Antiepileptic drug interactions — MCQs

A 57-year-old man calls his primary care physician to discuss the results of his annual laboratory exams. The results show that he has dramatically decreased levels of high-density lipoprotein (HDL) and mildly increased levels of low-density lipoprotein (LDL). The physician says that the HDL levels are of primary concern so he is started on the lipid level modifying drug that most effectively increases serum HDL levels. Which of the following is the most likely a side effect of this medication that the patient should be informed about?

A 58-year-old man comes to the physician because of severe muscle aches and fatigue for 3 days. Last week he was diagnosed with atypical pneumonia and treated with clarithromycin. He has hyperlipidemia for which he takes lovastatin. Physical examination shows generalized tenderness of the proximal muscles in the upper and lower extremities. Serum studies show an elevated creatine kinase concentration. This patient's current symptoms are most likely caused by inhibition of which of the following hepatic enzymes?

A 25-year-old woman presents to her college campus clinic with the complaint of being unable to get up for her morning classes. She says that, because of this, her grades are being affected. For the past 6 weeks, she says she has been feeling depressed because her boyfriend dumped her. She finds herself very sleepy, sleeping in most mornings, eating more snacks and fast foods, and feeling drained of energy. She is comforted by her friend’s efforts to cheer her up but still feels guarded around any other boy that shows interest in her. The patient says she had similar symptoms 7 years ago for which she was prescribed several selective serotonin reuptake inhibitors (SSRIs) and a tricyclic antidepressant (TCA). However, none of the medications provided any long-term relief. She has prescribed a trial of Phenelzine to treat her symptoms. Past medical history is significant for a long-standing seizure disorder well managed with phenytoin. Which of the following statements would most likely be relevant to this patient’s new medication?

A case-control study is conducted to investigate the association between the use of phenytoin during pregnancy in women with epilepsy and the risk for congenital malformations. The odds ratio of congenital malformations in newborns born to women who were undergoing treatment with phenytoin is 1.74 (P = 0.02) compared to newborns of women who were not treated with phenytoin. Which of the following 95% confidence intervals is most likely reported for this association?

A 19-year-old man with a history of generalized tonic-clonic seizures comes to the physician for a routine health maintenance examination. He is a known user of intravenous cocaine. His vital signs are within normal limits. Physical examination shows multiple hyperpigmented lines along the forearms. Oral examination shows marked overgrowth of friable, ulcerated gingival mucosa. Which of the following is the most likely cause of this patient's oral examination findings?

A 20-year-old woman presents to the emergency department with painful abdominal cramping. She states she has missed her menstrual period for 5 months, which her primary care physician attributes to her obesity. She has a history of a seizure disorder treated with valproic acid; however, she has not had a seizure in over 10 years and is no longer taking medications for her condition. She has also been diagnosed with pseudoseizures for which she takes fluoxetine and clonazepam. Her temperature is 98.0°F (36.7°C), blood pressure is 174/104 mmHg, pulse is 88/min, respirations are 19/min, and oxygen saturation is 98% on room air. Neurologic exam is unremarkable. Abdominal exam is notable for a morbidly obese and distended abdomen that is nontender. Laboratory studies are ordered as seen below. Serum: hCG: 100,000 mIU/mL Urine: Color: Amber hCG: Positive Protein: Positive During the patient's evaluation, she experiences 1 episode of tonic-clonic motions which persist for 5 minutes. Which of the following treatments is most appropriate for this patient?

A 28-year-old woman comes to the emergency department because of a 2-day history of dark urine, increasing abdominal pain, and a tingling sensation in her arms and legs. She has a history of epilepsy. Her current medication is phenytoin. She is nauseated and confused. Following the administration of hemin and glucose, her symptoms improve. The beneficial effect of this treatment is most likely due to inhibition of which of the following enzymes?

A 55-year-old male presents to his primary care physician for a normal check-up. He has a history of atrial fibrillation for which he takes metoprolol and warfarin. During his last check-up, his international normalized ratio (INR) was 2.5. He reports that he recently traveled to Mexico for a business trip where he developed a painful red rash on his leg. He was subsequently prescribed an unknown medication by a local physician. The rash resolved after a few days and he currently feels well. His temperature is 98.6°F (37°C), blood pressure is 130/80 mmHg, pulse is 95/min, and respirations are 18/min. Laboratory analysis reveals that his current INR is 4.5. Which of the following is the most likely medication this patient took while in Mexico?

A 50-year-old woman presents with acute onset fever and chills for the past hour. She mentions earlier in the day she felt blue, so she took some St. John’s wort because she was told by a friend that it helps with depression. Past medical history is significant for hypertension, diabetes mellitus, and depression managed medically with captopril, metformin, and fluoxetine. She has no history of allergies. Her pulse is 130/min, the respiratory rate is 18/min, the blood pressure is 176/92 mm Hg, and the temperature is 38.5°C (101.3°F). On physical examination, the patient is profusely diaphoretic and extremely irritable when asked questions. Oriented x 3. The abdomen is soft and nontender with no hepatosplenomegaly. Increased bowel sounds are heard in the abdomen. Deep tendon reflexes are 3+ bilaterally and clonus is elicited. The sensation is decreased in the feet bilaterally. Mydriasis is present. Fingerstick glucose is 140 mg/dL. An ECG shows sinus tachycardia but is otherwise normal. Which of the following is the most likely cause of this patient’s condition?

A 63-year-old man with high blood pressure, dyslipidemia, and diabetes presents to the clinic for routine follow-up. He has no current complaints and has been compliant with his chronic medications. His blood pressure is 132/87 mm Hg and his pulse is 75/min and regular. On physical examination, you notice that he has xanthelasmas on both of his eyelids. He currently uses a statin to lower his LDL but has not reached the LDL goal you have set for him. You would like to add an additional medication for LDL control. Of the following, which statement regarding fibrates is true?