The most common side effects of Protonix, according to WebMD, include diarrhea, vomiting, stomach cramps and gas. Also prevalent are headaches, dizziness and joint pain. Rash and general malaise are less frequently experienced.
Protonix is a proton-pump inhibitor designed to block acid production in the stomach, notes Everyday Health. It can be used to treat gastroesophageal reflux disease, erosive esophagitis and conditions in which the stomach over-produces acid.
Taking Protonix for extended periods may affect the body's absorption of vitamin B-12, which could result in a deficiency. Magnesium levels may also be at risk, potentially causing muscle spasms, irregular heartbeat and seizures, states Everyday Health. Low magnesium levels can be corrected by taking a supplement or discontinuing treatment.
Rare but severe side effects of Protonix include life-threatening allergic reaction, acute liver failure, atrophic gastritis, and toxic epidermal necrolysis, explains WebMD. A decrease in certain blood cells may lead to deficiencies, and serious muscle damage can cause kidney failure. Acute sinus infections, nausea, dry mouth, confusion and drowsiness are other rare side effects. Some patients have reported hallucinations, itching, loss of taste and low energy.
Everyday Health recommends seeking immediate medical help if symptoms like difficulty breathing or swallowing, fever, muscle spasms, or seizures occur. Blistering or peeling skin, uncontrollable shaking, severe diarrhea, swelling around the face, and irregular, fast or pounding heartbeat also warrant immediate medical attention.