A nurse is assessing a client who reports feeling dizzy while getting out of bed. The nurse suspects orthostatic hypotension related to a medication the client is taking Which of the following medications should the nurse identify as likely causing this adverse effect?

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.

The client statement that indicates an understanding of the teaching is: "The medication can cause drowsiness."

Promethazine is an antihistamine medication commonly used to treat various conditions, such as allergies, motion sickness, and nausea. One of the most common side effects of promethazine is drowsiness or sedation. It has a significant sedative effect, and it is often used to induce sleep or manage insomnia in some cases.

Let's go through the other options:

A. "This medication can cause diarrhea": Diarrhea is not a common side effect of promethazine. While promethazine can cause certain gastrointestinal side effects like constipation or upset stomach, diarrhea is not typically associated with its use.

B. "The medication can cause increased salivation": Increased salivation is not a common side effect of promethazine. While some antihistamines can cause dry mouth, which is the opposite of increased salivation, promethazine does not usually cause excessive salivation.

C. "This medication can cause pupil constriction": Pupil constriction (miosis) is a potential side effect of some medications, but it is not commonly associated with promethazine. Promethazine is more likely to cause pupil dilation (mydriasis) rather than constriction.