A nurse is caring for a client who is on warfarin therapy for atrial fibrillation. The client's INR is 5.2. Which of the following medications should the nurse prepare to administer?

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: Expecting to gain weight while taking this medication is not a correct instruction, as it may discourage the client from adhering to the treatment and may worsen the hypertension. Captopril is an angiotensin-converting enzyme (ACE) inhibitor that lowers the blood pressure by preventing the formation of angiotensin II, a potent vasoconstrictor. Captopril does not cause significant weight gain, but it may cause fluid retention or edema in some cases. The nurse should advise the client to monitor the weight daily and report any sudden or excessive increase to the provider.

Choice B reason: Not using salt substitutes while taking this medication is a correct instruction, as it may prevent the risk of hyperkalemia, a potentially life-threatening condition. Captopril may increase the potassium level in the blood by reducing the secretion of aldosterone, a hormone that regulates the sodium and potassium balance. Salt substitutes may contain potassium chloride, which may further elevate the potassium level. The nurse should advise the client to avoid salt substitutes and high-potassium foods, such as bananas, oranges, or tomatoes, and to have regular blood tests to check the electrolyte levels.

Choice C reason: Counting the pulse rate before taking the medication is not a necessary instruction, as it may not reflect the effect of the medication on the blood pressure. Captopril does not affect the heart rate significantly, but it may lower the blood pressure too much, especially in the first few weeks of treatment or after a dose increase. This may cause hypotension, dizziness, or fainting. The nurse should advise the client to monitor the blood pressure regularly and report any symptoms of hypotension to the provider.

Choice D reason: Taking the medication with food is not a correct instruction, as it may reduce the absorption and effectiveness of the medication. Captopril should be taken on an empty stomach, at least one hour before or two hours after a meal, to ensure optimal bioavailability. The nurse should advise the client to take the medication at the same time every day and to avoid skipping or doubling the doses.