Chronic heartburn can cause a variety of devastating conditions like cancer, but the drugs that treat this condition present risks of their own. Called Proton Pump Inhibitors (PPIs), these drugs work to relieve heartburn by reducing the amount of acid in the stomach; but an increasing number of studies found the medications have dangerous side effects.

A recent study presented at ASN Kidney Week in Chicago found patients taking heartburn drugs like PPIs have an increased risk of developing kidney stones. Examining information from more than 187,000 patients, researchers found PPIs users have a 12% increased chance of developing kidney stones over patients who did not take any PPIs.

Kidney stones are hard deposits of minerals and acid salts that stick together in urine. While kidney stones do pass through the body, they are generally extremely painful. In some instances, the stones need to be broken up before they can pass through the urinary tract.

While kidney stones are not usually a life-threatening condition, PPIs can cause a variety of other more serious side effects. The most dangerous side effect to heartburn patients is the development of chronic kidney disease, or the gradual loss of kidney function over time. If left untreated, patients with chronic kidney disease might require dialysis treatment or a complete kidney transplant.

Other side effects caused by PPIs include infertility in men, dementia in elderly patients, osteoporosis, an increased stroke risk, weakened immune systems, and heart complications when taken with antibiotics.

Millions of Americans take PPIs each year, and many are not aware of the risks. PPIs like Nexium and Prilosec generate billions of dollars in sales and are available in both prescription strength and over-the-counter dosages. The widespread use of these drugs quickly spawned dozens of lawsuits alleging manufacturers failed to warn of the risks. While these lawsuits are in the very early stages, it likely the litigation will grow to huge numbers.