Priscilla Tabarez, 20, called police Wednesday night to report her son had eaten the drug. She was arrested along with the child's father Daniel Sanchez, 26.
The woman's 18-year-old brother was also at the house at the time and was arrested for felony child endangerment.
Police say further investigation may lead to drug charges as well. Firefighters treated the little boy -- who was then taken to a hospital.
Gregg Meyer, Atascadero Police said, "Unfortunately this a case where you have a very young child who was exposed to a dangerous narcotic and fortunately he is now safe and the parents are in custody."
Investigators say the baby is now out of the hospital and in protective custody.