A nurse in a coronary care unit is admitting a client who has had CPR following a cardiac arrest. The client is receiving lidocaine IV at 2 mg/min. When the client asks the nurse why he is receiving that medication, the nurse should explain that it has which of the following actions?

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: Platelets 190,000/mm3 is within the normal range of 150,000 to 450,000/mm3. This result does not indicate a bleeding risk or a need to adjust the warfarin dose.

Choice B reason: Hct 44% is within the normal range of 37% to 47% for females and 42% to 52% for males. This result does not indicate anemia or polycythemia, which could affect the warfarin therapy.

Choice C reason: PT 45 seconds is above the normal range of 11 to 13.5 seconds. This result indicates that the blood is taking too long to clot, which increases the risk of bleeding. The nurse should notify the provider and expect a decrease in the warfarin dose.

Choice D reason: Hgb 16 g/dL is within the normal range of 12 to 16 g/dL for females and 14 to 18 g/dL for males. This result does not indicate anemia or polycythemia, which could affect the warfarin therapy.