The Florida Highway Patrol says his car was stopped around 6 p.m. Wednesday for weaving and nearly causing an accident.
Cassidy told a trooper that he had a glass of wine at lunch and a hydrocodone pill at 3:30 p.m. Troopers reported finding a half-empty bottle of bourbon in the back seat.
The FHP says Cassidy failed a field sobriety test and two breath tests. Cassidy posted $350 bail and was released from jail early Thursday.
His spokeswoman, Jo-Ann Geffen, told TMZ he admits taking a pain pill and being tired from attending a funeral, but insists he was not drunk. She did not immediately return an e-mail from The Associated Press.