Final answer:
The nurse practitioner would suspect an adverse reaction to Digoxin (Lanoxin) based on the patient's symptoms of nausea, vomiting, abdominal pain, and visual changes, and would advise the patient to follow-up with their cardiologist for evaluation and management.
Step-by-step explanation:
The symptoms of nausea and vomiting, abdominal pain, and visual changes in a 41 year old patient prescribed Digoxin (Lanoxin) suggest that the patient may be experiencing digoxin toxicity. These symptoms are known side effects of Digoxin when the levels in the bloodstream are too high, and they can be potentially dangerous. The appropriate course of action for the nurse practitioner would be option d: to send the patient to the emergency room for immediate evaluation. This is crucial as digoxin toxicity can lead to severe cardiac problems and other significant health issues and needs to be addressed promptly.