Keflex (cephalexin) is a cephalosporin antibiotic. It works by fighting bacteria in your body. Keflex is used to treat many different types of infections caused by bacteria. Keflex may also be used for purposes not listed in this medication guide.
More common side effects
Less common side effects
blistering, peeling, or red skin rash
bruising or bleeding
halos around lights
yellowing of the skin or eyes
Rare side effects
chest pain or discomfort
Keflex can cause serious side effects. Stop taking Keflex and call your doctor at once if you have:
severe stomach pain, diarrhea that is watery or bloody;
kidney problems–little or no urination, blood in your urine, swelling, rapid weight gain;
signs of a severe allergic reaction: hives, fever, swollen glands, joint pain, general ill feeling, unusual bruising or bleeding, severe fatigue, nausea, vomiting, rapid breathing, skin rash, itching.
Keflex can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
Do not give Keflex to a child without medical advice.
The recommended dose for most types of bacterial infections is 250 mg every 6 hours, or 500 mg every 12 hours. Keflex may be taken with or without food.
To treat a bladder infection, the recommended adult dose is 3 grams (mg) in a single dose. Keflex should be taken at evenly spaced intervals.
How does Keflex work?
Keflex belongs to a class of drugs called cephalosporin antibiotics. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions. Keflex works by killing bacteria that cause infections.