Emergency and Toxicologymiddle twist
A 41-year-old man undergoes urgent debridement for a necrotising infection of the calf. Initial broad-spectrum treatment has been given, and deep tissue cultures grow Streptococcus pyogenes only. He remains haemodynamically stable after source control, with improving renal function and no immediate-type reaction to penicillin. Which one of the following is the most appropriate antimicrobial treatment now?