Keflex Alternatives: What Works When You Need a Substitute

If your doctor prescribed Keflex (cephalexin) but you can’t take it—maybe you’re allergic, it didn’t clear the infection, or your pharmacy is out of stock—you’ll need another antibiotic that hits the same bugs. Below you’ll find the most common Keflex alternatives, when they work best, and what to watch for.

Oral antibiotics similar to Keflex

Amoxicillin is often the go‑to for skin, ear, and throat infections. It’s a penicillin, so it works well against many of the same bacteria that Keflex does. If you’re not allergic to penicillin, it’s a cheap, easy option. Watch for stomach upset and, rarely, a rash.

Dicloxacillin belongs to the same penicillin family but is better against staph infections that resist regular penicillins. It’s useful for cellulitis or infected cuts. Same allergy warnings apply, and it can cause mild diarrhea.

Clindamycin steps in when you can’t use penicillins or cephalosporins. It covers a lot of skin and bone infections, especially if the bug is anaerobic (likes low oxygen). The downside is a higher chance of diarrhea and, in some cases, a serious gut infection called C. diff.

Azithromycin is a macrolide antibiotic that’s handy for respiratory infections and some skin bugs. It’s taken once a day, which many people like. It can cause mild nausea and may interact with other meds, so check with your pharmacist.

Trimethoprim‑sulfamethoxazole (Bactrim) works well for urinary tract infections and some skin infections. It hits a different set of bacteria, so it’s a solid backup when resistance to cephalosporins is a concern. Watch for rash, sun sensitivity, and avoid it if you have kidney issues.

When to pick a different class

If you have a confirmed penicillin allergy, skip amoxicillin, dicloxacillin, and clindamycin unless your doctor says it’s safe. In that case, azithromycin or Bactrim are safer bets.

For infections that involve bone or deep tissue, doctors sometimes add an IV drug like vancomycin or a fluoroquinolone. Those aren’t “alternatives” you’ll buy at the pharmacy, but knowing they exist helps you understand why a doctor might switch you to a stronger regimen.

Always finish the full course, even if you feel better early. Stopping too soon lets surviving bacteria become resistant, which makes future infections harder to treat.

Before you start any new antibiotic, talk to your healthcare provider about your medical history, current meds, and any past reactions. A quick chat can prevent a nasty side effect and get you on the right drug faster.

In short, there’s a handful of reliable Keflex alternatives you can discuss with your doctor. Whether you need a penicillin, a macrolide, or a sulfa drug, knowing the options makes the conversation smoother and gets you back to feeling good sooner.