The Physician Has Ordered Phenobarbital (Luminal)100 Mg Three Times a Day

The physician has ordered phenobarbital (Luminal) 100 mg three times a day for a patient with seizures.To help the nurse develop an appropriate care plan for this patient,which best describes the action of this drug in the body?

A) It will increase urination for 2 hours after ingestion.
B) It will cause severe thirst and dryness of the mucous membranes.
C) It has a long duration and a sedative effect on the brain.
D) It will lower the seizure threshold.