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. Minutes: This is too short a timeframe for warfarin's effect. It takes longer for the body's existing clotting factors to be depleted.

B. Days: This medication works by inhibiting the production of vitamin K-dependent clotting factors in the liver. As existing clotting factors are used up and new ones aren't produced as efficiently, it takes time for the anticoagulant effect to become significant.

C. Weeks: While the full effect might take some time (around 3-5 days), several weeks is an overestimation for most patients.

D. Hours: A few hours might show some initial effect, but it's not enough time for a substantial anticoagulant effect. It usually takes at least a day or two.

A. Diminished effect from warfarin: This is unlikely because displacement of warfarin from protein binding sites would increase its concentration in the bloodstream, potentially leading to increased anticoagulant effects and toxicity.

B. Diminished effect from paroxetine: This is also unlikely because displacement of paroxetine from protein binding sites would increase its concentration in the bloodstream, potentially leading to increased pharmacological effects and toxicity.

C. Increased effect, and toxicity from paroxetine: If paroxetine displaces warfarin from protein binding sites, it can increase the concentration of free warfarin in the bloodstream, leading to increased anticoagulant effects and potential toxicity.

D. Increased effect, and toxicity from warfarin: Correct. If warfarin is displaced from protein binding sites by paroxetine, it can increase the concentration of free warfarin in the bloodstream, leading to increased anticoagulant effects and potential toxicity.