Penicillin V potassium is used to treat certain infections caused by bacteria such as pneumonia and other respiratory tract infections, scarlet fever, and ear, skin, gum, mouth, and throat infections. It also is used to prevent rheumatic fever (a serious condition that may develop after a strep throat or scarlet fever infection and may cause swelling of the heart valves and other symptoms) from coming back. Penicillin V potassium is in a class of medications called penicillins. It works by killing bacteria.
Antibiotics such as penicillin V potassium will not work for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
HOW should this medicine be used?
Penicillin V potassium comes as a tablet and as an oral solution (liquid) to take by mouth. For the treatment of infections, it is usually taken every 6 hours (four times a day) or every 8 hours (three times a day). For the prevention of rheumatic fever, it is usually taken twice a day. The length of your treatment depends on the type of infection that you have. Take penicillin V potassium at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take penicillin V potassium exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Shake the oral solution well before each use to mix the medication evenly.
Take penicillin V potassium until you finish the prescription, even if you feel better. Do not stop taking penicillin V potassium without talking to your doctor. If you stop taking penicillin V potassium too soon or if you skip doses, your infection may not be completely treated and the bacteria may become resistant to antibiotics.
Are there OTHER USES for this medicine?
Penicillin V potassium is also sometimes used to treat certain anthrax infections of the skin. It also sometimes used with other medications to treat diphtheria (a serious sickness that causes problems breathing and other symptoms, uncommon in developed countries).
Penicillin V potassium is also sometimes used to prevent a heart valve infection in certain patients who have a heart condition and require a dental or upper respiratory tract (nose, mouth, throat, voice box) procedure.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What SPECIAL PRECAUTIONS should I follow?
Before taking penicillin V potassium,
tell your doctor and pharmacist if you are allergic to penicillin V potassium, other penicillin antibiotics, cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, Kefzol), cefepime (Maxipime), cefixime (Suprax), cefotaxime (Claforan), cefotetan, cefoxitin (Mefoxin), cefpodoxime, cefprozil, ceftaroline (Teflaro), ceftazidime (Fortaz, Tazicef, in Avycaz), ceftibuten, ceftriaxone, cefuroxime (Ceftin, Zinacef), and cephalexin (Keflex); any other medications, or any of the ingredients in penicillin V potassium tablets or oral solution.
tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
tell your doctor if you currently have nausea or vomiting. Also, tell your doctor if you have or have ever had allergies, asthma, hay fever, or kidney disease.
tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking penicillin V potassium, call your doctor.
What SPECIAL DIETARY instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do IF I FORGET to take a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What SIDE EFFECTS can this medicine cause?
Penicillin V potassium may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
black, hairy tongue
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:
difficulty swallowing or breathing
swelling of the throat, tongue, or lips
a return of fever, sore throat, chills, or other signs of infection
severe diarrhea (watery or bloody stools) that may occur with or without fever and stomach cramps (may occur up to 2 months or more after your treatment)
Penicillin V potassium may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( Web Site ) or by phone (1-800-332-1088).
What should I know about STORAGE and DISPOSAL of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store the tablets at room temperature and away from excess heat and moisture (not in the bathroom). Keep the oral solution in the refrigerator, tightly closed, and dispose of any unused medication after 14 days. Do not freeze it.
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. Web Site
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( Web Site) for more information if you do not have access to a take-back program.
What should I do in case of OVERDOSE?
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at Web Site. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
What OTHER INFORMATION should I know?
Keep all appointments with your doctor and the laboratory.
Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the penicillin V potassium, call your doctor.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
¶ This branded product is no longer on the market. Generic alternatives may be available.
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