Vocodin is a mild narcotic combined with acetominophen (generic Tylenol). The usual mix per tablet is 5 or 10 mg of hydrocodone with 500 mg of acetominophen. You probably have 5/500's, which is typical for dental prescriptions. The effects are generally mild drowsiness and a light euphoria, typical of narcotic pain relievers. Taking two is probably ok, but it may put you right to sleep.