A nurse is teaching a client who takes warfarin daily. Which of the following statements by the client indicates a need for further 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: 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.