A 65-year-old man presents to the internal medicine clinic with decreased exercise tolerance, lower extremity edema, and shortness of breath.
He has a history of diastolic dysfunction (ejection fraction of 60%) and hypertension; BP =
150/90 mm Hg, HR = 86 bpm.
Current medications include digoxin 125 mcg daily, furosemide 40 mg daily, enalapril 10 mg twice daily, aspirin 325 mg daily, and potassium 10 mEq twice daily. The digoxin concentration is 0.4 ng/mL.
After resolution of this exacerbation, which of the following should the pharmacotherapy specialist recommend to the internist regarding this patient's maintenance drug therapy?

A patient in an ICU has been receiving heparin 5,000 units subcutaneously three times daily for the last 7 days. Today the patient's platelet count has dropped by more than 50%, and the patient has developed a pulmonary embolism. The patient's heparin platelet factor 4 antibody test is positive.
What is the most appropriate treatment for this patient's pulmonary embolism?

A population study of gentamicin pharmacokinetics in 425 neonates reported the following correlation by least-squares linear regression between gestational age and gentamicin clearance:
r2 = 0.35, p = 0.0001. Which of the following is the most appropriate interpretation of these data?

Using a new assay, the following readings for Drug X concentration in a blood sample are obtained: 45 ng/mL, 43 ng/mL, 45 ng/mL, 44 ng/mL, 45 ng/mL, and 45 ng/mL. The true concentration of the drug was reported as 65 ng/mL using the gold-standard assay.
On the basis of these data, the new assay should be characterized in which of the following categories?

A 47-year-old patient with end-stage renal disease undergoing hemodialysis has an HCT of 23% and exhibits anginal symptoms. Upon further Workup, no evidence of occult bleeding is found.
In addition to antianginal therapy, which of the following is the most appropriate initial treatment for this patient's anemia?