* Hypokalemia (low potassium levels). This is the most common side effect of potassium chloride, and it can occur when the medication is taken in high doses or for a long period of time. Symptoms of hypokalemia can include muscle weakness, fatigue, nausea, vomiting, and diarrhea.

* Hyperkalemia (high potassium levels). This can occur when the medication is taken in too high of a dose or if the patient has kidney problems. Symptoms of hyperkalemia can include muscle weakness, tingling or numbness in the hands or feet, nausea, vomiting, and diarrhea.

* Gastrointestinal side effects. These can include nausea, vomiting, abdominal pain, and diarrhea.

* Skin rash. This can occur in some people who are allergic to potassium chloride.

* Cardiovascular side effects. These can include hypotension (low blood pressure) and arrhythmias (irregular heartbeats).

It is important to talk to your doctor about the risks and benefits of potassium chloride before taking it.