What is the term used for a well understood drug model with which other drugs in its representative class are compared?

Choice A reason: Increased respiratory rate is not a sign of adverse reaction to metoprolol, but rather a normal response to hypoxia or distress. Metoprolol is a betablocker that can lower the heart rate and blood pressure, but it does not affect the respiratory rate directly.

Choice B reason: Bronchodilation is not a sign of adverse reaction to metoprolol, but rather a desired effect of asthma medications such as betaagonists or anticholinergics. Metoprolol is a betablocker that can block the beta receptors in the lungs, which can cause bronchoconstriction or narrowing of the airways. This is why metoprolol is contraindicated or used with caution in clients with asthma.

Choice C reason: Decreased sputum production is not a sign of adverse reaction to metoprolol, but rather a result of effective asthma management. Metoprolol is a betablocker that does not have any direct effect on the mucus secretion or inflammation in the lungs.

Choice D reason: Wheezing is a sign of adverse reaction to metoprolol, as it indicates bronchoconstriction or narrowing of the airways. Metoprolol is a betablocker that can block the beta receptors in the lungs, which can reduce the bronchodilation effect of beta agonists or other asthma medications. This can worsen the asthma symptoms and cause wheezing, coughing, dyspnea, or chest tightness. The nurse should monitor the client for these signs and report them to the prescriber immediately.

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.