A nurse is caring for a client who is postoperative following hip arthroplasty. The nurse should anticipate which of the following medications for this client?

Choice A reason: Blood pressure 160/94 mm Hg is not a reason to withhold atenolol, as it is a beta-blocker that lowers blood pressure and reduces the workload of the heart. Atenolol is indicated for hypertension, angina, and arrhythmias. The nurse should administer atenolol as prescribed, unless the blood pressure is too low (hypotension).

Choice B reason: Heart rate 46/min is a reason to withhold atenolol, as it is a sign of bradycardia (slow heart rate), which can be a side effect of atenolol. Atenolol can decrease the heart rate by blocking the beta-1 receptors in the heart. The nurse should withhold atenolol if the heart rate is below 60 beats per minute or above 100 beats per minute, and report the finding to the provider.

Choice C reason: Oxygen saturation 95% is not a reason to withhold atenolol, as it is a normal value that indicates adequate oxygenation of the blood. Atenolol does not affect the oxygen saturation or the respiratory function. The nurse should monitor the oxygen saturation regularly, and report any signs of hypoxia (low oxygen level).

Choice D reason: Respiratory rate 18/min is not a reason to withhold atenolol, as it is a normal value that indicates normal breathing. Atenolol does not affect the respiratory rate or the respiratory function. The nurse should monitor the respiratory rate regularly, and report any signs of dyspnea (difficulty breathing).

Choice A reason: Taking the medication in the morning is not the correct instruction. Simvastatin is a statin drug that lowers cholesterol levels by inhibiting the enzyme that produces cholesterol in the liver. The liver produces more cholesterol at night, so simvastatin is more effective when taken in the evening or at bedtime.

Choice B reason: Avoiding grapefruit juice is the correct instruction. Grapefruit juice can increase the blood levels of simvastatin and cause serious side effects such as muscle damage, liver damage, and kidney failure. Grapefruit juice inhibits the enzyme that metabolizes simvastatin in the intestine, leading to higher concentrations of the drug in the bloodstream.

Choice C reason: Monitoring for ringing in the ears is not the correct instruction. Ringing in the ears, or tinnitus, is not a common or serious side effect of simvastatin. However, some other medications that lower cholesterol, such as niacin and gemfibrozil, can cause tinnitus. The client should report any unusual or persistent symptoms to the prescriber.

Choice D reason: Expecting brown-colored urine is not the correct instruction. Brown-colored urine, or hematuria, is not a normal or expected side effect of simvastatin. However, it may indicate a serious condition such as rhabdomyolysis, which is a rare but life-threatening complication of statin therapy. Rhabdomyolysis is the breakdown of muscle tissue that releases a protein called myoglobin into the bloodstream. Myoglobin can damage the kidneys and cause brown-colored urine. The client should seek immediate medical attention if they notice any signs of rhabdomyolysis, such as muscle pain, weakness, fever, or dark urine.