Acute Otitis Media
Oral cephalexin is used for the treatment of acute otitis media (AOM) caused by susceptible Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, staphylococci, or streptococci.
When anti-infective therapy is indicated for the treatment of AOM, the American Academy of Pediatrics (AAP) recommends high-dose amoxicillin or amoxicillin and clavulanate potassium as the drugs of first choice for initial treatment. These experts recommend certain cephalosporins (cefdinir, cefpodoxime, cefuroxime, ceftriaxone) as alternatives for initial treatment in penicillin-allergic patients who do not have a history of severe and/or recent penicillin-allergic reactions.
For additional information regarding treatment of AOM, including information on diagnosis and management strategies, anti-infectives for initial treatment, duration of initial treatment, and anti-infectives after initial treatment failure, see .
Pharyngitis and Tonsillitis
Oral cephalexin is used for the treatment of pharyngitis and tonsillitis caused by S. pyogenes (group A β-hemolytic streptococci). Although cephalexin generally is effective in eradicating S. pyogenes from the nasopharynx, efficacy of the drug in prevention of subsequent rheumatic fever has not been established to date.
Selection of an anti-infective for the treatment of S. pyogenes pharyngitis and tonsillitis should be based on the drug's spectrum of activity, bacteriologic and clinical efficacy, potential adverse effects, ease of administration, patient compliance, and cost. No regimen has been found to date that effectively eradicates group A β-hemolytic streptococci in 100% of patients.
Because the drugs have a narrow spectrum of activity, are inexpensive, and generally are effective with a low frequency of adverse effects, the AAP, Infectious Diseases Society of America (IDSA), American Heart Association (AHA), and others recommend a penicillin regimen (i.e., 10 days of oral penicillin V or oral amoxicillin or single dose of IM penicillin G benzathine) as the treatment of choice for S. pyogenes pharyngitis and tonsillitis and prevention of initial attacks (primary prevention) of rheumatic fever. Other anti-infectives (e.g., oral cephalosporins, oral macrolides, oral clindamycin) are recommended as alternatives in penicillin-allergic individuals.
If an oral cephalosporin is used for the treatment of S. pyogenes pharyngitis and tonsillitis, a 10-day regimen of a first generation cephalosporin (cefadroxil, cephalexin) is preferred instead of other cephalosporins with broader spectrums of activity (e.g., cefaclor, cefdinir, cefixime, cefpodoxime, cefuroxime).
Bone and Joint Infections
Oral cephalexin is used for the treatment of bone and joint infections caused by susceptible staphylococci or Proteus mirabilis.
Respiratory Tract Infections
Oral cephalexin is used for the treatment of mild to moderate respiratory tract infections caused by susceptible S. pneumoniae.
Skin and Skin Structure Infections
Oral cephalexin is used for the treatment of mild to moderate skin and skin structure infections caused by susceptible staphylococci or streptococci.
Urinary Tract Infections
Oral cephalexin is used for the treatment of mild to moderate urinary tract infections, including acute prostatitis, caused by susceptible Escherichia coli, Klebsiella pneumoniae, or P. mirabilis.
Prevention of Bacterial Endocarditis
Oral cephalexin is used as an alternative for prevention of α-hemolytic (viridans group) streptococcal endocarditis in penicillin-allergic individuals undergoing certain dental or upper respiratory tract procedures who have underlying cardiac conditions that put them at highest risk of adverse outcomes from endocarditis. Cephalexin should not be used for such prophylaxis in those with a history of immediate-type hypersensitivity to penicillins (e.g., urticaria, angioedema, anaphylaxis).
For information on which cardiac conditions are associated with highest risk of endocarditis and which procedures require prophylaxis, see . When selecting anti-infectives for prophylaxis of bacterial endocarditis, the current recommendations published by AHA should be consulted.