What is "cefalexin"

alt. A particular oral cephalosporin antibiotic. n. A particular oral cephalosporin antibiotic.

Cefalexin, also spelled cephalexin, is an antibiotic that can treat a number of bacterial infections. It kills gram-positive and some gram-negative bacteria by disrupting the growth of the bacterial cell wall. Cefalexin is a beta-lactam antibiotic within the class of first-generation cephalosporins. It works similarly to other agents within this class, including intravenous cefazolin, but can be taken by mouth.

Cefalexin can treat certain bacterial infections, including those of the middle ear, bone and joint, skin, and urinary tract. It may also be used for certain types of pneumonia, strep throat, and to prevent bacterial endocarditis. Cefalexin is not effective against infections caused by methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus, or Pseudomonas. Like other antibiotics, cefalexin cannot treat viral infections, such as the flu, common cold or acute bronchitis. Cefalexin can be used in those who have mild or moderate allergies to penicillin. However, it is not recommended in those with severe penicillin allergies.

Common side effects include upset stomach and diarrhea. An allergic reaction and infection with Clostridium difficile, a type of diarrhea, is also possible. To date, no evidence of harm to the baby has been found when used during pregnancy or breast feeding. It can be used in children and those over 65 years of age. Those with kidney problems may require a decrease in dose.

In 2012, cefalexin was one of the top 100 most prescribed medications in the United States. In Canada, it was the 5th most common antibiotic used in 2013. In Australia, it is one of the top 15 most prescribed medications. Cefalexin was developed in 1967 and first marketed in 1969 and 1970 by a number of companies, including Glaxo Wellcome and Eli Lilly and Company under the names Keflex and Ceporex, among others. Generic drug versions are available under several other trade names and are inexpensive. Cefalexin is on the World Health Organization's List of Essential Medicines, the most important medications needed in a health system.