Proton pump inhibitors (PPIs) like Nexium and Prilosec have been linked in recent studies to a number of potentially dangerous side effects, including bone fractures and chronic kidney disease. A new case study, however, suggests that there may be other concerns, namely, “rhabdomyolysis”, a skeletal muscle disorder.

The doctors report on a single case where a patient developed the serious disorder after just one intravenous dose of Nexium (esomeprozole).

 Patient Treated with Nexium Develops Rhabdomyolysis

The patient in this case was a 45-year old man who went to the emergency room because of persistent lower chest pain. He had been previously diagnosed with diabetes and coronary heart disease, but had stopped taking diabetes medications about one month before. He was still taking medication for coronary heart disease.

Doctors ran a number of tests and found no initial abnormalities, so they administered 40 mg of Nexium to help control his chest pain. Twelve hours later, the patient complained of abrupt severe right buttock pain. Doctors checked and found an area where the muscles had become swollen and very tender. A blood test showed that his levels of creatine kinase (an enzyme associated with muscle damage) and levels of lactate dehydrogenase (an enzyme associated with tissue damage) were both elevated.

Doctors then performed a bone scan, and found that the patient had developed rhabdomyolysis.

What is Rhabdomyolysis?

Rhabdomyolysis is a condition that causes muscle cells to break down. The muscle fibers become damaged and die, releasing a protein called “myoglobin” into the bloodstream. This protein can be harmful to the kidneys, and without treatment, rhabdomyolysis can lead to kidney damage and even kidney failure.

Symptoms of this disorder usually include muscle pain and cramps, difficulty moving the arms or legs, abdominal pain, fever, nausea or vomiting, confusion, rapid heart rate, and dark red or brown urine.

The condition can be caused by medications, including antipsychotics and statins, particularly when given in high doses. This new evidence suggest that it may also be caused by intravenous administration of PPIs like Nexium. Other causes may include extreme muscle strain, the use of illegal drugs, crush injuries, viral and bacterial infections, muscle diseases, seizures, and prolonged immobilization.

Doctors usually diagnose the condition as they did in this case, by measuring levels of creatine kinase, an enzyme found in muscles, and myoglobin.

How is Rhabdomyolysis Treated?

Early treatment can cure the condition without damage to the kidneys. That’s what happened in this case—doctors helped flush out the drug with increased hydration and fluids containing bicarbonate, which helps get rid of the myoglobin. During follow-up the patient showed no evidence of recurrence.

The doctors warned that “single-dose intravenous administration of esomeprazole can induce rhabdomyolysis.”

More serious cases of the disorder may require  treatment medications or even kidney dialysis.

This case report raises the question of whether Nexium and other PPI medications should be added to the list of drugs that can cause rhabdomyolysis. Other drugs on the list include Ritalin, Adderall, and Dexedrine.