What are the side effects of KCl in NS?

As with all injections, administering KCl in NS may cause swelling or irritation at the site of the injection. Talk to a doctor immediately if the injection site develops an infection or if the person receiving KCl in NS develops a fever. Allergic reactions to KCl in NS are possible. Seek emergency care if the person receiving KCl in NS experiences difficulty breathing, hives, itchy rash or swelling in the face, mouth or throat. Common side effects of potassium-containing solutions like KCl NS include: nausea, abdominal pain, vomiting and diarrhea. If too much KCl in NS is administered, the result can be symptoms of an overdose of potassium, like muscle weakness, confusion or irregular or slow heart rate. Too much KCl in NS can also cause dangerously high blood volume, which could cause cardiac problems or fluid buildup in the lungs. Overdoses should be promptly treated by a medical professional.