A 29-year-old woman presents to her primary care physician for a regular yearly checkup. She has a history of a seizure disorder and has been taking an antiseizure medication for 8 years. She is also taking an oral contraceptive. She is in good health but complains that her gums seem to be overgrowing her teeth. Which of the following medications is likely responsible for her chief complaint?

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Phenytoin and carbamazepine are antiepileptic drugs with a shared mechanism: they stabilize neuronal membranes by preventing sodium influx through fast sodium channels, reducing excitability and controlling seizures, particularly in partial and tonic-clonic types. Both induce hepatic cytochrome P450 enzymes, accelerating metabolism of other drugs, not inhibiting it. Phenytoin exhibits zero-order elimination at high doses due to enzyme saturation, while carbamazepine follows first-order kinetics, so this isn't a shared trait. They reduce the efficacy of oral contraceptives by inducing their metabolism, not enhancing them. Safety in pregnancy is questionable, with both linked to teratogenicity (e.g., fetal hydantoin syndrome). The sodium channel blockade is the fundamental property uniting their therapeutic effects, making it the key characteristic they share, critical to their role in epilepsy management.

Correct Answer: A

Rationale: Cefotaxime is a third-generation cephalosporin antibiotic commonly used to treat bacterial infections post-surgery. One of its most significant and frequent adverse effects is disruption of the gastrointestinal flora, which can lead to diarrhea, including potentially severe conditions like Clostridioides difficile-associated diarrhea. This makes monitoring for diarrhea a critical nursing action, as it can indicate a serious complication requiring immediate intervention. While headache, constipation, and tachycardia can occur with various medications, they are less commonly associated with cefotaxime compared to diarrhea. Headache might suggest a neurological issue or dehydration, constipation could relate to immobility post-surgery rather than the drug itself, and tachycardia might indicate an allergic reaction or systemic issue, but these are not the primary concerns with this antibiotic. Diarrhea, however, directly correlates with cefotaxime's impact on gut microbiota, making it the priority observation for adverse effects in this scenario, thus supporting choice A as the correct answer.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.