When your doctor prescribes an antibiotic, you might not realize that cefadroxil, a first-generation cephalosporin antibiotic used to treat bacterial infections like strep throat and skin infections and amoxicillin, a penicillin-type antibiotic commonly used for ear infections, pneumonia, and urinary tract infections work in very different ways—even though they both fight bacteria. Both are oral antibiotics, often prescribed for similar infections, but they belong to separate drug families, which changes how your body responds to them and what side effects you might face.
One big difference is allergy risk. If you’re allergic to penicillin, amoxicillin is off-limits—it could trigger a serious reaction. But cefadroxil, a cephalosporin that’s structurally different from penicillin, might still be safe for many people with penicillin allergies, though not all. Your doctor will check your history carefully. Also, cefadroxil tends to be more stable against certain bacterial enzymes that break down penicillin, making it slightly more effective against some resistant strains. On the flip side, amoxicillin covers a broader range of common bacteria, especially those causing respiratory and ear infections, and it’s often the first choice for kids because it’s available in tasty liquid forms.
Side effects are similar—both can cause stomach upset, diarrhea, or nausea—but amoxicillin is more likely to cause a rash, especially in people with mononucleosis. Cefadroxil is usually taken once or twice a day, while amoxicillin often needs to be taken three times daily, which can make adherence harder. Cost-wise, both are cheap generics, but availability varies by pharmacy. If you’ve tried amoxicillin before and it didn’t work—or you had a bad reaction—cefadroxil could be the next step. But if you’re treating a typical strep throat or sinus infection, amoxicillin is still the go-to for most doctors.
Looking at the posts here, you’ll find clear comparisons like Ceclor CD vs amoxicillin and Cipro vs alternative antibiotics—all part of the same pattern: people want to know which antibiotic actually works for their situation. These aren’t just academic questions. Choosing the wrong one can mean a longer illness, unnecessary side effects, or even antibiotic resistance down the line. Below, you’ll see real-world breakdowns of how these drugs stack up against each other, what to watch for, and when to ask your doctor about switching. No fluff. Just what you need to understand your prescription.
