Cephalexin Cephalexin is an antibiotic used to treat UTIs. It's also commonly used to treat bacterial infections in patients who are allergic to Penicillin. The oral tablet or capsule is taken at the same time each day, with or without food. It is not effective for treating colds, flu, or other viral infections. Read more about urinary tract infection.
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Using this information

This overview does not include all the information available about this medication. It doesn't guarantee your personal safety while using it. And it doesn't guarantee that the medication will be effective or suitable for you. You should not trust it over advice from a medical professional.

Contact your health provider for accurate information about this medication and your treatment. You can update your UTI treatment online by requesting a provider callback via your patient dashboard.

Medication name
Key points about Cephalexin Medication

This medication treats a broad range of bacterial infections—including urinary tract infections (UTIs).

Cephalexin is an Cephalosporin antibiotic UTI medicine. It works by impeding bacterial growth. It does not treat viral infections like the common cold or flu. The unnecessary or excessive use of any antibiotic can reduce Cephalexin’s effectiveness.

Administration of Cephalexin
  • Take this UTI prescription medication orally as instructed by your medical professional. It’s usually taken every 6 to 12 hours. It can be taken with or without food.
  • To achieve the best results, stick to a consistent schedule. Try to take your UTI medication at the same time(s) each day.
  • Continue taking this UTI treatment until you complete the prescribed amount. (Finish it even if symptoms go away in just a few days.) Bacteria may continue to grow if you stop taking this UTI antibiotic too soon. This can lead to a relapse infection.
  • If symptoms persist or worsen, request a callback from your healthcare provider via your patient dashboard.
Possible side effects
  • Possible side effects include diarrhea, nausea, vomiting or stomach discomfort.
  • If side effects persist or intensify, contact your provider. You can request a callback from your medical provider to discuss Cephalexin via your online patient dashboard.
  • A medical professional prescribed this UTI medication because its benefits outweigh the potential side effects. Most people who use this medicine do not experience serious adverse reactions.
  • Prolonged or repeated use of this medication may lead to oral thrush or a new yeast infection. If you notice white patches in your mouth, changes in vaginal discharge or other new symptoms? Request a callback from your medical provider.
  • In rare instances, Cephalexin may trigger an intestinal condition caused by an overgrowth of C. difficile bacteria. This can occur during treatment or several weeks to months after stopping treatment. C. diff symptoms include persistent diarrhea, abdominal or stomach pain/cramping and blood or mucus in your stool. If you experience any of these, request a callback from your healthcare provider. Avoid anti-diarrhea medicines and opioids—they may exacerbate symptoms.
  • Severe allergic reactions to this drug are uncommon. Seek immediate medical assistance if you notice any severe symptoms. These include a rash, itching, swelling (particularly of the face, tongue, or throat), severe dizziness or difficulty breathing.
  • This is not an exhaustive list of adverse reactions associated with Cephalexin. If you notice side effects not listed above, request a medical provider callback through your patient dashboard.
Important precautions to consider
  • Before starting Cephalexin UTI antibiotic treatment, inform your provider about any known allergies. These include allergies to Cephalexin, penicillins, other Cephalosporins (e.g., Cefpodoxime) and other substances. This UTI medication might contain inactive ingredients that could trigger an allergic reaction or other complications.
  • Give your provider a comprehensive medical history before starting this medication. This is vital if your medical history includes kidney disease or stomach/intestinal conditions like colitis.
  • Cephalexin may make live bacterial vaccines (like the typhoid vaccine) less effective. Let your provider know you're taking Cephalexin before any immunizations or vaccinations.
  • Before undergoing surgery, make sure your medical providers know about all the products you are using. These include prescription drugs, nonprescription drugs and herbal products.
  • Only take Cephalexin during pregnancy if absolutely necessary. Discuss the risks and benefits with your medical provider and OB-GYN.
  • This drug may be present in breast milk. So consult your OB-GYN before taking this medication if breastfeeding.
Drug interactions
  • Drug interactions can alter the efficacy of your medication or increase the risk of severe side effects. This document does not cover all possible drug interactions.
  • Maintain a comprehensive list of all products you use and share it with your healthcare provider. These include prescription drugs, nonprescription drugs and herbal products.
  • Only start, stop or change this UTI antibiotic medication dosage with direct approval from your healthcare provider.
  • The antiarrhythmic drug Dofetilide may interact with Cephalexin. This can affect the result of cupric sulfate-type urine glucose tests. Before such tests, tell laboratory personnel and other medical providers that you're taking Cephalexin.
What to do in the event of an overdose

Cephalexin overdose symptoms include persistent vomiting, bloody urine and seizures.

Call 911 immediately if you experience overdose symptoms like loss of consciousness or difficulty breathing. For less severe symptoms, contact your local poison control center at 1-800-222-1222.

Other points to consider

Your provider has prescribed this UTI medication for your specific, current condition. Do not share this medication with others. Don't use it for a following infection unless instructed by a healthcare provider.

Stay up-to-date with periodic laboratory and/or medical tests. Such tests include complete blood counts, kidney and liver function assessments and urine cultures. These will track your progress and help you identify side effects. Request a callback from your healthcare provider for further details.

Did you miss a dose? Here's what to do.

Forget to take a dose? Take it as soon as you remember. If nearing the time for your next scheduled dose, don’t take a dose to catch up. Instead, skip the missed dose and continue with your regular dosing schedule.

Proper storage of this medication
  • Store Cephalexin UTI pills at room temperature, away from direct light and moisture.
  • Refrain from storing it in the bathroom. (It’s steamy there.)
  • Cephalexin brands may differ in how they should be stored. Consult the packaging of your Cephalexin product or ask your pharmacist about the most effective way to store it.
  • Make sure children and pets can't reach or get into any medication.
  • Keep the container tightly closed. Discard any unused medication after 14 days.
  • If you no longer need the medication or it expired, contact your pharmacist or local waste disposal company. They'll tell you how to best dispose of it. Only flush medications down the toilet or drain if instructed to do so.
Generic Name
Drug Class
Cephalosporin antibiotic

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