A nurse is caring for a client who has been taking warfarin and has a prothrombin time of 30 seconds and an INR of 7. Which of the following medications should the nurse anticipate the provider to prescribe?

A. "The anticoagulant effect of a single dose of aspirin can last for as long as a month." This statement is incorrect. While aspirin has antiplatelet effects that inhibit blood clot formation, its duration of action is not as long as a month. Aspirin irreversibly inhibits the enzyme cyclooxygenase (COX), thereby inhibiting platelet aggregation. However, the effects on platelet function are not permanent, and platelets turnover within a few days, thus the anticoagulant effect of a single dose of aspirin typically lasts for a shorter duration.

B. "The anticoagulant effect of a single dose of aspirin can last for as long as a day." Aspirin's primary effect is on platelets, not directly on overall blood clotting. It inhibits the COX enzyme, reducing the production of thromboxane A2, a chemical that promotes platelet aggregation. The initial inhibition of platelet function is strongest within the first 24 hours after taking aspirin. However, the affected platelets remain dysfunctional for their entire lifespan (around 7-10 days).

C. "The anticoagulant effect of a single dose of aspirin can last for as long as a week." This statement is correct. Aspirin's effect on platelets is due to its irreversible inhibition of the COX enzyme. Platelets have a lifespan of about 7-10 days. Once a platelet is affected by aspirin, it cannot regain its function. As your body continuously produces new platelets, the overall antiplatelet effect gradually diminishes over time.

D. "The anticoagulant effect of a single dose of aspirin can last for as long as 12 hours."

Rationale: This statement is partially correct. The antiplatelet effect of aspirin does not typically last as short as 12 hours. While the peak inhibition of platelet function occurs within hours after administration, the duration of action is longer due to the irreversible inhibition of COX-1. However, stating that it lasts exactly 12 hours may not be entirely accurate for all individuals, as the duration of action can vary depending on factors such as individual metabolism and dose.

A. Alteplase (Activase): Alteplase is a thrombolytic agent used to dissolve blood clots. Concurrent use with clopidogrel, an antiplatelet medication, can increase the risk of bleeding due to additive effects on clotting. Therefore, it's important to consult the doctor before using these medications together.

B. Diltiazem: Diltiazem is a calcium channel blocker used to treat hypertension and certain heart rhythm disorders. Diltiazem will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Therefore, it's advisable to consult the doctor before using these medications together.

C. Ibuprofen: Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain and inflammation. Like other NSAIDs, it can increase the risk of bleeding when taken with clopidogrel. Therefore, it's important to consult the doctor before using these medications together.

D. Aspirin: Aspirin is another antiplatelet medication commonly used to prevent heart attacks and strokes. Combining clopidogrel with aspirin can increase the risk of bleeding without significantly improving outcomes in most cases. However, in some situations, such as after certain cardiac procedures, dual antiplatelet therapy (clopidogrel plus aspirin) may be prescribed under close medical supervision. Therefore, it's crucial to consult the doctor before using these medications together.

E. Coumadin (warfarin): Coumadin is an anticoagulant medication used to prevent blood clots. Concurrent use with clopidogrel can increase the risk of bleeding. Therefore, it's essential to consult the doctor before using these medications together.