Keflex is the brand name for cephalexin, a common antibiotic doctors prescribe for skin infections, ear infections, throat infections, bronchitis, and some urinary tract infections. It kills bacteria by stopping their cell wall growth. That makes it useful for many common infections, but not for viruses like colds or the flu.
Adults often take 250–500 mg every 6–12 hours depending on the infection. For more serious infections, doctors may go up to 1 gram every 12 hours. Kids get doses based on weight — commonly 25–50 mg per kg per day split into several doses. Always follow the prescription. Finish the full course even if you feel better, because stopping early can let the infection come back stronger.
Take Keflex with or without food. If it upsets your stomach, try taking it with a meal. If you miss one dose, take it as soon as you remember unless it’s almost time for the next dose. Don’t double up to catch up.
The most common side effects are nausea, diarrhea, and mild stomach pain. A harmless but annoying effect can be yeast infections in some people. If you get widespread rash, swelling, trouble breathing, or throat tightness, treat it as an emergency — those can be signs of a serious allergic reaction.
If you have a penicillin allergy, tell your doctor. Most people who react to penicillin can still take cephalexin, but the risk of cross-reaction is higher if your penicillin reaction was severe. People with kidney problems may need lower doses because the drug leaves the body through the kidneys.
Watch for severe diarrhea or more than a few loose stools. Antibiotics can cause Clostridioides difficile (C. diff), which needs quick treatment. Also tell your provider about blood thinners or other medicines you take — some antibiotics can change how those drugs work.
Store Keflex at room temperature away from heat and moisture. Don’t use it past the expiration date and don’t share your antibiotic with others. Buying antibiotics online? Only use a licensed pharmacy and a valid prescription.
Questions to ask your prescriber: Is this antibiotic the best choice for my infection? How long should I take it? Do I need dose changes for kidney problems? What side effects should I report right away? These quick checks help you use Keflex safely and get better faster.
If you notice new or worrying symptoms while on Keflex, call your doctor. For routine cases, this antibiotic often works well and is inexpensive. Use it responsibly and follow simple safety tips to avoid complications.
Jan, 6 2025