A nurse is reviewing laboratory results of a client who has atrial fibrillation and is taking warfarin. For which of the following results should the nurse notify 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.

Choice A reason: Taking this medication with food is not necessary, as lisinopril can be taken with or without food. Food does not affect the absorption or effectiveness of lisinopril.

Choice B reason: Facial swelling is not an expected effect of this medication, but a serious adverse reaction that indicates angioedema. Angioedema is a life-threatening condition that causes swelling of the face, tongue, throat, and airway. It requires immediate medical attention and discontinuation of lisinopril.

Choice C reason: Reporting a cough to the provider is an important instruction, as a cough is a common and annoying side effect of lisinopril. Lisinopril belongs to the class of angiotensin-converting enzyme (ACE) inhibitors, which can cause a dry, persistent, nonproductive cough. The cough may interfere with the client's quality of life and adherence to the medication. The provider may prescribe an alternative medication, such as an angiotensin II receptor blocker (ARB), to avoid the cough.

Choice D reason: Increasing the intake of potassium-rich foods is not advisable, as lisinopril can cause hyperkalemia (high potassium levels) due to decreased potassium excretion in the urine. Clients should monitor their potassium levels and avoid excessive intake of potassium supplements or foods, such as bananas, oranges, potatoes, and tomatoes.