What Is Cefalexin?

Part of the cephalosporin group of drugs, cefalexin can be used to treat a variety of bacterial infections. It kills bacteria by interfering with the structure of the cell wall. Many parts of the body can be treated with cefalexin if an infection occurs, from the urinary tract to the skin. The drug comes in various forms, including liquids and tablets, but is generally taken by mouth.

Cefalexin is also known by the alternative spelling cephalexin. This drug is an antibiotic, and works on certain species of bacteria, but is useless for infections which involve viruses or fungi. Examples of the common microbial species that the drug can kill include Staphylococcus aureus, Escherichia coli and various streptococcal species.

These bacteria need cell walls to protect and support the inside of the cell. Cefalexin, like the cephalosporin group of antibiotics in general, attacks the cell wall. It sticks to the wall and prevents the cell from maintaining the correct structure, thus causing the cell's destruction. The substance itself is formed through artificial means but from naturally occurring materials, and so falls into the semi-synthetic group of antibiotics.

Bacteria can attack and infect various parts of the body, and cefalexin is appropriate for use for a variety of infections. These infections will only clear up if the bacterial species causing them are vulnerable to cefalexin, however. Skin infections may necessitate treatment with the drug, as may ear or throat infections. Diseases of the reproductive tract or of the urinary tract, may also clear up with this type of antibiotic. Serious infections that attack the bone, or the lungs, can also be cured using cefalexin treatment.

Typically, a patient takes the drug twice a day or more for up to 10 days. The drug is offered in tablet, capsule or liquid form, but generally, it must be swallowed. Most often, when side effects occur, they involve vomiting or diarrhea, although a skin rash may develop. Allergic reactions are a potentially serious side effect, and these can cause the patient to swell up so much that breathing is inhibited, which can be life-threatening.

People who are allergic to any of the antibiotics in the cephalosporin group may not be able to take cefalexin. Patients with kidney or live disease, or those on other medications, may also be unsuitable. Pregnant or breastfeeding women also require a doctor's advice before using the drug, in case of risk to the baby.