A nurse is caring for a client who has developed agranulocytosis as a result of taking propylthiouracil to treat hyperthyroidism. The nurse should understand that this client is at increased risk for which of the following conditions?

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.

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.