A nurse is teaching a client who has a new prescription for transdermal nitroglycerin to treat angina pectoris. Which of the following instructions should the nurse include in the teaching?

Choice A reason: Ototoxicity is not a severe reaction to propranolol, but it may occur with some other medications, such as aminoglycosides, loop diuretics, or salicylates. Ototoxicity may damage the inner ear or the auditory nerve and cause hearing loss, tinnitus, or vertigo. The nurse should assess the client's medication history and monitor the client's hearing function.

Choice B reason: Hypokalemia is not a severe reaction to propranolol, but it may occur with some other medications, such as thiazide diuretics, corticosteroids, or insulin. Hypokalemia may cause muscle weakness, cramps, arrhythmias, or cardiac arrest. The nurse should advise the client to eat foods rich in potassium, such as bananas, oranges, or potatoes, and to have regular blood tests to check the electrolyte levels.

Choice C reason: Tachycardia is not a severe reaction to propranolol, but it may be a sign of overdose, withdrawal, or rebound effect. Propranolol is a beta-blocker that lowers the heart rate and blood pressure by blocking the effects of epinephrine and norepinephrine. Propranolol may cause bradycardia, not tachycardia, as a side effect. The nurse should monitor the client's vital signs and advise the client to take the medication as prescribed and not to stop it abruptly.

Choice D reason: Postural hypotension is a severe reaction to propranolol, as it may cause dizziness, fainting, or falls. Postural hypotension occurs when the blood pressure drops significantly when the client changes position, such as from lying to sitting or standing. Propranolol may cause postural hypotension by reducing the vascular tone and the cardiac output. The nurse should instruct the client to change position slowly and to report any symptoms of postural hypotension to the provider.

Choice A reason: Eating a green salad every night with dinner is not the statement that indicates a need for further teaching. This is a consistent and balanced dietary choice for the client, as long as the amount of vitamin K in the salad is not excessive or variable. Vitamin K is a nutrient that helps the blood to clot and can interfere with the action of warfarin, which is an anticoagulant that inhibits the formation of blood clots. The client should avoid sudden changes in their intake of vitamin K and inform the provider of any dietary modifications.

Choice B reason: Taking this medication at the same time each day is not the statement that indicates a need for further teaching. This is a correct and important instruction for the client, as it helps to maintain a steady and effective level of warfarin in the blood. Warfarin has a narrow therapeutic range and requires frequent monitoring and dose adjustment. The client should take the medication as prescribed and avoid missing or skipping doses.

Choice C reason: Starting to take ginger root to treat joint stiffness is the statement that indicates a need for further teaching. This is a risky and potentially harmful herbal supplement for the client, as it can interact with warfarin and increase its anticoagulant effect. Ginger root has antiplatelet and fibrinolytic properties, which can inhibit the formation of blood clots and enhance the breakdown of fibrin, a protein that stabilizes blood clots. Taking ginger root with warfarin can increase the risk of bleeding and bruising and alter the international normalized ratio (INR), which is a measure of the blood's clotting ability. The client should avoid taking ginger root and other herbal supplements without consulting the provider.

Choice D reason: Having the INR checked three weeks ago is not the statement that indicates a need for further teaching. This is a reasonable and appropriate frequency for the client, depending on their stability and response to warfarin therapy. The INR is a blood test that measures the time it takes for the blood to clot and indicates the effectiveness of warfarin. The target INR range for most clients is 2 to 3, but it may vary depending on the indication and the risk of bleeding. The client should have their INR checked regularly and follow the provider's orders and the protocol for dose adjustment.