SIDE EFFECTS: Stomach pain/upset, nausea, vomiting, or diarrhea may occur. See How to Use for ways to reduce stomach upset. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

For some capsule forms of this medication, an empty capsule shell may appear in your stool. This is harmless.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: difficult/painful swallowing, feeling as if the capsule/tablet is stuck in your throat.

Tell your doctor immediately if any of these rare but very serious side effects occur: vomit that looks like coffee grounds, stomach/abdominal pain or swelling, black/tarry stools.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the K-Tab (potassium chloride extended-release tablets) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before taking potassium, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: high potassium blood levels, severe kidney disease (e.g., chronic kidney failure, inability to make urine), adrenal gland problems, severe conditions of tissue breakdown (e.g., severe burns, traumatic injury).

Due to rare reports of stomach/intestinal ulcers and bleeding with sustained-release potassium chloride products, the capsules/tablets should be used only in patients who cannot take liquid or effervescent potassium forms. Patients with blockage/narrowing/slowed movement of the esophagus/stomach/intestines (e.g., diabetic gastroparesis, esophageal compression due to an enlarged heart) are at greater risk for these side effects and should use liquid or effervescent potassium forms.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems, certain types of heart disease (e.g., atrioventricular block), stomach ulcers.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be more sensitive to the effects of this drug.

This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

Potassium passes into breast milk. Consult your doctor before breast-feeding.