A nurse in a primary care clinic is caring for a 28-year-old female client who was diagnosed with epilepsy during childhood. Click to highlight the findings that require immediate follow-up as contraindications to the prescribed prescription (phenytoin). To deselect a finding, click on the finding again. Findings Temperature: 36.4°C (97.6°F), oral. Client is a vegetarian and takes a multivitamin daily. Client reports having three to four alcoholic beverages a couple times per week. Last menstrual period was three months ago. Client takes diazepam as needed for anxiety. Abdomen soft, nontender, normoactive bowel sounds in all 4 quadrants. Client has full range of motion and is able to maintain flexion against resistance in all four extremities.

Choice A rationale: A temperature of 36.4°C (97.6°F) is within the normal oral temperature range (36.1°C to 37.2°C). Phenytoin does not have contraindications related to normal body temperature. Fever or hypothermia may influence drug metabolism in extreme cases, but this client’s temperature is stable and does not interfere with phenytoin pharmacokinetics or safety. Therefore, this finding does not require immediate follow-up as it poses no contraindication to phenytoin therapy. Choice B rationale: Being vegetarian and taking a multivitamin daily is not a contraindication to phenytoin. However, phenytoin may interfere with the absorption of certain vitamins, particularly folic acid, vitamin D, and vitamin K. While vegetarians may have lower dietary intake of some nutrients, this is not an absolute contraindication. Monitoring for deficiencies is prudent, but this finding does not necessitate immediate follow-up or discontinuation of phenytoin. Choice C rationale: Alcohol consumption significantly affects phenytoin metabolism. Chronic alcohol use induces hepatic enzymes, reducing phenytoin levels and risking seizure recurrence. Conversely, acute alcohol intake inhibits metabolism, increasing phenytoin levels and toxicity risk. This bidirectional interaction complicates seizure control and increases adverse effects such as ataxia, nystagmus, and CNS depression. Therefore, regular alcohol use requires immediate follow-up to assess risk and reinforce abstinence during phenytoin therapy3. Choice D rationale: A missed menstrual period for three months raises concern for possible pregnancy. Phenytoin is teratogenic and associated with fetal hydantoin syndrome, including craniofacial anomalies and developmental delays. It also reduces the efficacy of hormonal contraceptives by inducing CYP450 enzymes. Therefore, pregnancy must be ruled out before initiating phenytoin, and non-hormonal contraception should be advised. This finding requires immediate follow-up due to potential fetal harm5. Choice E rationale: Diazepam, a benzodiazepine, interacts with phenytoin by altering its serum concentration. Diazepam may increase or decrease phenytoin levels unpredictably, leading to toxicity or subtherapeutic effects. Symptoms of phenytoin toxicity include nystagmus, ataxia, and confusion. Co-administration requires close monitoring of phenytoin levels and possible dose adjustments. This interaction is clinically significant and warrants immediate follow-up to ensure safe concurrent use7. Choice F rationale: A soft, nontender abdomen with normoactive bowel sounds is a normal physical finding and does not interfere with phenytoin absorption or metabolism. Gastrointestinal status is relevant if there is malabsorption or vomiting, which could affect oral drug bioavailability. However, in this case, the GI exam is unremarkable and does not present a contraindication to phenytoin therapy. No follow-up is required for this finding. Choice G rationale: Full range of motion and the ability to maintain flexion against resistance in all extremities indicate intact neuromuscular function. Phenytoin does not have contraindications related to baseline muscle strength or motor function. Neurological assessment is important for monitoring phenytoin toxicity, but normal strength and coordination do not require follow-up. This finding supports the client’s current functional status and is not a contraindication.