Cephalexin Side Effects

by on July 11, 2012


Cephalexin is an antibiotic used to treat infections caused by bacteria. The most common side effects of this medication are diarrhea, joint pain, stomach pain, tiredness, indigestion, headache, and dizziness. These side effects are generally not considered serious however, if they persist or become bothersome contact your doctor to discuss alternative solutions.

Common Cephalexin Side Effects

The most common Cephalexin side effects include the following:

  • Diarrhea
  • Joint pain
  • Stomach pain
  • Tiredness
  • Indigestion
  • Headache
  • Dizziness

Side effects that are less common include the following:

  • Mild nausea
  • Vaginal itching or discharge
  • Vomiting

The side effects listed above usually do not require medical attention as they will commonly diminish when your body adjusts to the medication. Your doctor may also be able to advise you of ways to reduce or prevent these common side effects from occurring. However, if any persist or become bothersome you should notify your doctor to discuss alternative solutions.

Serious Cephalexin Side Effects

An allergic reaction can occur while taking cephalexin. If you experience any of the following symptoms indicating an allergic reaction, get emergency medical help right away.

  • Hives
  • Difficulty breathing
  • Swelling of the lips, face, throat, or tongue

Many other side effects can occur while taking Keflex that are not indicative of an allergic reaction but are still very serious. If you experience any of the following side effects contact your doctor immediately.

  • Seizures
  • Jaundice
  • Dark urine
  • Confusion
  • Hallucinations
  • Agitation
  • Easy bruising or bleeding
  • Watery or bloody diarrhea
  • Decreased or no urination
  • Severe tiredness
  • Occurrence of fever, sore throat, headache, and severe rash with blistering and peeling skin.

Other Medical Conditions

Some medical conditions may require special tests or dosage adjustments to endure that you can safely take cephalexin. Talk to your doctor before taking this medication if you have any of the following conditions; kidney disease, malnourishment, diabetes, liver disease, or a stomach or intestine disorder. It is important to talk to your doctor if you are pregnant or may become pregnant; this medication has been placed in category B by the FDA, which means it is likely to be safe for an unborn child. You should also talk to your doctor if you are breastfeeding as this drug may pass through breast milk and the potential effects on a newborn are unknown.

Antibiotic Risks

Diarrhea is a common side effect of antibiotics. If you have diarrhea that has blood in it or is watery, you should contact your doctor as soon as possible and do not use any medications to stop diarrhea unless you have been advised to by a doctor. It is important to take the entire prescribed amount of cephalexin even if symptoms diminish early in treatment; stopping this medication early could allow bacteria to continue growing and result in the infection returning.

Cephalosporin Antibiotics

You should not use cephalexin if you have ever had an allergic reaction to it or to other cephalosporin antibiotics such as ceftazidime (Fortaz), cefuroxime (Ceftin), cefditoren (Spectracef), cefixime (Suprax), cefadroxil (Duricef), cefdinir (Omnicef), and cefaclor (Ceclor). Any of these medications could potentially cause an allergic reaction to occur in a person with a cephalexin allergy. If you experience any of the symptoms of an allergic response, get emergency medical help immediately.

Other Medications

It is important to tell your doctor about all over the counter, prescription, and herbal medications that you take prior to starting a new one. Tell your doctor if you take any of the following medications before taking cephalexin as they may cause a dangerous interaction to occur.

  • metformin (Fortamet, Glucophage, Riomet, Actoplus, Avandamet, Metaglip)
  • probenecid (Benemid)
  • ¬†Blood thinners such as warfarin (Coumadin)

Cephalexin is an antibiotic used to treat bacterial infections; it is not an appropriate medication for treating viral illnesses. Certain medical conditions may require special tests or a dosage adjustment to ensure that you can safely take this medication. If you experience any of the serious side effects associated with Keflex or if a common effect becomes bothersome, notify your doctor right away.