Keflex is an antibiotic belonging to the category cephalosporin’s. The other name for Keflex is Cephalexin. It is an antibiotic similar in nature to Penicillin. Keflex has the primary function same as all other antibiotics. It alters the bacterial cell wall and restricts their growth.


Keflex is used to treat different bacterial infections such as the upper respiratory tract infections. These include tonsillitis, otitis media (infection of the middle ear), throat infections, infection of the voice box (laryngitis). Keflex is also effective against lower respiratory tract infections such as bronchitis and pneumonia. A medical practitioner may also prescribe it for urinary tract infections and dental infections.

Other than these infections, it works well against bone and joint infections as well.


Keflex comes in three forms. Capsules, tablets and suspension. The dosage depends on the type of infection and the age of the patient.

The average adult dosage ranges from 1-4 gm. per day.

The doses are divided into 500 mg per six or eight hours. 

For mild infections, the dose may be 250 mg per 6 hours or 500 mg per 12 hours.

The dosage is defined by the doctor according to the patient’s condition.

For children under 5 years of age, the advised dosage is 125 mg per eight hours.

For children over 5 years, 250 mg per eight hours is what doctors recommend.

The typical dosage for kids under the age 18 is 12.5mg-25 mg/ kg depending on the severity of infection. For severe infections, double doses are recommended.

Side Effects:

The common side effects of Keflex include:

  • nausea
  • diarrhea
  • stomach pain
  • dizziness
  • fatigue
  • Vaginal discharge and itching.

The uncommon side effects include:

  • diarrhea that leads to bloody stool 
  • bruising under the skin
  • a seizure,
  • dark urine
  • pale skin
  • Unusually cold hands and feet.

 These side effects need immediate attention from the doctor.


  • There’s a fair chance of having an allergic reaction to this medicine. It can cause blisters on the skin or rashes. Some people may experience abnormal swelling on the face, hands, feet or sex organs. In case of any such side effect, consult with your doctor immediately. 
  • The medicine can cause diarrhea that should never be counter cured by another drug. If the diarrhea worsens, go to your doctor without attempting self-medication.
  • While taking Keflex, make sure that you take the proper prescribed dosage.
  • Do not stop taking this medicine sooner than your doctor’s advice. Always take it with a marked cup/spoon to ensure correct quantity usage. A tablespoon does not quantify the drug correctly.
  • Do not take Keflex longer than prescribed.
  • In case you have skipped a dose, take it as soon as you recall but skip if the next dose is just a couple of hours away. Double dosing can increase the quantity of medicine in your body than the allowed limit at a time that can lead to severe repercussions. 
  • Patients with kidney dysfunction should be prescribed with this medicine by practicing extreme caution.