A nurse is teaching a client with a new prescription for metformin (Glucophage). Which of the following findings should the nurse instruct the client to report as an adverse effect of metformin? (Select All That Apply.)

A. Metformin does not typically cause hypoglycemia because it works by decreasing hepatic glucose production and improving insulin sensitivity, not directly lowering blood sugar levels. B. Somnolence could indicate lactic acidosis, a rare but serious adverse effect of metformin that warrants immediate medical attention. C. Fluid retention is not a known adverse effect of metformin. Other medications, such as certain thiazolidinediones, are associated with this complication. D. Hyperglycemia is not a typical adverse effect of metformin; instead, it helps manage blood glucose levels in clients with type 2 diabetes mellitus.