A nurse is caring for a client who has a magnesium level of 3.2 mEq/L. Which of the following medications should the nurse expect to administer?

A. Hemoglobin level: The hemoglobin level measures the amount of hemoglobin, the oxygen-carrying protein in red blood cells, in the blood. Warfarin is not directly responsible for increasing or decreasing the hemoglobin level. While warfarin can lead to bleeding complications in some cases, it does not specifically target the hemoglobin level, so it is not a direct indicator of the medication's effectiveness.

B. Platelet count: The platelet count measures the number of platelets in the blood, which are essential for blood clotting. Warfarin does not directly affect platelet production or count. It works by inhibiting the production of certain clotting factors, not by affecting platelets. Monitoring the platelet count is important, but it is not an indicator of warfarin's effectiveness in preventing excessive clotting.

C. Prothrombin time (PT) or activated partial thromboplastin time (aPTT): Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are coagulation tests used to assess different types of anticoagulant medications, such as heparin. Warfarin's effect is measured using the International Normalized Ratio (INR). PT and aPTT are not specific to warfarin therapy and are not used to monitor its effectiveness. The INR is the appropriate laboratory test for assessing the efficacy of warfarin therapy.

D. International Normalized Ratio (INR): This is the correct answer. The International Normalized Ratio (INR) is the laboratory test used to monitor the effectiveness of warfarin therapy. The INR measures the time it takes for the blood to clot and reflects the anticoagulant effect of warfarin. A therapeutic INR within the target range (e.g., INR = 2.0 to 3.0 for most indications) indicates that warfarin has been effective in preventing excessive clotting and reducing the risk of complications associated with blood clots.

Oxybutynin is an anticholinergic medication commonly used to treat urinary incontinence. One of the adverse effects of anticholinergic medications is the potential for bradycardia, which refers to a slower than normal heart rate. Anticholinergic medications can inhibit the effects of acetylcholine, a neurotransmitter responsible for regulating various bodily functions, including heart rate. Therefore, it is important to assess the client for signs of bradycardia after an unintended higher dose of oxybutynin.

Increased salivation (A) is not an expected adverse effect of oxybutynin. In fact, anticholinergic medications like oxybutynin often have the opposite effect, causing dry mouth and reduced salivation.

Hyperthermia (B) is not a typical adverse effect of oxybutynin. It is more commonly associated with other conditions or medications.

Urinary incontinence (C) is the condition that oxybutynin is intended to treat. It is not an adverse effect but rather the therapeutic effect of the medication.