CLAYTON, Mo. -- A 35-year-old Missouri mother was charged Friday for felony child endangerment after allegedly poisoning her 9-year-old son intentionally with prescription drugs, KTVI reported.

The mother and son live in the northwest Missouri city of Meadville, it was in St. Louis that doctors discovered the alleged overdoses.

Rachel Kinsella had been taking her son to the St. Louis Children's Hospital to be treated for epilepsy, but doctors discovered that he was falling seriously ill over and over again from a dangerous combination of two prescription drugs, given to him over the course of about a year.

Prosecutors say the mother was able to poison him for so long because she was taking to him to two different doctors, one in St. Louis and the other in Kansas City at Children's Mercy. Neither doctor knew about the other, which was Kinsella's attempt to hide the abuse, they said.

"The child, when he would present at the hospital in very serious condition, would get much better while he was there," St. Louis County Prosecutor Bob McCulloch said. "When he was returned to her custody he got sick again. And apparently was being treated by two different doctors, apparently unknown to each other."

The child was put into protective custody in January and is now living with his paternal grandparents. He is "thriving," according to KTVI, and has no lasting effects from the overdoses.

Kinsella's lawyer Greg Smith denies the allegation and says the mother wants her son back, saying "...we are prepared to fight the good fight."

Smith denies that Kinsella exhibited a case of Munchausen by proxy, a condition in which a mother purposely makes a child ill to attract attention to herself. Court documents say she admits to giving her son the wrong medication by accident "on occasion."

Missouri is the only state in the U.S. without a prescription medicine database, which would allow doctors and pharmacists to see every medication that has been prescribed to a patient.

Kinsella has been released from the St. Louis County Jail after paying 10 percent of her $50,000 bond.