Cephalexin 500 mg capsule for tooth infection

Diarrhea, nausea, vomiting, or upset stomach may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn't stop, abdominal or stomach pain/cramping, blood/mucus in your stool.

If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

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A tooth infection is a pocket of pus (abscess) caused by the proliferation of bacteria. Usually, an abscess appears in the pulp—the soft, living tissue inside a tooth.

A periapical abscess develops from an infection in the pulp that forms an abscess at the root of a tooth, while a periodontal abscess develops between the tooth and the surrounding gum tissue.

Symptoms of a tooth infection may include a severe toothache, sensitivity to heat and cold, swollen glands, swelling in the gums, foul-smelling breath, and pain while chewing. If the infection spreads to the surrounding bones, it may become life-threatening. 

Your dentist may prescribe antibiotics to clear up your tooth infection. Learn more about antibiotics for tooth infections, including why they are used and how fast they work.

Cephalexin 500 mg capsule for tooth infection
Cephalexin 500 mg capsule for tooth infection

Athima Tongloom / Moment / Getty Images

When Are Antibiotics Used for a Tooth Infection?

Tooth infections don’t always require antibiotics. In many cases, they may clear up on their own. Rinsing with warm saltwater or taking over-the-counter medicines, such as non-steroidal anti-inflammatory drugs (NSAIDs), may help to reduce tooth pain and swelling.

The American Dental Association (ADA) recommends that dentists avoid prescribing antibiotics for most tooth infections due to potential side effects. Dental treatments, such as drainage, deep cleaning, or a root canal (removing the infected pulp from the tooth), may sometimes be necessary.

However, your dentist may prescribe antibiotics if you are immunocompromised (have a weakened immune system) or if your tooth infection is spreading. Some of the signs that your tooth infection is getting worse may include:

  • Fever
  • Fatigue
  • Malaise (a general “ill feeling”)
  • Swelling in the jaw or neck
  • Intense pain or swelling that does not go away

If left untreated, a tooth infection may spread to the surrounding bones and tissues. This can lead to serious health complications, including:

  • Tooth loss
  • Blood infection
  • Pneumonia (lung infection)
  • Brain infection
  • Endocarditis (infection in the heart)

If you have a severe tooth infection, your dentist may prescribe a course of antibiotics to prevent it from spreading. Antibiotics may prevent tooth loss and other serious health complications.

When to See a Dentist

It’s important to seek dental treatment right away if you suspect you might have a tooth infection. Make an appointment with your dentist if you have a toothache that doesn’t go away, if your gums are red and inflamed, or if you notice a pimple-like bubble along your gum line.

Taking Antibiotics

Your dentist can diagnose you with a tooth infection with a thorough physical examination. Your healthcare provider may tap your teeth or ask you to bite down to assess your level of pain. They may also perform imaging tests, such as dental X-rays. 

If your tooth infection is severe or persistent, your dentist may prescribe antibiotics. The goals of taking antibiotics for a tooth infection are to prevent tooth loss and other serious health complications. 

According to the ADA, the first-line antibiotics for a tooth infection include: 

  • Oral amoxicillin
  • Oral penicillin V potassium

Amoxicillin and penicillin V potassium are both in a class of antibiotics known as penicillin-type drugs. They work to fight infections by killing bacteria or stopping its growth. Penicillin-type drugs won’t work to treat viral infections. 

If you are allergic to penicillin-type drugs, your dentist may prescribe one of the following antibiotics instead:

  • Oral azithromycin
  • Oral clindamycin
  • Oral cephalexin

Azithromycin, clindamycin, and cephalexin are all commonly used to treat bacterial infections.

Penicillin, Amoxicillin, and Cephalosporin Allergy: What to Know

Dosage

The current ADA recommendations for antibiotic dosage for tooth infections are as follows:

  • Oral amoxicillin: 500 milligrams (mg), three times per day
  • Oral penicillin V potassium: 500 milligrams, four times per day
  • Oral azithromycin: 500 milligrams on the first day, followed by 250 milligrams for four days
  • Oral clindamycin: 300 milligrams, four times per day
  • Oral cephalexin: 500 milligrams, four times per day

Duration

These are the current ADA recommendations for the duration of a course of antibiotics for a tooth infection:

  • Oral amoxicillin: Three to seven days
  • Oral penicillin V potassium: Three to seven days
  • Oral azithromycin: Five days
  • Oral clindamycin: Three to seven days
  • Oral cephalexin: Three to seven days

Some of your tooth infection symptoms should begin to clear up after two to three days. However, it’s important to take the full course of antibiotics as your dentist prescribes.

Taking Antibiotics

It’s important to take antibiotics exactly as prescribed, even if you start feeling better quickly. If you stop taking antibiotics too early, your infection may linger. You could also raise your risk of developing a bacterial infection that is resistant to antibiotics.

Common Antibiotics Used for a Tooth Infection

Penicillin-type drugs, such as amoxicillin and penicillin V potassium, are typically the first-line antibiotics that dentists prescribe to treat a tooth infection.

