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Cephalexin oral forms dosage: A detailed guide

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Cephalexin oral forms are prescribed to treat certain infections caused by bacteria in adults and some children. This medication is swallowed, usually two or four times a day, depending on your dosage.
Medically reviewed by Victor Nguyen, PharmD, MBA
Updated on

This article describes cephalexin oral forms’ dosages, strengths, and details on how to take the drug. You’ll also find information on cost savings and coupon options for cephalexin.

Cephalexin is a generic medication. It doesn’t come in a brand-name version.

If you want to know more about cephalexin oral forms, see this overview article. It covers details about the drug’s uses, side effects, ways to save on cost, and more.

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Forms and strengths of cephalexin

Cephalexin oral forms come as:

  • Tablets that you’ll swallow. These are available in strengths of:
    • 250 milligrams (mg)
    • 500 mg
  • Capsules that you’ll swallow. These are available in strengths of:
    • 250 mg
    • 500 mg
    • 750 mg
  • Liquid suspension that you’ll swallow. (This comes as a powder, and is mixed into a liquid mixture by a pharmacist.) It’s available in strengths of:
    • 125 mg per 5 milliliters (mL)
    • 250 mg per 5 mL

Cephalexin dosage

This article describes the recommended dosages for cephalexin oral forms. The drugmaker provides these dosages.

If your doctor prescribes this medication, they’ll determine the dosage that’s best for you. Do not change your dosage of cephalexin oral forms without your doctor’s recommendation.

Usual recommended dosages of cephalexin

Cephalexin is used to treat certain bacterial infections in adults and some children. Viral infections, such as the common cold, can’t be treated with cephalexin oral forms. Examples of infections doctors may prescribe cephalexin to treat include:

The information below describes dosages that are commonly prescribed.

Dosage for UTI, skin infection, and other infections

For certain bacterial infections in adults and children ages 15 years and older, cephalexin’s recommended dosages are:

  • 250 milligrams (mg) once every 6 hours for 7 to 14 days, or
  • 500 mg once every 12 hours for 7 to 14 days

For severe infections, doctors may increase the dosage to 4 grams (g), divided into two or four doses per day. (For information about dosages for younger children, see the section below.)

Pediatric dosages of cephalexin

Cephalexin oral forms are approved to treat certain bacterial infections in children older than 1 year of age. (For children ages 15 years and older, dosages are the same as for adults. See the section directly above for details.)

For children older than 1 year of age and younger than 15 years of age, doctors calculate cephalexin dosages using the child’s body weight. For reference, 1 kilogram (kg) equals 2.2 pounds (lb). Recommended dosages for this age group are described in the table below:

ConditionRecommended dosages, which are usually given for 7 to 14 days
ear infection75 mg to 100 mg per kg of body weight per day, given in divided doses, every 6 hours
other infections*25 mg to 50 mg per kg of body weight per day, given in divided doses, usually every 6 or 12 hours
severe infections50 mg to 100 mg per kg of body weight per day, given in divided doses, usually every 6 or 12 hours

* Examples of other infections include respiratory tract infection, skin infection, UTI, and bone infection.

For example, a child weighing 30 kg (about 66 lb) with a respiratory tract infection may be prescribed a daily dosage of 750 mg to 1,500 mg. (This would be calculated as 25 mg to 50 mg of drug per kg of body weight.) It would be given as divided doses throughout the day as instructed by a doctor. 

Dosage adjustments for cephalexin

Your doctor will prescribe a dosage of cephalexin oral forms based on several factors, including:

  • the specific condition being treated and how severe it is
  • your age
  • other health conditions you may have

Specifically, if you have kidney problems, your doctor may decrease your dosage of cephalexin oral forms. If your kidneys are not working well, talk with your doctor before starting cephalexin treatment.

Missed dose of cephalexin

It’s important that you don’t miss a dose or stop taking cephalexin before you finish your treatment course. If you do so, your infection may get worse or not improve.

Talk with your doctor or pharmacist right away if you realize you forgot a dose of cephalexin. They may advise you to take the missed dose. Or they may advise you to skip it and take your next dose as scheduled.

