Penicillin V potassium is one version of penicillin, the oldest and most recognizable antibiotic. Doctors use it for a variety of bacterial infections, particularly strep and staph infections. People take this generic prescription drug by mouth as a tablet or oral solution.
Check our best Penicillin V Potassium prices
No brand-name versions
Penicillin V potassium
Treats bacterial infections
Antibiotic
Tablet, oral solution (liquid)
By mouth
Penicillin V potassium treats a variety of mild to moderately severe bacterial infections of the skin, upper respiratory tract, lungs, and soft tissues.
Tablet
250 mg
500 mg
Oral solution
125 mg/5 mL
250 mg/5 mL
For mild to moderately severe streptococcal infections: 125 to 250 mg every six to eight hours for 10 days
For mild to moderately severe pneumococcal infections of the respiratory tract or ears: 250 to 500 mg every six hours until the patient no longer has a fever for at least two days
For mild staphylococcal infections of the skin or soft tissues: 250 to 500 mg every six to eight hours
For mild to moderately severe trench mouth (fusospirochetosis): 250 to 500 mg every six to eight hours
Penicillin V Potassium
100ml of 125mg/5ml bottle
Penicillin V Potassium
100ml of 250mg/5ml bottle
Penicillin V Potassium
200ml of 125mg/5ml bottle
Penicillin V Potassium
200ml of 250mg/5ml bottle
Penicillin V Potassium
250mg tablet
Penicillin V Potassium
500mg tablet
Take this medicine as directed.
Take all of the penicillin in your prescription to clear up the infection, even if you feel better after the first few doses.
Take the tablet or oral solution on an empty stomach.
If the dose causes stomach problems, it’s okay to take it with food.
Swallow the tablet whole with a drink of water.
Use an oral dosing syringe to measure doses of the oral solution. Do not use kitchen measuring devices or tableware.
Store the tablets at room temperature in a tightly closed container.
Store the oral solution in the refrigerator. Discard any medicine you have not used after 14 days.
Take a missed dose as soon as it’s remembered.
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.
This medicine is not right for everyone.
Do not use it if you have had an allergic reaction to any type of penicillin.
Tell any doctor or other healthcare provider who treats you that you are using this medicine.
The doctor may require follow-up visits to monitor the effectiveness of treatment. Keep all appointments.
Before taking penicillin, inform the prescriber if you are pregnant, breastfeeding, or have:
Known allergies to penicillin
Known allergies to cephalosporin antibiotics
Multiple or significant allergies
Asthma
This medicine can cause severe diarrhea during or up to two months after treatment ends. Call the 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.
Call the doctor if your symptoms do not improve or if they get worse.
Use penicillin V potassium to only treat the bacterial infection it was prescribed for. Do not use it for viral or other infections.
Before taking penicillin V potassium, tell the prescribing clinician about all the prescription drugs and over-the-counter medications being used, particularly:
Methotrexate
Warfarin
Birth control pills, implants, or shots may not work as well while you are using penicillin. Ask the prescriber if you need to use backup birth control.
If a colonoscopy or similar procedure is scheduled during penicillin treatment, tell the clinic or doctor about your penicillin treatment. Certain bowel prep laxatives may not work as well when people are taking antibiotics.
Talk to a doctor if you notice any signs or symptoms of a possible serious side effect, including:
Severe diarrhea, bloody diarrhea, fever, stomach cramps
Blistering, peeling, red skin rash
Allergic reaction: Hives, rash, fever, flushing, joint pain, swelling in your face, mouth, throat, or voice box, noisy breathing, hoarseness, difficulty breathing, dizziness, faintness
Nausea
Vomiting
Black, hairy tongue
Stomach distress
Mild diarrhea
Penicillin V potassium tablet/powder for solution prescribing information, DailyMed (NIH National Library of Medicine)
Veetids drug summary, Prescriber’s Digital Reference (PDR)
Health education, drug info, wellness & more
SingleCare is a prescription discount service that offers free coupons on thousands of prescription drugs. It can be used whether you have insurance, Medicare, Medicaid, or none of the above, but it cannot be combined with insurance.
SingleCare provides transparent drug pricing, so you can compare discounts at pharmacies near you. Browse singlecare.com to find drug discounts, helpful information about your prescription, and resources to help you make informed health decisions.
Prescription savings vary by prescription and by pharmacy, and may reach up to 80% off cash price. This is a medical discount plan. This is NOT insurance. This program offers you the opportunity to locate providers of various types of medical services who will offer their services to you at discounted rates. The range of discounts for medical or ancillary services provided under the plan will vary depending on the type of provider and service received. You are fully responsible for paying for all health care services but will be entitled to receive a discount from those health care providers in accordance with the specific pre-negotiated discounted fee schedule. This program does not guarantee the quality of the services or procedures offered by the providers. Except for prescription drugs which you will pay directly to the pharmacy at the time of purchase, all other services received through a program provider will be charged to the credit card on file in your member account. The charge will include an administrative fee for use of the program. Towers Administrators LLC is the licensed discount medical plan organization with its administrative office located at 4510 Cox Road, Suite 111, Glen Allen, VA 23060. SingleCare Services, LLC is the marketer of the discount medical plan organization including its website, singlecare.com, with its corporate office located at 99 High Street, Suite 2800, Boston, MA 02110. For additional information, including an up-to-date list of providers, or assistance with any issue related to program membership, please contact member support any time at www.singlecare.com, or by calling toll-free 844-234-3057, 24 hours, 7 days a week (except major holidays). Pharmacy names, logos, brands, and other trademarks are the property of their respective owners.
Blog articles are not medical advice. They are intended for general informational purposes and are not meant to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. If you think you may have a medical emergency, immediately call your physician or dial 911.
© 2025 SingleCare Administrators. All rights reserved
© 2025 SingleCare Administrators. All rights reserved