Prevacid (lansoprazole) is marketed as a proton pump inhibitor (PPI) drug that is either prescribed or available as an over-the-counter (OTC) medication. It is used for heartburn and acid reflux treatment and works by blocking an enzyme in the wall of the stomach that produces acid. If acid is produced in too great a quantity, it can migrate back up into the throat and cause gastroesophageal reflux disease (GERD). It can also cause Zollinger-Ellison syndrome, which makes tumors in the pancreas or duodenum. Although generally thought to be safe, Prevacid does have some side effects that may show up after being on the medication too long.
No Systemic Side Effects
No significant long term side effects were found to the human endocrine system, reproductive system, lymph system, central nervous system or circulatory system after nearly five years of treatment, according to the National Institutes for Health (NIH). Other areas of concern where no systemic effects of Prevacid occurred include the renal and hepatic systems in humans. Prevacid had no effect on vision after long-term use either.
Infectious Diarrhea Possible
Since Prevacid blocks the production of acid in the stomach, which would normally limit bacteria production, one side effect from using Prevacid too long could be infectious diarrhea, according to Ray Sahelian, M.D. as reported on his website. However, he says, "long-term usage is difficult to define and most patients take proton-pump inhibitors non-continuously."
Other Possible Side Effects
Other side effects include the possibility that the drug may be a cancer-causing agent. Dr. Sahelian says it could also contribute to hip fractures. But most likely, being on the drug too long may cause infections from H. pylori bacteria (Helicobacter pylori) and can also cause stomach polyps after long-term use.
Pancreatic and Renal Damage in Rats
Rats given Prevacid for their entire lives showed some damage to the pancreas and renal system, according to the NIH. It also states the thymus gland became enlarged in some of the rats; however, it isn't known if similar side effects may arise with humans.
