A 53-year-old man with HIV and insulin-dependent diabetes mellitus was diagnosed with HIV more than 25 years ago and has high-level multi-resistant HIV. He is taking a complex salvage antiretroviral regimen of dolutegravir, darunavir (boosted with ritonavir), fostemsavir, and tenofovir DF-emtricitabine. Routine laboratory testing in the emergency room shows a creatinine of 2.4 mg/dL, potassium of 3.0 mEq/L, and a bicarbonate of 15 mmol/L. A urinalysis shows 3+ glucose, 2+ protein, and pH = 5.1.