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Even though cephalexin is not considered addictive, there may be health risks to suddenly stopping this medication. Stopping cephalexin too soon or skipping doses may also fail to effectively treat the infection and potentially cause some bacteria to become resistant to the drug. 

How Long Do Cephalexin Withdrawal Symptoms Last?

The amount of time it takes for a person to go through withdrawal depends on the substance in question. With cephalexin, it’s highly unlikely for a person to experience withdrawal symptoms since it’s not habit-forming; therefore, it’s not known how long withdrawal symptoms last nor how long they take to show up. 

Certain serious effects of this drug–including diarrhea, stomach cramps, and fever–may persist for up to two months after taking the medication.

Withdrawal Symptoms

Possible symptoms of cephalexin withdrawal include agitation, anxiety, insomnia, muscle aches, fatigue, and headaches. But, because cephalexin is not habit-forming, it is considered unlikely for a person to experience these effects. 

However, cephalexin is known to cause general side effects in some people. These side effects include:

  • Diarrhea
  • Nausea
  • Vomiting
  • Rectal or genital itching
  • Heartburn
  • Stomach pain
  • Fatigue
  • Dizziness
  • Agitation
  • Confusion
  • Headaches
  • Joint pain

It is also possible to overdose on cephalexin. Signs and symptoms of cephalexin overdose include:

  • stomach pain, 
  • diarrhea, 
  • nausea, 
  • vomiting, and 
  • pink, red, or brown urine.


Always take cephalexin as prescribed by a medical doctor. It should only be taken if a bacterial infection is strongly suspected or proven. If you notice any serious side effects–including difficulty breathing or swallowing, hives or rash, swelling of the throat or face, watery or bloody stools, and hallucinations–call a doctor or visit an emergency room right away. 

Treatment Options

The best way to avoid any possible withdrawal symptoms from cephalexin is to take the medication exactly as prescribed by a medical provider. This includes continuing to take the entire prescription of cephalexin until all the pills are gone, even if signs and symptoms of the underlying infection completely go away. Failing to do so can mean that the infection is not entirely treated and that the infection-causing bacteria not only survive, but become antibiotic resistant. This resistance means it can be even harder to treat the infection.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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