The State Pathologist for Northern Ireland, Prof Jack Crane, has told the Belfast coroner that the deaths of two women 18 months ago from a combination of the drugs morphine and ecstasy were the only known cases in the North.
The women were found in a bed in a house in east Belfast in October 1994.
The inquest heard that the morphine had been prescribed for the mother of one of four girls in the house and that the ecstasy was alleged to have been bought in a Belfast public house.
The coroner, Mr John Leckey, recorded the deaths of the two women - Irene Cross (33) of Ramore Green, in Larne, Co Antrim, and Gail McAllister (30) of Cherryville Street, Belfast, where the women were found as accidental.