SOLVED: 3. An 81-year-old woman with a history of atrial fibrillation on digoxin therapy complains of nausea and yellow discoloration of her vision (symptoms of digoxin toxicity). She is 155 cm tall, and weighs 44.5 kg (BMI 18.5). Her electrolytes, creatinine, gamma-glutamyl transferase and bilirubin are within normal limits. Her serum digoxin level is 1.7ng / mL (therapeutic range 0.8-1.8), and her serum albumin level is 27 g / dL (normal 3.5-5.0). The most likely explanation for this woman's s