A 59-year-old Japanese man with atrial brillation presented to his physician complaining of red urine. The man had been receiving a standard dose of warfarin, which is an anticoagulant drug biotransformed by CYP2C9 isozyme. Which of the following was the most likely cause of the patient's disorder?

Correct Answer: C

Rationale: The most likely cause of the patient's disorder is genetic polymorphism of CYP2C9. This enzyme is responsible for metabolizing warfarin, and genetic variations in CYP2C9 can lead to altered metabolism of the drug, resulting in either increased or decreased anticoagulant effects. In this case, the red urine could be a sign of increased bleeding due to decreased metabolism of warfarin by the CYP2C9 enzyme, which is often seen in individuals with genetic polymorphisms affecting this enzyme.

Correct Answer: A

Rationale: Step 1: IV administration bypasses the need for patient compliance with oral medications. Step 2: Patients do not need to remember to take medications at specific times. Step 3: Improved patient compliance is not an advantage of IV administration. Step 4: Commercial availability, increased onset of action, and increased bioavailability are benefits. Step 5: Therefore, the correct answer is A: Improved patient compliance is not an advantage of IV administration. Summary: IV administration offers benefits like quick onset of action, high bioavailability, and availability of products, but it does not improve patient compliance since it does not require patients to remember to take medications orally.

Correct Answer: A

Rationale: The correct answer is A: Golgi apparatus. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and other substances for secretion or for use within the cell. It stores hormones and other substances before they are secreted or transported to other parts of the cell. Endoplasmic reticulum (B) is involved in protein synthesis, not storage. Mitochondria (C) are the powerhouse of the cell, generating energy. Lysosomes (D) contain enzymes for digesting waste materials, not for storage. Therefore, the Golgi apparatus is the correct choice for storing hormones and other substances.

Correct Answer: A

Rationale: The correct answer is A: Toxicity. Elevated serum creatinine level indicates impaired kidney function, leading to decreased drug clearance. This increases the risk of drug accumulation and toxicity in the body. Increased absorption (B) is not directly related to elevated creatinine levels. Delayed gastric emptying (C) affects drug absorption in the stomach, not clearance. Idiosyncratic effects (D) are unpredictable reactions unrelated to creatinine levels. Therefore, toxicity is the greatest risk due to impaired drug clearance in older adults with elevated serum creatinine levels.

Correct Answer: A

Rationale: The correct answer is A. For a 6-feet tall client weighing 280 pounds, the dose will be higher due to increased body weight requiring higher medication levels for therapeutic effect. Body weight influences drug distribution and metabolism. Option B is incorrect as higher weight typically requires higher dosage. Option C is incorrect as weight affects drug dosage. Option D is unrelated to the question about dosage based on weight and height.