A nurse is reviewing the laboratory data on a client who has a new prescription for heparin for treatment of a pulmonary embolism. Which of the following data should the nurse report 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.

Choice A reason: Reducing intake of potassium-rich foods is not necessary for clients taking hydrochlorothiazide, as this medication can cause hypokalemia (low potassium levels) due to increased potassium excretion in the urine. Clients may need to increase their intake of potassium-rich foods or take potassium supplements to prevent hypokalemia.

Choice B reason: Avoiding grapefruit juice is not necessary for clients taking hydrochlorothiazide, as this medication does not interact with grapefruit juice. Grapefruit juice can affect the metabolism of some other medications, such as statins, calcium channel blockers, and cyclosporine, by inhibiting the enzyme CYP3A4 in the liver.

Choice C reason: Taking this medication before bedtime is not advisable for clients taking hydrochlorothiazide, as this medication can cause increased urination and nocturia (nighttime urination). Clients should take this medication in the morning or at least 6 hours before bedtime to avoid disrupting their sleep.

Choice D reason: Monitoring for leg cramps is an important instruction for clients taking hydrochlorothiazide, as this medication can cause muscle cramps due to electrolyte imbalances, such as hypokalemia, hyponatremia (low sodium levels), or hypomagnesemia (low magnesium levels). Clients should report any signs of muscle cramps, weakness, or fatigue to their provider.