Allergy to potassium? every time i get potassium (tablet 330mg) i feel bad. it is possible i have allergy?

Potassium : Potassium tablets are large and a common side effect can be nausea or stomach upset. This is considered a "sensitivity" and does not necessarily indicate an allergy. Try taking the medication with food, to help with the stomach upset. Allergic reactions entail an inflammatory response where the body is looking to fight a foreign body. Allergic reactions include: rash, hives, shortness of breath, tightness to the airway, swelling and redness to the skin. If you experience any signs of an allergic reaction as mention above and if they seem to be associated with taking the potassium pill, stop taking it and call your doctor immediately to get a different source of potassium. It is not okay to not take potassium supplements if your doctor has prescribed them so follow up immediately.

Unlikely: Potassium tablets can make people have some GI upset or general feeling of unwell, but it is usually due to the pill itself and/or the formulation. Consider asking your doctor to switch to a different formulation or brand.