Keflex or Cephalexin

Why is this drug prescribed?
Cephalexin is an antibiotic that eliminates the bacteria that cause different kinds of infections, including pneumonia and infections of the ear, urinary tract, skin and bone.

When should it be used?
Cephalexin is usually taken four times a day, every six hours, for seven to 10 days. If it is not possible to take the drug around the clock, take it at evenly spaced intervals between the time you wake up in the morning and the time you go to bed at night (for example, at 7 a.m., noon, 5 p.m., and 10 p.m.). Follow the instructions on your prescription label carefully, and ask us or your pharmacist to explain any part that you do not understand.

How should it be used?
Cephalexin comes in capsules, tablets, and liquid to be taken by mouth. Your prescription label tells you how much to take at each dose. It is best to take Cephalexin on an empty stomach; therefore, try to take it one hour before meals or at least two hours after meals. Tablets and capsules should be taken with a full glass of water. Liquid Cephalexin should be shaken well before each use to mix the medication evenly. Liquid doses should be measured with a specially marked dropper or measuring spoon, available from your pharmacist. Your prescription is probably not refillable. If you still have symptoms after you finish the Cephalexin, contact us.

What special instructions should I follow while using this drug?
Take all the medication prescribed, even after the infection appears to have gone away. Failure to do so could allow the infection to return.

What should I do if I forget to take a dose?
Take the missed dose as soon as you remember it. Take any remaining doses for that day at evenly spaced intervals.

What side effects can this drug cause? What can I do about them?

  • Skin rash, shortness of breath, itching, hives
    Stop taking the drug and Contact us immediately.
  • Nausea and/or vomiting
    Take Cephalexin with crackers or a light snack.
If you continue to have stomach upsets, contact us. If you experience diarrhea that is severe or continues for more than two days, or unusual bleeding, bruising, painful mouth, or throat sores, Contact us.

What other precautions should I follow while using this drug?
Before taking this medication, tell us if you are allergic to penicillins or cephalosporins (e.g., Cefaclor, Cefadroxil, and Cephradine); if you have asthma, hay fever, allergies, or kidney disease; or if you are nursing a baby. If you are taking medication for gout, such as Probenecid, tell us before taking Cephalexin. If we tell you to stop taking Cephalexin, throw away any unused medication. Cephalexin may lose its effectiveness over time and should not be saved to treat another infection. Cephalexin may cause false positive results in tests for sugar in the urine. Diabetics should use TesTape rather than Clinitest tablets to test for sugar while taking this drug.