Imagine taking a prescription drug and losing your fingerprints. It sounds like science fiction, but that's just one of the strange side effects some prescription drugs can cause.

A cancer patient traveling from Singapore to the United States was delayed by U.S. Customs for four hours when agents discovered the man's fingerprints were missing. The man's doctors said he was taking the drug Xeloda. Xeloda is used to treat certain cancers and can cause people's fingers and palms to peel. The issue was eventually cleared up, and the man was allowed to enter the U.S.

Local 4 Dr. Frank McGeorge reported other drugs can affect the color of your eyes or your skin. The glaucoma drops Xalatan can turn blue eyes into brown, and the common heart medicine amiodarone can turn your skin gray-blue, especially if you get too much sun.

McGeorge said other medications can affect the color of your urine. The muscle relaxant Robaxin or the bladder pain medicine Urised can make your urine appear blue or green. The antibiotic Rifampin, which is given to patients who have been exposed to meningitis, will turn urine, sweat, saliva, and tears a startling red-orange color. McGeorge said that side effect can be a real problem if it stains your contact lenses.

It's not only prescription medications you need to watch out for. McGeorge reported, in some people, Pepto Bismol can turn your tongue or your stool black.

Unusual side effects aren't limited to the physical. McGeorge said the sleep aid zolpidem, sold as Ambien, can get people in real trouble by causing amnesia. There are many reports of people talking on the phone, cooking, or even driving without any memory of their actions. The Parkinson's disease treatment, Mirapex, has been known to cause patients to develop addictive behaviors like gambling and compulsive eating.

McGeorge said not all strange side effects are bad. Some have actually been turned into money-makers for drug companies. Minoxidil was originally developed to treat high blood pressure, but doctors noticed that patients taking the drug grew extra hair. The drug is now sold as Rogaine. And who can forget Viagra? McGeorge that the little blue pill that's now famous for treating erectile dysfunction was originally developed as a heart medicine.