MRCP2-4636

An 80-year-old man has completed treatment for community-acquired pneumonia and is awaiting a package of care before discharge. He has a medical history of hypertension, ischaemic heart disease, type 2 diabetes, and advanced chronic kidney disease. The patient complains of severe pain in his left foot, which is swollen, erythematous, and hot to touch. His latest blood results show elevated creatinine levels. What would be the most appropriate treatment to commence given his likely diagnosis and co-morbidities?