Review Question - QID 109869

A 45-year-old man presents to the emergency department with difficulties swallowing food. He experiences pain when he attempts to swallow his medications or when he drinks water. He was diagnosed with HIV infection 5 years ago. He asserts that he has been taking his antiretroviral regimen, including emtricitabine, rilpivirine, and tenofovir. His temperature is 98°F (37°C), blood pressure is 100/60 mmHg, pulse is 90/min, respirations are 22/min, and oxygen saturation is 99% on room air. His physical exam is notable for a clear oropharynx, no lymphadenopathy, and a normal cardiac and pulmonary exam. No rashes are noted throughout his body. His laboratory results are displayed below:

Hemoglobin: 12 g/dL
Hematocrit: 37%
Leukocyte count: 8,000/mm^3 with normal differential
Platelet count: 160,000/mm^3

Serum:
Na+: 138 mEq/L
Cl-: 108 mEq/L
K+: 3.5 mEq/L
HCO3-: 26 mEq/L
BUN: 35 mg/dL
Glucose: 108 mg/dL
Creatinine: 1.1 mg/dL

CD4+ count: 90/mm^3
HIV viral load: 59,000 copies/mL

Which of the following is the most appropriate next step in management?