Classes Anti-infective Agent
Diseases Infectious Disease


Cephalexin is a 1st generation cephalosporin antibiotic of the beta lactam class. It is available as capsule, tablets and suspension for oral administration. It kills susceptible bacteria by inhibiting cell wall synthesis.

Cephalexin is indicated for the following infections caused by susceptible organisms-

  • Respiratory tract infections
  • Otitis
  • Skin and skin structure infection
  • Bone infections
  • Urinary tract infection

Oral Cephalexin is usually taken in 250 mg every 6 hours, however it can also be taken in 500 mg every 12 hours. The treatment lasts between 7 and 14 days.

The side effects of cephalexin is usually mild. The most commonly seen side effects are-

  • Nausea
  • Vomiting
  • Abdominal pain
  • Hypersensitivity (Very rare)
  • Although very rare, Hypersensitivity reactions may occur in some patients.
  • Prolonged use of Cephalexin may cause the overgrowth of resistant organisms like Candida sp. and Clostridium difficile. 
  • Patient might experience Clostridium difficile associated diarrhea with prolonged use of cephalexin.
  • Taking alcohol while on treatment with cephalexin can cause disulfiram like reaction.
  • Patients with renal impairment may require dosage adjustment.


Cephalexin is contraindicated in patients who are hypersensitive to any beta lactam antibiotics.


Alcohol should not be taken while on treatment with cephalexin.

There is no contraindications of cephalexin in terms of health condition.