Sodium channel blocking antiepileptics — MCQs

A 7-year-old boy is brought to the physician because of spells of unresponsiveness and upward rolling of the eyes for 2 months. The episodes start abruptly and last a few seconds. During that time he does not hear anyone’s voice or make any purposeful movements. When the episodes end, he continues what he was doing before the spell. He does not lose his posture or fall to the ground. Episodes occur multiple times during the day. Physical examination shows no abnormal findings. An EEG following hyperventilation shows 3 Hz spike-and-slow-wave discharges. Which of the following is the most appropriate pharmacotherapy at this time?

A 24-year-old man is brought to the emergency department because of violent jerky movements of his arms and legs that began 30 minutes ago. His father reports that the patient has a history of epilepsy. He is not responsive. Physical examination shows alternating tonic jerks and clonic episodes. There is blood in the mouth. Administration of intravenous lorazepam is begun. In addition, treatment with a second drug is started that alters the flow of sodium ions across neuronal membranes. The second agent administered was most likely which of the following drugs?

A 6-year-old boy is brought to the physician because of a 2-week history of frequent episodes of unresponsiveness. During these episodes, he stares blankly, rhythmically nods his head, and does not respond to verbal stimulation for several seconds. Hyperventilation for 30 seconds precipitates an episode of unresponsiveness and head nodding that lasts for 7 seconds. He regains consciousness immediately afterward. An electroencephalogram shows 3-Hz spikes and waves. Which of the following best describes the mechanism of action of the most appropriate pharmacotherapy for this patient's condition?

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 30-year-old female with a history of epilepsy becomes pregnant. Her epilepsy has been well controlled by taking a medication that inhibits GABA transaminase and blocks voltage-gated sodium and calcium channels. Her obstetrician informs her that her epilepsy medication has been shown to have teratogenic effects. Of the following, which teratogenic effect is this woman's medication most likely to cause?

A neuroscientist is delivering a lecture on the electrophysiology of the brain. He talks about neuroreceptors which act as ion channels in the neurons. He mentions a specific receptor, which is both voltage-gated and ligand-gated ion channel. Which of the following receptors is most likely to be the one mentioned by the neuroscientist?

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 45-year-old homeless man presents to the emergency department with a 1-week history of an intensely pruritic, red rash on his hands, wrists, and finger webs. The itching is worse at night. Physical examination reveals small, erythematous papules and burrows. A topical drug with which of the following mechanisms of action is most likely to be effective in treating this condition?

A 56-year-old man comes to the physician for a follow-up examination. One month ago, he was diagnosed with a focal seizure and treatment with a drug that blocks voltage-gated sodium channels was begun. Today, he reports that he has not had any abnormal body movements, but he has noticed occasional double vision. His serum sodium is 132 mEq/L, alanine aminotransferase is 49 U/L, and aspartate aminotransferase is 46 U/L. This patient has most likely been taking which of the following drugs?

A 75-year-old man with a seizure disorder is brought to the emergency department by a friend because of progressive confusion over the past two weeks. He is unable to provide any history. His vital signs are within normal limits. He appears lethargic and is only oriented to person. Oral mucosa is moist. There is no jugular venous distention. A basic metabolic panel shows a serum sodium concentration of 115 mEq/L but is otherwise normal. Serum osmolality is low and antidiuretic hormone level is elevated. X-ray of the chest shows no abnormalities. Which of the following is the most likely cause of this patient’s hyponatremia?