A client with renal calculi is experiencing hematuria and reports severe flank pain.
Which intervention should the nurse implement first?

Choice A rationale:

The client's statement, "I should avoid foods that are high in vitamin K," indicates an understanding of the medication. Warfarin is an anticoagulant medication that works by inhibiting vitamin K-dependent clotting factors. Consistent intake of vitamin K-containing foods helps maintain a stable INR (International Normalized Ratio) and warfarin's effectiveness. Clients on warfarin should be educated about avoiding drastic changes in their vitamin K intake.

Choice B rationale:

Taking warfarin with food or on an empty stomach doesn't significantly impact its efficacy. Therefore, this statement is not indicative of the client's understanding of the medication.

Choice C rationale:

The statement "I should report any unusual bleeding or bruising to my provider" is important but doesn't specifically reflect an understanding of warfarin. It's a general caution for anyone taking anticoagulants.

Choice D rationale:

While it's important to avoid excessive use of medications like aspirin that can increase the risk of bleeding, this statement doesn't directly demonstrate an understanding of warfarin itself.

Choice A rationale:

The combination of trimethoprim and sulfamethoxazole has a synergistic effect, which means that the two drugs work together to inhibit bacterial growth more effectively than either drug alone. This combination is commonly used to treat urinary tract infections (UTIs) caused by susceptible bacteria.

Choice B rationale:

The combination of trimethoprim and sulfamethoxazole does not have an additive effect that reduces the dosage and frequency of administration of each drug. Instead, it is prescribed as a fixed combination with specific dosages of each drug.

Choice C rationale:

The combination of trimethoprim and sulfamethoxazole does not have an antagonistic effect that prevents the development of resistance to either drug. In fact, the combination is chosen because it covers a broader spectrum of bacteria and reduces the likelihood of resistance development.

Choice D rationale:

The combination of trimethoprim and sulfamethoxazole does not have a selective effect that targets only the bacteria causing the UTI and spares the normal flora. It affects a wide range of bacteria, including both pathogenic and normal flora.