The client prescribed ondansetron (Zofran) for persistent nausea and vomiting demonstrates understanding about his medication when he states:

Choice A reason: CT scan with contrast is an order that the nurse should question for the client who is taking metformin for hyperglycemia. Metformin is a medication that lowers the blood glucose level by decreasing the hepatic glucose production and increasing the insulin sensitivity¹. Metformin can cause a rare but serious complication called lactic acidosis, which is a buildup of lactic acid in the blood that can cause symptoms such as weakness, nausea, vomiting, or breathing problems. CT scan with contrast involves injecting iodinated contrast material into the bloodstream, which can affect the kidney function and increase the risk of lactic acidosis in patients taking metformin. The nurse should consult with the prescriber and the pharmacist about the need to stop metformin before and after the CT scan with contrast, and to monitor the kidney function and the blood glucose level of the client.

Choice B reason: Chest X-ray 1 view is not an order that the nurse should question for the client who is taking metformin for hyperglycemia. Chest X-ray is a diagnostic test that uses a small amount of radiation to produce images of the lungs, heart, and chest wall. Chest X-ray does not involve any contrast material or affect the kidney function or the blood glucose level. The nurse should follow the standard precautions and procedures for performing a chest X-ray, such as verifying the client's identity, checking for pregnancy, removing any metal objects, and positioning the client properly.

Choice C reason: V/Q scan is not an order that the nurse should question for the client who is taking metformin for hyperglycemia. V/Q scan is a diagnostic test that measures the ventilation and perfusion of the lungs, and can detect any abnormalities such as pulmonary embolism or chronic obstructive pulmonary disease. V/Q scan involves injecting a radioactive tracer into the bloodstream and inhaling a radioactive gas, which are then detected by a special camera. V/Q scan does not affect the kidney function or the blood glucose level. The nurse should follow the standard precautions and procedures for performing a V/Q scan, such as verifying the client's identity, checking for allergies, explaining the procedure, and monitoring the vital signs.

Choice D reason: Bilateral lower extremity ultrasound is not an order that the nurse should question for the client who is taking metformin for hyperglycemia. Bilateral lower extremity ultrasound is a diagnostic test that uses sound waves to produce images of the blood vessels in the legs, and can detect any abnormalities such as deep vein thrombosis or peripheral arterial disease. Bilateral lower extremity ultrasound does not involve any contrast material or affect the kidney function or the blood glucose level. The nurse should follow the standard precautions and procedures for performing a bilateral lower extremity ultrasound, such as verifying the client's identity, explaining the procedure, and applying a gel and a probe to the legs.

Choice A reason: Allergy is an immune mediated reaction to a substance that causes symptoms such as rash, itching, swelling, or anaphylaxis. It is not related to the duration or effectiveness of the medication. The patient does not report any signs of allergy to the opioids.

Choice B reason: Addiction is a chronic and compulsive disorder that involves seeking and using a substance despite harmful consequences. It is characterized by loss of control, craving, and impaired functioning. The patient does not show any signs of addiction to the opioids, such as increasing the dose, obtaining the medication illegally, or neglecting other responsibilities.

Choice C reason: Withdrawal is a syndrome that occurs when a substance is abruptly discontinued or reduced after prolonged use. It causes physical and psychological symptoms such as anxiety, agitation, sweating, nausea, or tremors. The patient does not experience any signs of withdrawal from the opioids, as they are still taking the medication as prescribed.

Choice D reason: Tolerance is a phenomenon that occurs when a substance loses its effectiveness over time due to repeated exposure. It requires higher doses or more frequent administration to achieve the same effect. The patient reports a sign of tolerance to the opioids, as they feel that the medication does not work as well anymore. The nurse should assess the patient's pain level, monitor the opioid dose, and consult with the prescriber about possible adjustments or alternatives.