Penicillin V (By mouth)

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

Treats or prevents bacterial infections. This medicine is an antibiotic.

Brand Name(s):

When This Medicine Should Not Be Used:

How to Use This Medicine:

Liquid, Tablet, Capsule

• 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 oral liquid medicine with a marked measuring spoon, oral syringe, 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.
• Missed dose: 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.
• Tablets: Store at room temperature, away from heat, moisture, and direct light.
• Oral liquid: Store in the refrigerator. Do not freeze. Discard any medicine you have not used after 14 days.

Drugs and Foods to Avoid:

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

• Some medicines and foods can affect how penicillin works. Tell your doctor if you also use methotrexate or warfarin.
• 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.

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have asthma, allergies, kidney disease, liver disease, or digestion problems. Tell your doctor if you had an allergic reaction to a cephalosporin antibiotic.
• This medicine can cause diarrhea. Call your doctor if the diarrhea becomes severe, does not stop, or is bloody. Do not take any medicine to stop diarrhea until you have talked to your doctor. Diarrhea can occur 2 months or more after you stop taking this medicine.
• Call your doctor if your symptoms do not improve or if they get worse.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

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
• Severe diarrhea, fever, stomach cramps

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: 12/4/2023