A 34-year-old man presents with throbbing pain and a localised fluctuant buccal swelling adjacent to tooth 46, which is non-vital with a periapical radiolucency. His temperature is 37.1 C, there is no trismus, no lymphadenopathy and no spread beyond the vestibule. He is otherwise well. According to current Australian therapeutic guidelines, what is the most appropriate management at this visit?