Cephalexin: What It Is, When to Use It & Key Facts

If you’ve been handed a pill labeled Cephalexin, you’re probably wondering what it does and whether it’s right for your infection. In plain terms, Cephalexin is a first‑generation cephalosporin antibiotic that targets a wide range of bacteria, especially those causing skin, ear, bone, and urinary tract infections.

How Cephalexin Works and Common Uses

The drug attacks the bacterial cell wall, stopping the microbes from growing and eventually killing them. Because it’s not as broad‑spectrum as some newer antibiotics, doctors often pick it for straightforward infections where resistance isn’t a big worry.

Typical reasons to prescribe Cephalexin include:

• Cellulitis or other skin infections
• Strep throat (when penicillin can’t be used)
• Simple urinary tract infections
• Bone infections like osteomyelitis
• Ear infections in kids

Dosage Tips, Side Effects, and Safer Alternatives

The usual adult dose is 250‑500 mg every 6‑8 hours, taken with food to reduce stomach upset. Kids get a weight‑based dose, so always follow the doctor’s exact instructions.

Most people tolerate Cephalexin well, but common side effects are mild: nausea, diarrhea, or a temporary rash. If you notice severe itching, swelling, or breathing trouble, stop the medication and seek help right away—those could be signs of an allergic reaction.

When allergies to penicillin or cephalosporins exist, doctors might swap in alternatives such as:

• Cefadroxil – another first‑generation cephalosporin with a similar safety profile
• Clindamycin – useful for anaerobic infections and when resistance is suspected
• Doxycycline – a broader option that covers atypical bugs but isn’t ideal for pregnant women or kids under eight

Before you start, tell your pharmacist about any other meds you’re on. Cephalexin can interact with blood thinners like warfarin, making clotting tests harder to interpret.

Overall, Cephalexin is a solid, affordable choice for many everyday infections. Keep the course of treatment as prescribed—stopping early can let bacteria bounce back and become resistant.

Got more questions about a specific dose or need help spotting a side effect? Our guide section on antibiotics breaks down each drug in plain English, so you can feel confident about what’s in your medicine cabinet.