Cefaclor Dosage: What You Need to Know About Dosing, Side Effects, and Uses

When you’re prescribed Cefaclor, a second-generation cephalosporin antibiotic used to treat bacterial infections like ear infections, sinusitis, and urinary tract infections. Also known as Cefaclor monohydrate, it’s often chosen for its effectiveness against common bacteria and its availability in liquid form for kids. Getting the Cefaclor dosage right matters—too little won’t clear the infection, too much raises your risk of side effects.

Cefaclor works by stopping bacteria from building their cell walls, which kills them or stops them from spreading. It’s not for viral infections like colds or flu. Doctors usually prescribe it when other antibiotics like amoxicillin aren’t working or aren’t an option. For adults, the typical dose is 250 mg every 8 hours, or 500 mg every 12 hours, depending on the infection. For kids, it’s based on weight—usually 20 mg per kg of body weight per day, split into two or three doses. Always follow your doctor’s instructions. Never skip doses or stop early, even if you feel better. Stopping too soon can let the infection come back stronger.

Side effects are usually mild—stomach upset, diarrhea, or nausea—but some people get rashes or allergic reactions. If you’ve had a severe reaction to penicillin, you might react to Cefaclor too, since they’re both beta-lactam antibiotics. That’s why your doctor asks about your allergy history before prescribing it. For people with kidney problems, the dose might need to be lowered because Cefaclor is cleared by the kidneys. Older adults and young children need extra monitoring because their bodies process drugs differently.

There’s no one-size-fits-all Cefaclor dosage. A child with an ear infection gets a different amount than an adult with a skin infection. The form matters too—capsules, tablets, or oral suspension each have their own dosing rules. Liquid forms need shaking before use and must be measured with the right syringe or cup. Don’t guess the dose. If you miss a dose, take it as soon as you remember—unless it’s almost time for the next one. Never double up.

What you’ll find below are real, practical guides that dig into exactly how Cefaclor fits into treatment plans. You’ll see how it compares to other antibiotics like amoxicillin and cephalexin, what to watch for in kids, how kidney function changes dosing, and how to spot signs of trouble. These aren’t generic lists—they’re based on actual cases, patient experiences, and clinical guidance. Whether you’re a parent managing a child’s infection, an adult recovering from pneumonia, or just trying to understand why your doctor chose Cefaclor over something else, this collection gives you the clear, no-fluff details you need.