A man spiked a cup of coffee with a sedative after arguing with a doctor's receptionist, a court has heard.
Hugh McDermott, 42, put Diazepam into Lynne Moore's coffee at The Willows Surgery in Downend, Bristol, last July.
During police interview, he told officers he spiked Ms Moore's drink because "she was looking miserable".
Previously, McDermott, of Selbrooke Crescent, Oldbury Court, pleaded guilty to administering a noxious substance with intent to injure or annoy.
Judge Julian Lambert adjourned sentencing to Bristol Crown Court on July 1 for pre-sentence reports.
Sarah Hurrion, prosecuting, told Bristol Crown Court that McDermott, had visited the city surgery to discuss the details of his prescription.
Acting suspiciously
She said that he had become "agitated" and started "banging on the reception desk" after talking to Mrs Moore.
The receptionist had walked away from the desk when another patient noticed McDermott acting suspiciously.
Ms Hurrion said: "He pulled pills out of his pocket and with a smug expression on his face dropped a number of tablets into a cup of coffee."
The patient warned the receptionist what had happened and police were called.
Forensic examinations revealed a quantity of Diazepam present in the drink but they could not determine the quantity.