Cefadroxil Side Effects: What You Need to Know Before Taking It

When you’re prescribed cefadroxil, a first-generation oral antibiotic used to treat bacterial infections like strep throat, urinary tract infections, and skin infections. Also known as Cefadroxil monohydrate, it works by stopping bacteria from building cell walls—making it effective against many common infections. But like all antibiotics, it doesn’t just target the bad bugs; it can also upset your body’s balance. That’s why knowing the possible cefadroxil side effects matters more than just taking the pill.

Most people tolerate cefadroxil fine, but about 1 in 10 report mild issues like stomach upset, nausea, or diarrhea. These aren’t rare—they’re expected. More serious reactions, like severe diarrhea from C. diff bacteria, happen less often but can be dangerous if ignored. Allergic reactions, though uncommon, can show up as rash, swelling, or trouble breathing. If you’ve had reactions to penicillin or other cephalosporins, you’re at higher risk. Your body’s response to cefadroxil isn’t random—it’s tied to your history, your gut health, and even what else you’re taking. Drug interactions aren’t always obvious; mixing it with probenecid can raise its levels in your blood, and taking it with blood thinners might increase bleeding risk. It’s not just about the drug—it’s about how it fits into your whole health picture.

Some side effects are easy to miss. Fatigue, dizziness, or a metallic taste? These show up in patient reports but rarely make it into official leaflets. If you’re on cefadroxil for more than a week, watch for signs of yeast overgrowth—oral thrush or vaginal itching—because antibiotics wipe out friendly bacteria that keep fungi in check. Kidney function matters too; if you have kidney disease, your dose needs adjusting. This isn’t just a pill you swallow and forget. It’s a tool that interacts with your biology in real ways.

Below, you’ll find real patient experiences and expert breakdowns of how cefadroxil compares to other antibiotics like ampicillin and cefprozil. You’ll see what side effects show up most often, how to tell if it’s just a normal reaction or something serious, and what alternatives might work better for your situation. This isn’t theoretical—it’s what people actually deal with when they take this drug.