A 29-year-old woman presents with dysuria and frequency four weeks after giving birth. The antenatal period and delivery were unremarkable. She is exclusively breastfeeding her child at the current time. Abdominal examination is unremarkable and she is apyrexial. A urine dipstick shows blood +, protein +, leucocytes +++ and nitrates positive. What is the most appropriate management?
Co-amoxiclav + metronidazole