You are working as a registered nurse in a medical ward, buddied with a nursing student, Alison. Your patient, Mr Trevor Johnson, informs you that he is due for his metformin. Alison asks you if you could explain the mechanism of action of metformin to her. Explain to Alison the possible explanation for the temporary suspension of Mr Johnson’s metformin and the potential complications if this drug was continued during the surgical procedure (coronary angiogram). Explain to Alison why more than one type of antidiabetic drug is often required. What advice would you give Mr. Johnson about his antidiabetic drug regimen and his concern about having a “hypo” at night?