However, allergic reactions to penicillins are common. If you have a history of allergy symptoms (such as hives, swelling, or low blood pressure) after taking penicillin-type drugs, let your dentist know. They may prescribe a macrolide antibiotic, such as clindamycin, to clear up your infection. 

In some cases, your dentist may prescribe another type of antibiotic, such as:

  • Augmentin (amoxicillin with clavulanate)
  • Flagyl (metronidazole)

These drugs are typically prescribed if other antibiotics don’t work to treat your symptoms or if your tooth infection begins to spread.

Side Effects

Some of the most common side effects of antibiotics may include:

  • Nausea
  • Headache
  • Diarrhea
  • Yeast infection
  • Changes in taste 

Seek immediate medical help if you experience any serious side effects while taking antibiotics, such as:

  • Rash
  • Difficulty breathing
  • Wheezing
  • Hives
  • Peeling skin or blisters
  • Swelling in the face, eyes, or mouth 
  • Stomach cramps
  • Joint pain
  • Worsening signs of a tooth infection
  • Fever

Should I Go to a Hospital or a Dentist for My Dental Emergency?

Prevention

A tooth abscess may sometimes be caused by a cracked or chipped tooth, an injury, or failed dental work. However, in most cases, tooth infections are caused by tooth decay. 

The best way to prevent a tooth infection is to practice good oral hygiene. Here are some ways to protect your teeth from cavities and gum disease: 

  • Brush your teeth at least twice a day with fluoride toothpaste.
  • Floss or use interdental brushes regularly to remove hard-to-reach plaque from between your teeth.
  • Limit your sugar intake, especially between meals.
  • Visit your dentist regularly for cleanings and check-ups.

Summary

A tooth infection is a pocket of pus that develops inside a tooth's pulp due to the multiplication of bacteria. Tooth infections are usually caused by tooth decay, failed dental work, broken or chipped teeth, or injury.

Not all tooth infections require treatment with antibiotics. However, a dentist may sometimes prescribe antibiotics to save the tooth and prevent the infection from spreading. 

The most common antibiotics used to treat tooth infections are penicillin-type drugs (such as amoxicillin and penicillin V potassium). Clindamycin, azithromycin, and cephalexin are options for people who have a history of allergies to penicillin. If first-line drugs don't work, metronidazole may be prescribed.

Possible side effects of antibiotics for tooth infections may include nausea, diarrhea, yeast infection, changes in taste, and headache. More serious side effects, such as rash, hives, swelling, joint pain, and fever, require immediate medical attention.

A Word From Verywell

When tooth pain starts you may be tempted to delay calling a dentist. But a tooth infection can lead to serious health complications if left untreated. Talk to your dentist right away if you suspect that you have a tooth abscess.

Frequently Asked Questions

  • How long does it take for antibiotics to reduce swelling from tooth infection?

    In many cases, you’ll start feeling better about two to three days after you start taking antibiotics for a tooth infection. However, you should take the full round of prescribed antibiotics. Usually, your dentist will prescribe an antibiotic for three to seven days for a tooth infection.

  • How can I tell if the antibiotics are working for tooth infection?

    If your antibiotics are working, the symptoms of your tooth infection will begin to subside. Your fever, fatigue, pain, and/or swelling will decrease. If your symptoms persist or get worse, contact your dentist right away.

  • Are there any natural antibiotics for a tooth infection?

    The most popular natural treatment for a tooth infection is a warm saltwater rinse. Other home remedies for a tooth infection may include baking soda, garlic, hydrogen peroxide, aloe vera gel, herbal tea, or essential oils (such as oil of oregano or tea tree oil). However, if you have a tooth infection, you should still make an appointment with your dentist.

  • Where can I buy antibiotics for a tooth infection?

    The most common antibiotics for a tooth infection include amoxicillin, penicillin, azithromycin, clindamycin, cephalexin, and metronidazole. Antibiotics have to be prescribed by a healthcare provider, such as a dentist. You may be able to get a prescription more quickly via a telehealth visit.

    Can you use Cephalexin 500 mg for tooth infection?

    Yes, Cephalexin can be used to treat tooth abscess and gum infections. Cephalexin is in a group of drugs called cephalosporins antibiotics and is used to fight bacteria infections in the body. It works by interfering with the bacteria's cell wall formation, causing it to rupture, and killing the bacteria.

    How long does it take for cephalexin to work on tooth infection?

    Usually, within 2-3 days, you'll start feeling better and see an improvement in the infection.

    What is the strongest antibiotic for a tooth infection?

    Amoxicillin is usually the first choice for tooth infection treatment. If your tooth infection is more serious, your dentist may prescribe a combination of amoxicillin and another drug called Clavulanate. This combination is stronger and more effective against tooth infections.

    What antibiotics kills tooth infection?

    Antibiotics of the penicillin class, such as penicillin and amoxicillin, are most commonly used to help treat tooth infections. An antibiotic called metronidazole may be given for some types of bacterial infections. It's sometimes prescribed with penicillin in order to cover a larger variety of bacterial species.