For tips on how to plan your doses of cephalexin and avoid missing a dose, read this article. You could also try:

  • downloading a reminder app on your phone
  • setting an alarm
  • putting a note where you’ll see it, such as on your calendar, bathroom mirror, or bedside table

Frequently asked questions

Below are answers to some commonly asked questions about cephalexin oral forms and dosage.

Is cephalexin used in dogs? If so, what’s the dosage?

Veterinarians can prescribe Cephalexin to treat certain bacterial infections in dogs. The recommended dosage of cephalexin for dogs depends on the type of infection the drug is prescribed to treat. Your veterinarian will calculate the correct dosage.

Talk with your veterinarian about cephalexin and the dosage that’s right for your dog. You should only give your dog medications that are prescribed for them by a veterinarian.

Is there a recommended dosage of 500 mg four times per day for cephalexin?

Yes, it’s possible that a doctor may prescribe a dosage of 500 milligrams (mg) four times per day. To view usual cephalexin dosages, see the “Dosage of cephalexin” section above.

For severe infections, doctors may prescribe a dosage of cephalexin up to 4 grams (g), divided into two or four doses per day. For some tooth infections, dentists may prescribe a dosage of 500 mg four times per day.

Talk with your doctor about the dosage of cephalexin that’s right for you.

Does cephalexin have a recommended dosage calculator?

A cephalexin dosage calculator is not provided by the drugmaker.

Dosage recommendations for adults and children ages 15 years and older are provided. But some cephalexin dosages are calculated based on weight. This includes maximum dosages and dosages for children older than 1 year of age but younger than 15 years of age. See the “Dosage of cephalexin” section above for details.

Your doctor may use a calculator to determine weight-based dosages. Talk with your doctor to learn more about how cephalexin dosages are calculated.

Can cephalexin be prescribed for a tooth infection? If so, what’s the dosage?

Yes, dentists may prescribe cephalexin for tooth infections, such as abscesses and gum infections.

The American Dental Association recommends a cephalexin oral dosage of 500 mg four times per day in adults with a mild allergy to penicillin (as an alternative to penicillin-related drugs). This dose will likely be taken for 3 to 7 days to treat a tooth infection. But be sure to take the dosage your dentist or doctor prescribes.

If you’d like, ask your dentist for more information about medications used for tooth infections. Your dentist can recommend a treatment option that’s right for you.

Is cephalexin taken long term?

No, doctors don’t usually prescribe cephalexin as a long-term treatment. It’s usually recommended as a short-term treatment.

Most people will likely take cephalexin oral forms for 7 to 14 days, depending on the condition being treated. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take cephalexin short term.

How cephalexin is taken

Cephalexin oral forms are swallowed, with or without food. You’ll likely take the medication one to four times a day, depending on your dosage.

Your doctor may advise that you take cephalexin around the same time each day. This can help the drug work more effectively because it keeps a consistent amount of the drug in your body.

If it’s hard for you to swallow capsules or tablets, view this article. It provides suggestions on how to swallow medications that come in pill form.

Also, be sure to talk with your doctor or pharmacist if you’re having difficulty taking your medication. They can offer recommendations about taking it.

Cephalexin coupon

Visit this page to access Optum Perks coupons and get price estimates for cephalexin when you use the coupons. These coupons can provide significant savings on your prescription costs. 

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

You can also refer to this in-depth article for details about the cost of cephalexin treatment.

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Overdose of cephalexin

It’s important that you do not take more cephalexin oral forms than your doctor prescribes. Doing so can lead to harmful effects.

Symptoms of cephalexin overdose

Symptoms of an overdose can include:

What to do if you take too much cephalexin

If you think you’ve taken too much cephalexin, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have severe symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

What to ask your doctor

This article describes the usual recommended dosages for cephalexin oral forms. If your doctor prescribes this medication, they’ll determine the dosage that’s best for you.

Do not change your dosage of cephalexin oral forms without your doctor’s recommendation. You should take cephalexin exactly as your doctor prescribes it.

Let your doctor know if you have concerns or questions about your treatment plan.

Here’s a list of some possible questions you may want to ask your doctor:

  • Will you change my dosage of cephalexin if I have side effects from the drug?
  • How will you change my dosage if I have kidney problems, and will I need to be monitored during my treatment?
  • If I’m older than 65 years of age, will you adjust my dosage of cephalexin?

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

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