Police charged Jennifer O'Bryan, 1723 Wayne St., with one count of endangering children after her son, Keelan, was taken to Southern Ohio Medical Center's emergency room.
It was the third time the child has been brought to the hospital in the past seven months after ingesting drugs, according to police.
The time of O'Bryan's arrest is listed as 5:41 a.m.
The child was displaying signs of extreme agitation and bizarre behavior, police say.
O'Bryan told police she had no idea how the child got the drugs. A search of her house turned up no illegal drugs.
The child is prescribed to take Tanaphad, and police said the child may have taken more than the dosage amount.
Dr. Martin Hajjar said the boy would have had to consume nearly a whole bottle to display the signs he was displaying.
Benadryl was found in the child's system on one occasion that he was brought to the hospital.
A type of amphetamine found in Stackers - a dietary supplement - was detected in his system the second time.
For that reason, police are accusing O'Bryan of neglect.
Police also said O'Bryan works odd hours as a lab technician at SOMC, which has led to exhaustion.
The Scioto County Children Services Department placed Keelan and another son, Braden, 2, into the care of O'Bryan's husband, Dennis O'Bryan, pending a court decision on the matter.
Tests for drugs in Braden's system were negative.
A man identifying himself as Jennifer O'Bryan's father said he would forward a message from the Portsmouth Daily Times seeking comment.
He said O'Bryan is estranged from her husband.
JEFF BARRON can be reached at (740) 353-3101, ext. 236.