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Drugs reference index «Penicillin VK»

Penicillin VK

Penicillin VK

Brand names: Penicillin V Potassium, Penicillin VK, Veetids

Why is Penicillin VK prescribed?

  • Penicillin V potassium is used to treat infections, including:Dental infection, infections in the heart, middle ear infections, rheumatic fever, scarlet fever, skin infections, upper and lower respiratory tract infections

Penicillin V works against only certain types of bacteria—it is ineffective against fungi, viruses, and parasites.

Most important fact about Penicillin VK

If you are allergic to either penicillin or cephalosporin antibiotics in any form, consult your doctor before taking penicillin V. There is a possibility that you are allergic to both types of medication; and if a reaction occurs, it could be extremely severe. If you take the drug and feel signs of a reaction, seek medical attention immediately.

How should you take Penicillin VK?

Penicillin V may be taken on a full or empty stomach, though it is better absorbed when the stomach is empty. Be sure to take it for the full time of treatment.

Doses of the oral solution of penicillin V should be measured with a calibrated measuring spoon. Shake the solution well before using.

  • If you miss a dose...Take it as soon as you remember. If it is almost time for the next dose, and you take 2 doses a day, take the one you missed and the next dose 5 to 6 hours later. If you take 3 or more doses a day, take the one you missed and the next dose 2 to 4 hours later, or double the next dose. Then go back to your regular schedule.
  • Storage instructions...Store in a tightly closed container. The reconstituted oral solution must be refrigerated; discard any unused solution after 14 days.

Tablets and powder for oral solution may be stored at room temperature.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Penicillin VK.

  • Side effects may include:Anemia, black, hairy tongue, diarrhea, fever, hives, nausea, skin eruptions, stomach upset or pain, swelling in throat, vomiting

Why should Penicillin VK not be prescribed?

You should not be using penicillin V if you have had an allergic reaction to penicillin or cephalosporin antibiotics.

Special warnings about Penicillin VK

If any allergic reactions occur, stop taking penicillin V and contact your doctor immediately.

If new infections (called superinfections) occur, consult your doctor.

If you have ever had allergic reactions such as rashes, hives, or hay fever, consult with your doctor before taking penicillin V.

Before taking penicillin V, tell your doctor if you have ever had asthma, colitis (inflammatory bowel disease), diabetes, or kidney or liver disease.

For infections such as strep throat, it is important to take penicillin V for the entire amount of time your doctor has prescribed. Even if you feel better, you need to continue taking Penicillin VK. If you stop taking Penicillin VK before your treatment time is complete, your infection may recur.

Possible food and drug interactions when taking Penicillin VK

If penicillin V is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining penicillin V with the following:

ChloramphenicolOral contraceptivesTetracyclines

Special information if you are pregnant or breastfeeding

The effects of penicillin V in pregnancy have not been adequately studied. If you are pregnant or planning to become pregnant, inform your doctor immediately. Penicillin V should be used during pregnancy only if your doctor determines that the potential benefit justifies the potential risk to the fetus. Since penicillin V appears in breast milk, you should consult with your doctor if you plan to breastfeed your baby. If Penicillin VK is essential to your health, your doctor may advise you to discontinue breastfeeding until your treatment is finished.

Recommended dosage for Penicillin VK


Continue taking penicillin V for the full time of treatment, even if you begin to feel better after a few days. Failure to take a full course of therapy may prevent complete elimination of the infection. It is best to take the doses at evenly spaced times, around the clock.

For mild to moderately severe strep infections of the upper respiratory tract and skin, and scarlet fever

The usual dosage is 125 to 250 milligrams every 6 to 8 hours for 10 days.

For mild to moderately severe pneumococcal infections of the respiratory tract, including middle ear infections

The usual dosage is 250 milligrams to 500 milligrams every 6 hours until you have been without a fever for at least 2 days.

For mild staph infections of skin

The usual dosage is 250 milligrams to 500 milligrams every 6 to 8 hours.

For mild to moderately severe gum infections known as Vincent's gingivitis

The usual dosage is 250 milligrams to 500 milligrams every 6 to 8 hours.

To prevent recurring rheumatic fever and/or chorea (infective disorder of the nervous system)

The usual dosage is 125 milligrams to 250 milligrams 2 times a day on a continuing basis.

Prevention of bacterial endocarditis (inflammation of the heart membrane) in people with heart disease who are undergoing dental or surgical procedures

For oral therapy, the usual dose is 2 grams of penicillin V taken one-half to 1 hour before the procedure, then 1 gram 6 hours later.


Any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

  • Symptoms of penicillin V overdose may include:Diarrhea, nausea, vomiting