eGFR: What It Means for Your Kidney Health and How Medications Affect It

When your doctor talks about eGFR, estimated glomerular filtration rate, a measure of how well your kidneys filter waste from your blood. Also known as estimated glomerular filtration rate, it’s one of the most important numbers for tracking kidney health over time. If your eGFR drops below 60 for three months or more, it’s a sign of chronic kidney disease—even if you feel fine. Most people don’t notice kidney problems until they’re advanced, which is why this simple blood test matters more than you think.

Your kidneys don’t just make urine—they regulate blood pressure, balance electrolytes, and remove drugs from your system. That’s why creatinine, a waste product from muscle breakdown that’s used to calculate eGFR levels are so critical. High creatinine means your kidneys aren’t clearing it out well. But creatinine alone doesn’t tell the full story. Age, muscle mass, sex, and race all affect eGFR. A 70-year-old with normal creatinine might have an eGFR of 55 and still be healthy, while a 30-year-old with the same number likely has kidney damage.

Many medications you take daily can quietly lower your eGFR. NSAIDs, common painkillers like ibuprofen and naproxen that reduce blood flow to the kidneys are a top offender. Long-term use, even at over-the-counter doses, can cause lasting harm. So can some antibiotics, blood pressure drugs like ACE inhibitors (especially if you’re dehydrated), and even certain antivirals. If you’re on multiple meds, especially with diabetes or high blood pressure, your eGFR should be checked at least once a year. A sudden drop after starting a new drug? That’s not normal—it’s a red flag.

It’s not just about the number. What matters is the trend. A slow decline over years might mean you need lifestyle changes. A sharp drop after a hospital stay or new medication could mean you need to stop something fast. People with diabetes, heart failure, or a history of kidney stones are at higher risk. And if you’re over 60, your kidneys naturally filter slower—but that doesn’t mean you should ignore a falling eGFR.

You’ll find posts here that dig into how common drugs like aspirin, diuretics, and proton pump inhibitors affect kidney function. Others explain why some people get kidney damage from antibiotics while others don’t. There’s even a guide on how dehydration from diuretics can crash your eGFR overnight. These aren’t theoretical warnings—they’re real stories from patients who didn’t know their meds were hurting their kidneys until it was too late.

Knowing your eGFR isn’t about fear. It’s about control. It’s about asking your doctor, "Is this drug safe for my kidneys?" before you fill the prescription. It’s about catching problems early when they’re still fixable. Below, you’ll find clear, no-fluff guides on the medications that threaten kidney health—and what to do instead.