Winehouse's UK rep Chris Goodman said that the 24-year-old singer was now in good spirits after spending a ''comfortable night'' in hospital.
''She had a bit of a scare yesterday because of a reaction to treatment,'' Contactmusic quoted Goodman, as saying.
''She was kept in overnight purely for observation,'' he added.
Winehouse's dad Mitch also said that his daughter is recovering well at home following the incident.
''(She is) right as rain. Amy's responded well to treatment. I must admit, it was very frightening last night, seeing her in that state. But she is with good friends, not hangers-on,'' he said.
''The doctors say it was an adverse reaction to prescription drugs or mixing them up. They are not sure exactly what happened and they have done tests on her. We are waiting for the results of the toxicology report later today,'' he added.