Suffolk County District Attorney Daniel F. Conley today announced the indictment of two Dorchester parents who allegedly allowed their 2-year-old son and a neighbor’s 6-year-old boy to overdose on a drug used to treat heroin addiction.

The Suffolk County Grand Jury on March 10 indicted HECTOR BATISTA, Sr. (D.O.B. 3/21/61) and MARIA PEREZ (D.O.B. 9/12/65) on charges of unlawful possession of a Class B substance, reckless endangerment of a child, and two counts of assault and battery on a child causing serious bodily injury.

The charges stem from the children’s ingestion of Suboxone in the defendants’ Ballou Street home on the evening of Jan. 16. Neither defendant had a prescription for the drug, which is only available legally from a doctor.

“Young children sometimes have to depend on adults for protection from their own curiosity,” Conley said. “Allowing two children access to a powerful drug like this one isn’t just reckless – it’s potentially deadly.”

Authorities say the defendants didn’t take action when the children were playing near the dresser on which the pills were kept in a jewelry box, and that they didn’t notice their son was suffering from an overdose until his lips were purple and he had trouble breathing. By this time, the 6-year-old neighbor had returned to his mother’s residence.

The defendants allegedly flushed the remaining Suboxone down the toilet and called for help. A neighbor called 911 and emergency medical technicians transported the 2-year-old to Boston Medical Center. He remained on a ventilator for two days and required hospitalization for several additional days.

It was not until Jan. 17 that the defendants informed the 6-year-old neighbor’s mother of their son’s condition. That boy, who had been vomiting and ill, was also hospitalized.

Batista and Perez are expected to be arraigned Friday in the Magistrate’s Session of Suffolk Superior Court.