interactions

  • Because of the risk of high potassium, potassium chloride ER should not be taken with:

    • Potassium-sparing diuretics (triamterene and amiloride are contraindicated for use with potassium chloride ER capsules)

    • Potassium supplements

    • Potassium salt substitutes

  • To avoid drug interactions, tell the prescriber about all the drugs and supplements being taken, particularly:

  • Tell other prescribers about Klor-Con treatment before they prescribe new medications.

Klor-Con M20 side effects

Serious side effects

Talk to a healthcare provider if you notice any signs or symptoms of a possible serious side effect, including:

  • Severe stomach pain, vomiting, vomiting up blood, vomiting blood clots

  • Black and tarry stools, blood in the stools

  • Pain in the throat, chest pain (esophageal pain)

  • Confusion, irregular heartbeats, difficulty breathing, weakness, numbness in your hands, feet, or lips

  • Fast, slow, or uneven heartbeats

  • Allergic reaction: Itching, hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Less serious side effects

  • Mild nausea

  • Vomiting

  • Flatulence

  • Abdominal pain or discomfort

  • Diarrhea

Sources:

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