Cefdinir vs Amoxicillin: Which Antibiotic Is Right for Your Infection?

When your doctor prescribes an antibiotic, you might hear cefdinir, a third-generation cephalosporin antibiotic used for respiratory, skin, and ear infections or amoxicillin, a penicillin-class antibiotic commonly used for sinus, throat, and urinary tract infections. Both fight bacteria, but they’re not interchangeable. One may work better for your specific infection, and the other could cause fewer side effects—or worse, trigger an allergic reaction if you’re sensitive to penicillin.

Amoxicillin is often the first choice because it’s cheap, well-studied, and effective for common bugs like strep throat or ear infections in kids. But if you’ve had a bad reaction to penicillin, or if your infection doesn’t clear up after a few days, your doctor might switch you to cefdinir, a broader-spectrum antibiotic that covers more types of resistant bacteria. Cefdinir is also used when amoxicillin fails, especially for stubborn sinus or lung infections. It’s not a penicillin, so it’s safer for people with penicillin allergies—unless you’re allergic to cephalosporins, which happens in about 1 in 10 cases.

Side effects differ too. Amoxicillin can cause diarrhea, nausea, or rash, especially in kids. Cefdinir might cause similar stomach issues, but it’s less likely to trigger yeast infections. Both can mess with your gut bacteria, but cefdinir stays active longer in your body, so you take it fewer times a day. Cost-wise, amoxicillin is usually cheaper, especially as a generic. But if you need something stronger or more targeted, cefdinir might be worth the extra price.

You won’t find one antibiotic that works for every infection. The choice depends on what’s causing your illness, your medical history, and whether you’ve taken antibiotics before. If you’ve used amoxicillin before and it didn’t help, cefdinir could be the next step. If you’ve had a rash with penicillin, cefdinir is likely your only safe option. Your doctor doesn’t just pick a drug—they pick the right tool for the job.

Below, you’ll find real-world comparisons, patient experiences, and clinical insights that show exactly when each antibiotic shines—and when it falls short. No fluff. Just what you need to understand why your prescription was chosen, and what to watch for next.