Cephalexin Uses

Cephalexin is used for the treatment of certain infections caused by bacteria, including respiratory tract, ear, skin and skin structure, bone, genital, and urinary tract infections.

Cephalexin is sometimes used in penicillin allergic patients with heart conditions for prophylaxis (prevention) before upper respiratory or dental procedures.

Note: Antibiotics are only effective against infections that are caused by bacteria. They do not work against viruses and cannot treat viral illnesses such as the common cold or flu.

There may be other uses of cephalexin—your doctor or health system pharmacists can give you further drug information.

Cephalexin Mechanism of Action

Cephalexin kills bacteria by preventing them from forming a protective bacterial cell wall. 

Cephalexin Doses

This antibiotic is available as cephalexin capsules (250 mg, 333 mg, 500 mg, and 750 mg), cephalexin tablets (250 mg and 500 mg), and cephalexin oral suspension (125 mg/5 mL and 250 mg/5 mL). 

The usual dose of cephalexin in people 15 years of age and older is 250 mg every 6 hours. It can also be taken as 500 mg every 12 hours. The maximum daily dose is 1,000 to 4,000 mg per day. Older adults and people with reduced kidney function may need to take lower doses.

In pediatric patients older than 1 year of age, the dose of cephalexin is based on the child’s body weight. For otitis media (middle ear infection), the dose is 75-100 mg/kg given in equally divided doses every 6 hours. For all other infections, the dose is 25-50 mg/kg, although doses of 50-100 mg/kg may be used to treat infections that are severe.