JT, a 23-year-old male graduate student with a 3-year history of complex partial seizures with occasional secondary generalization, presents to your pharmacy disease management clinic for adjustment of his antiseizure regimen. Initially controlled on valproate, a 25-kg weight gain over 28 months prompted a change to lamotrigine. Lamotrigine was slowly titrated upward over several months. A week ago, just as he reached a maintenance dose of 200 mg bid, he developed erythema multiforme and was hospitalized temporarily because it appeared as if it was progressing to Stevens-Johnson syndrome. The drug was discontinued and high-dose corticosteroids started. No mucous membrane lesions developed and he was discharged 9 days ago on carbamazepine 100 mg bid. The neurologist recommended a slow upward titration to approximately 8 to 10/mg/kg or a serum level of about 8 μg/mL. Carbamazepine serum level drawn yesterday was 1.1 μg/mL (target range 5 to 12 mcg/ml).
a. List six questions you would ask/laboratory tests you would order or physical examinations you would perform to evaluate the efficacy and potential adverse effects of carbamazepine in JT?
b. During the visit, JT revealed that he had had no generalized seizures. However, his mother thought he might have had a brief spell 2 days after leaving the hospital consisting of just some walking around in a daze. He feels it was the carbamazepine that made him “spaced out.” JT says that spaced out feeling has gotten better the last 2 days. JT’s cerebellar examination as well as a complete neurological screening examination were normal. Discuss the impact of your findings and your plan.
