Each year, millions of people get sick from the medication that's supposed to make them better. But now, there's a new way to reduce the odds of having those negative side effects, and it comes down to genetics.
Nine-year-old Darcy is a curious little girl. She loves checking every nuance of her pet hermit crabs. But this typical little girl was anything but a year ago.
"She was a monster child. She threw temper tantrums. She yelled, screamed, didn't do anything. She just stopped functioning and just started throwing fits," Darcy's mom Sherry Whitehead said.
The problem was Darcy's epilepsy medication. Her doctor tried a new medicine that worked much better. But the whole episode could have been avoided with a new scientific concept called Pharmacogenetics.
Medicines are prescribed based on genetic matching.
Dr. Tracy Glauser is a Pediatric Neurologist at Children's Hospital Medical Center in Cincinnati, Ohio.
"Our current service examines four common genes that are responsible for the metabolism of 37 different drugs," Glauser said.
Dr. Tracy Glauser helped found the Genetic Pharmacology Service at Cincinnati Children's Hospital.
With a simple blood test, he can determine which medication is least likely to have bad side effects for the patient. It's critical information for doctors.
"In a study done in 1998, published in JAMA, 100,000 people a year died from adverse drug reactions."
And another two million patients, like Darcy, become ill from those reactions.
Fortunately for Darcy, she's back to her old self and doing much better in school. Her mother says her little girl is back.