What is the best treatment approach for a 63-year-old male with type 2 diabetes (T2D), a single kidney, splenomegaly, cholelithiasis, hepatic steatosis, well-controlled hyperlipidemia and hypertension, but with impaired renal function (eGFR of 33), presenting with a mild upper respiratory tract infection and rhinorrhea?

Treatment of Mild Upper Respiratory Infection in a Patient with Advanced CKD

For this patient with eGFR 33 and a mild cold, acetaminophen (paracetamol) at standard doses is the safest medication choice, while NSAIDs must be strictly avoided due to high risk of acute kidney injury in advanced CKD. 1

Natural/Conservative Measures First

• Supportive care including adequate hydration, rest, and saline nasal rinses can effectively manage mild upper respiratory symptoms without medication risk 1
• Monitor fluid intake carefully given single kidney status and CKD stage 3b (eGFR 33), avoiding both dehydration and fluid overload 1
• Humidified air and steam inhalation may provide symptomatic relief for nasal congestion without systemic effects 1

Safest Pharmacological Option

• Acetaminophen (paracetamol) 500-650 mg every 6 hours as needed is the medication of choice for symptomatic relief 1
• Maximum daily dose should not exceed 3000 mg given hepatic steatosis, though standard dosing (up to 4000 mg/day) is generally safe in CKD 1
• No dose adjustment is required for acetaminophen in CKD, unlike many other medications 1

Critical Medications to Avoid

• NSAIDs (ibuprofen, naproxen, aspirin at analgesic doses) are absolutely contraindicated as they can precipitate acute kidney injury, particularly dangerous with eGFR 33 and single kidney 1
• Decongestants containing pseudoephedrine or phenylephrine should be avoided or used with extreme caution as they can elevate blood pressure, though your BP is currently controlled 1
• Combination cold medications often contain NSAIDs or multiple active ingredients—read labels carefully 1

Important Monitoring Considerations

• A temporary decline in eGFR during acute illness is common and expected; recheck renal function if symptoms persist beyond 7-10 days or worsen 1
• Ensure adequate but not excessive fluid intake—dehydration can worsen kidney function acutely 1
• Continue all current medications for diabetes, hypertension, and cholesterol unless specifically contraindicated during acute illness 1

Medication Management During Illness

• If you are taking metformin, continue it as your eGFR of 33 is above the discontinuation threshold of 30 mL/min/1.73 m², though monitor closely for any signs of worsening kidney function 1
• If on SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin), these can be continued but ensure adequate hydration to prevent volume depletion 1, 2
• ACE inhibitors or ARBs should generally be continued unless you develop severe dehydration or vomiting 1

When to Seek Medical Attention

• Fever above 38.5°C (101.3°F) persisting beyond 3 days 1
• Worsening symptoms after 7 days or development of productive cough with colored sputum 1
• Signs of dehydration: decreased urine output, dizziness, confusion 1
• Any signs suggesting bacterial superinfection requiring antibiotics (which would need renal dose adjustment) 1