When should a nurse delay the administration of metformin to a client?

The administration of metformin should be delayed in a client who is newly diagnosed with Type 1 diabetes mellitus (DM type 1) because this type of diabetes is characterized by insufficient insulin production due to autoimmune destruction of pancreatic beta cells. Metformin, which is an oral hypoglycemic agent typically used to treat Type 2 diabetes, primarily works by decreasing hepatic glucose production and improving insulin sensitivity. Since individuals with Type 1 diabetes require insulin therapy for glycemic control, starting metformin would not address the underlying insulin deficiency and could lead to inadequate management of blood glucose levels. Therefore, a nurse should assess the patient's therapeutic needs carefully before initiating any medication and consider that metformin is not indicated for those who require insulin, such as those with Type 1 diabetes.