Why they’re risky: Some antivirals can crystallize in kidney tubules or cause direct cellular toxicity, especially at high doses or with dehydration.
✅ Safer approach:
- Take exactly as prescribed—never double up on doses
- Drink plenty of water while on these medications
- Ensure your provider monitors kidney function with blood tests during treatment
- Ask about newer formulations (like tenofovir alafenamide) that may be gentler on kidneys
7. Metformin (In Specific Situations)
Why it’s nuanced: Metformin is a first-line diabetes medication that’s generally safe and even kidney-protective long-term. However, in people with severely reduced kidney function (eGFR <30), it can rarely contribute to lactic acidosis.
✅ Safer approach:
- Get regular eGFR tests if you take metformin
- Never stop diabetes medication without consulting your provider
- Stay hydrated, especially during illness or before procedures involving contrast dye
- Know that guidelines have expanded—many people with mild-moderate kidney disease can safely continue metformin