Doctors say negative interactions with medications happen more than you may think, leading to a quarter of a million hospitalizations each year in the United States.

About 36% of Americans take at least three prescription medications, according to the Centers for Disease Control and Prevention.

One thing doctors have to consider when prescribing a new medication is if it will interact with any drugs the patient is already taking.

“If the coordination of care is not done well, a drug-drug interaction could be overlooked,” Michael Weiner, professor of medicine at Indiana University of Medicine, said.

When medications interact negatively, it could change the effectiveness of the drug, and be dangerous for the patient.

“These drug interactions can have a wide range of effects that can range from mild to deadly,” Weiner said.

Weiner said patients can help by doing three things.

“Know the drugs you're taking and why you're taking them, that's first,” Weiner said. “Second, bring the drugs to your doctor's visits, and third, ask your health care professionals if any of these drugs will interact with each other."

Doctor Weiner says if you start a new medication or your doctor changes the dosage of one you are already taking, look for any unusual symptoms.

If you experience any, report them to your doctor quickly.

Watch the video above for the full story.