Final answer:
For a patient with type 1 diabetes mellitus experiencing a seizure due to hypoglycemia, glucagon should be administered to increase blood glucose levels and stop the seizure.
Step-by-step explanation:
The patient with type 1 diabetes mellitus who is having a seizure due to hypoglycemia should be administered glucagon. Glucagon is a hormone that raises blood glucose levels, and it is the immediate treatment for severe hypoglycemia, which is characterized by low blood sugar levels leading to seizures or unconsciousness.
In contrast, insulin is used to lower high blood sugar levels, which means administering insulin during hypoglycemia could worsen the patient's condition. Anticonvulsants like diazepam may be given to manage ongoing seizures, but they do not address the underlying cause of hypoglycemia in diabetes. Therefore, glucagon is the medication to anticipate for stopping a seizure due to hypoglycemia in a patient with type 1 diabetes.