Review Question - QID 108800

A 66-year-old male presents to a primary care clinic with a blood glucose level of 169 mg/dL that was taken at a local pharmacy. He is a rural farmer and has not seen a doctor for decades. He wants to be in excellent shape prior to his trip to visit his daughter at college. His past medical history and family history are unknown and he does not take any medications. His diet is primarily composed of processed meats. He drinks alcohol socially and he does not smoke. His temperature is 99.5°F (37.5°C), pulse is 100/min, blood pressure is 169/90 mmHg, respirations are 18/min, and oxygen saturation is 97% on room air. The patient is started on metformin, lisinopril, and a guided exercise program. Lab results are below:

Serum:
Na+: 145 mEq/L
Cl-: 100 mEq/L
K+: 4.9 mEq/L
HCO3-: 24 mEq/L
BUN: 18 mg/dL
Glucose: 211 mg/dL
Creatinine: 1.0 mg/dL
Ca2+: 10.0 mg/dL

He returns from his trip, complaining of cough. He denies any other symptoms. His temperature is 99.5°F (37.5°C), pulse is 101/min, blood pressure is 160/85 mmHg, respirations are 18/min, and oxygen saturation is 98% on room air. Repeat lab results are below:

Serum:
Na+: 145 mEq/L
Cl-: 100 mEq/L
K+: 5.3 mEq/L
HCO3-: 24 mEq/L
BUN: 22 mg/dL
Glucose: 169 mg/dL
Creatinine: 1.2 mg/dL
Ca2+: 10.1 mg/dL

What is the most appropriate next step in management?