A woman tried to kill her husband and teenage son by serving them milkshakes laced with lethal doses of prescription medication, authorities said. Both were hospitalized but recovered.

Mary Ellen Cannon (search), 46, was charged Monday with five felony counts, including attempted murder and poisoning, Oakland County prosecutor Deborah Carley said. The motive was unclear, authorities said.

Authorities say Cannon apparently ground up her own medication to put into the fast food restaurant milkshakes she served to Richard Shaw, 57, and Ian Shaw, 13, on Oct. 26.

Richard Shaw collapsed and went into a coma and the boy became ill later, Carley said. The husband was hospitalized for 11 days and Ian for three.

Tests on the milkshakes detected lethal doses of prescription medication for pain, sleep disorders, panic attacks and blood pressure regulation, authorities said.

Cannon, who was being held on a probation violation for an unrelated charge, was scheduled to be arraigned on the new charges Tuesday. If convicted, she could be sentenced to up to life in prison.