A nurse is preparing to administer digoxin 0.25 mg PO to a client. The amount available is digoxin 0.125 mg tablets. How many tablets should the nurse administer to the client?

(Round to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

A. Increase the risk for bleeding: Herbal supplements like green tea, ginkgo, feverfew, garlic, and ginger can potentiate the effects of warfarin by enhancing its anticoagulant properties. This increases the risk of bleeding, as warfarin itself is a blood thinner designed to prevent clot formation. These herbs can further inhibit platelet aggregation or enhance anticoagulation, leading to a higher risk of bleeding complications.

B. Cause severe headache: While some herbal supplements can cause headaches as a side effect, this is not the primary concern when combined with warfarin. The interaction between these herbs and warfarin does not commonly result in severe headaches. The primary issue is the increased risk of bleeding.

C. Decrease the effects of the warfarin (Coumadin): These particular herbal supplements do not generally decrease the effects of warfarin. In fact, they are more likely to increase its anticoagulant effects. Some other substances might interfere with warfarin's efficacy, but the herbs listed are known to enhance its bleeding risk.

D. Cause severe hypotension: Severe hypotension is not a common result of combining these herbal supplements with warfarin. The primary interaction is related to the blood-thinning effects, not to blood pressure regulation. Herbal supplements that might affect blood pressure are not typically those that interact significantly with warfarin in this manner.

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.