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Penicillin V (By mouth)

Penicillin V (pen-i-SIL-in V)

Treats or prevents infections caused by certain types of bacteria. This medicine is an antibiotic.

Brand Name(s):

Truxcillin VK

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had an allergic reaction to any type of penicillin.

How to Use This Medicine:

Liquid, Tablet

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
  • It is best to take this medicine on an empty stomach, 1 hour before or 2 hours after a meal.
  • Shake the oral liquid well just before each use. Measure the medicine with a marked measuring spoon or medicine cup.
  • Take all of the medicine in your prescription to clear up your infection, even if you feel better after the first few doses.
  • This medicine is not for long-term use.

If a dose is missed:

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine:

  • Store the tablets at room temperature, away from heat, moisture, and direct light.
  • Store the oral liquid in the refrigerator. Do not freeze.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed. Discard any unused portion of the oral liquid after 14 days.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are also using probenecid (Benemid®).
  • Birth control pills, implants, or shots may not work while you are using penicillin. To keep from getting pregnant, use another form of birth control such as condoms, a diaphragm, or a contraceptive foam or jelly.

Warnings While Using This Medicine:

  • Make sure your doctor knows if you are pregnant or breastfeeding, or if you have asthma, allergies, kidney disease, liver disease, or problems with absorbing food. Tell your doctor if you have ever had an allergic reaction to a cephalosporin antibiotic (such as cefaclor, cefadroxil, cephalexin, Ceftin®, or Keflex®).
  • This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Stop using this medicine and call your doctor right away if you have itching, hives, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.
  • Ask your doctor before you take any medicine to stop severe diarrhea.
  • Call your doctor if your symptoms do not improve or if they get worse.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering, peeling, red skin rash.
  • Coughing, difficulty in breathing or swallowing, or wheezing.
  • Fever, chills, sore throat, and body aches.
  • Swelling of the joints and lymph glands.
  • Watery or bloody diarrhea.

If you notice these less serious side effects, talk with your doctor:

  • Black, hairy tongue.
  • Mild diarrhea, nausea, vomiting, or upset stomach.
  • Vaginal itching or discharge.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088


Last Updated: 4/4/2014

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