Cefaclor Comparison: How It Stacks Up Against Other Antibiotics

When you're prescribed Cefaclor, a second-generation cephalosporin antibiotic used to treat bacterial infections like ear infections, bronchitis, and urinary tract infections. Also known as a beta-lactam antibiotic, it works by stopping bacteria from building cell walls, which kills them or stops them from spreading. Unlike first-gen options like cephalexin, Cefaclor has a broader reach—especially against some strains of H. influenzae and E. coli that older antibiotics struggle with.

But how does it compare to the more common amoxicillin, a penicillin-class antibiotic often used as a first-line treatment for ear and sinus infections? Many patients assume all antibiotics are the same, but that’s not true. Cefaclor is often chosen when amoxicillin fails—maybe because the infection is resistant, or the patient has a mild penicillin allergy. It’s also more stable in stomach acid than some other cephalosporins, so it’s absorbed better. Then there’s cefuroxime, another second-gen cephalosporin, often used in more serious respiratory infections. Cefuroxime has slightly better coverage against certain gram-negative bacteria, but Cefaclor is usually cheaper and taken less often per day. And unlike azithromycin, a macrolide that targets different bacteria and is used for atypical infections like walking pneumonia, Cefaclor doesn’t work on mycoplasma or chlamydia.

Side effects matter too. Cefaclor can cause diarrhea, nausea, or rash—just like other antibiotics—but it’s less likely to trigger severe allergic reactions than penicillin-based drugs. Still, if you’ve had anaphylaxis to penicillin, you should avoid Cefaclor unless tested by an allergist. It’s also not the first pick for kids under 12 with ear infections anymore—amoxicillin is still the go-to there. But for adults with recurring sinus or urinary infections that won’t clear with amoxicillin, Cefaclor is a solid backup.

Cost, dosing, and resistance patterns change fast. In some regions, Cefaclor is off-patent and dirt cheap. In others, newer antibiotics have pushed it to the sidelines. But it’s still in use—especially where access to advanced meds is limited. What you’ll find in the posts below are real, side-by-side comparisons: how Cefaclor stacks up against amoxicillin in ear infections, how it fares against cefuroxime in bronchitis, and when doctors actually reach for it instead of the usual suspects. No fluff. Just what works, what doesn’t, and why.