Medicine guide

Penicillin V Potassium

500 mg · Tablet, Film Coated

Prescription only
Penicillin-class Antibacterial

Active substance: Penicillin V Potassium
Used in: Antibiotics, antivirals and antifungals taken into the body
Made by: Redpharm Drug
Source: Official label

Quoted from the official source. Not yet reviewed by Mediclarum — the leaflet in your pack is authoritative.

At a glance

Quoted from the official label · 2026-07-14

What it is

Penicillin-class Antibacterial

Used for

To reduce the development of drug-resistant bacteria and maintain the effectiveness of penicillin V potassium and other antibacterial drugs, penicillin V potassium should be used only to treat or prevent…

The label’s usual adult dose

125 to 250 mg (200,000 to 400,000 units) every 6 to 8 hours for 10 days.

Full directions ↓

Do not take it if

A previous hypersensitivity reaction to any penicillin is a contraindication.

All warnings ↓

Good to know

Prescription only
FDA enforcement reports list no ongoing recall, and none from the last two years, for this product code · checked 2026-10-02

39other products contain Penicillin V Potassium — compare makers, forms and strengths

Every line above is selected, not written, from the official label. Nothing is reworded. DailyMed

What it is for

NOTE:

To reduce the development of drug-resistant bacteria and maintain the effectiveness of penicillin V potassium and other antibacterial drugs, penicillin V potassium should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.
When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.
In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
Penicillin V potassium tablets are indicated in the treatment of mild to moderately severe infections due to penicillin G-sensitive microorganisms.
Therapy should be guided by bacteriologic studies (including sensitivity tests) and by clinical response.
Severe pneumonia, empyema, bacteremia, pericarditis, meningitis, and arthritis should not be treated with penicillin V during the acute stage.
Indicated surgical procedures should be performed.
The following infections will usually respond to adequate dosage of penicillin V.
Streptococcal Infections (without bacteremia) Mild-to-moderate infections of the upper respiratory tract, scarlet fever, and mild erysipelas.
NOTE: Streptococci in groups A, C, G, H, L, and M are very sensitive to penicillin.
Other groups, including group D (enterococcus), are resistant.
Pneumococcal Infections Mild to moderately severe infections of the respiratory tract.
Staphylococcal infections – penicillin G-sensitive Mild infections of the skin and soft tissues.
Reports indicate an increasing number of strains of staphylococci resistant to penicillin G, emphasizing the need for culture and sensitivity studies in treating suspected staphylococcal infections.
Fusospirochetosis (Vincent’s gingivitis and pharyngitis) Mild to moderately severe infections of the oropharynx usually respond to therapy with oral penicillin.
Necessary dental care should be accomplished in infections involving the gum tissue.
Medical conditions in which oral penicillin therapy is indicated as prophylaxis:
For the prevention of recurrence following rheumatic fever and/or chorea:
Prophylaxis with oral penicillin on a continuing basis has proven effective in preventing recurrence of these conditions.
Although no controlled clinical efficacy studies have been conducted, penicillin V has been suggested by the American Heart Association and the American Dental Association for use as an oral regimen for prophylaxis against bacterial endocarditis in patients who have congenital heart disease or rheumatic or other acquired valvular heart disease when they undergo dental procedures and surgical procedures of the upper respiratory tract 1 .
Oral penicillin should not be used in those patients at particularly high risk for endocarditis (e.g., those with prosthetic heart valves or surgically constructed systemic pulmonary shunts).
Penicillin V should not be used as adjunctive prophylaxis for genitourinary instrumentation or surgery, lower-intestinal tract surgery, sigmoidoscopy, and childbirth.
Since it may happen that alpha hemolytic streptococci relatively resistant to penicillin may be found when patients are receiving continuous oral penicillin for secondary prevention of rheumatic fever, prophylactic agents other than penicillin may be chosen for these patients and prescribed in addition to their continuous rheumatic fever prophylactic regimen.
When selecting antibiotics for the prevention of bacterial endocarditis, the physician or dentist should read the full joint statement of the American Heart Association and the American Dental Association 1 .

From the official label · 2026-07-14 · DailyMed

How it works

From this product’s own US prescribing label.

Penicillin V exerts a bactericidal action against penicillin-sensitive microorganisms during the stage of active multiplication.
It acts through the inhibition of biosynthesis of cell-wall mucopeptide.

How it leaves the body

The drug is excreted as rapidly as it is absorbed in individuals with normal kidney function; however, recovery of the drug from the urine indicates that only about 25% of the dose given is absorbed.

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2026-07-14

Do not take it if

A previous hypersensitivity reaction to any penicillin is a contraindication.

Quoted from the official label, section “Contraindications”.

How to take it

These directions are for this exact strength and form. Another one is different.

The dosage of Penicillin V should be determined according to the sensitivity of the causative microorganisms and the severity of infection, and adjusted to the clinical response of the patient.
The usual dosage recommendations for
adults and children 12 years and over are as follows:
Streptococcal Infections Mild to moderately severe - of the upper respiratory tract and including scarlet fever and erysipelas:
125 to 250 mg (200,000 to 400,000 units) every 6 to 8 hours for 10 days.
Pneumococcal Infections Mild to moderately severe - of the respiratory tract, including otitis media:
250 to 500 mg (400,000 to 800,000 units) every 6 hours until the patient has been afebrile for at least 2 days.
Staphylococcal Infections Mild infections of skin and soft tissue (culture and sensitive tests should be performed):
250 to 500 mg (400,000 to 800,000 units) every 6 to 8 hours.
Fusospirochetosis (Vincent’s infection) of the oropharynx.
Mild to moderately severe infections:
250 to 500 mg (400,000 to 800,000 units) every 6 to 8 hours.
For the prevention of recurrence following rheumatic fever and/or chorea:
125 mg to 250 mg (200,000 to 400,000 units) twice daily on a continuing basis.
For prophylaxis against bacterial endocarditis 1 in patients with congenital heart disease or rheumatic or other acquired valvular heart disease when undergoing dental procedures or surgical procedures of the upper respiratory tract:
2 gram of penicillin V (1 gram for
children under 60 lbs.) 1 hour before the procedure, and then, 1 gram (500 mg for
children under 60 lbs.) 6 hours later.

Quoted from the official label, section “Dosage & Administration”.

Other warnings

SERIOUS AND OCCASIONALLY FATAL HYPERSENSITIVITY (anaphylactic) REACTIONS HAVE BEEN REPORTED IN PATIENTS ON PENICILLIN THERAPY.
THESE REACTIONS ARE MORE LIKELY TO OCCUR IN INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY AND/OR A HISTORY OF SENSITIVITY TO MULTIPLE ALLERGENS.
THERE HAVE BEEN REPORTS OF INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY WHO HAVE EXPERIENCED SEVERE REACTIONS WHEN TREATED WITH CEPHALOSPORINS.
BEFORE INITIATING THERAPY WITH PENICILLIN V POTASSIUM TABLETS, CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, OR OTHER ALLERGENS.
IF AN ALLERGIC REACTION OCCURS, PENICILLIN V POTASSIUM TABLETS SHOULD BE DISCONTINUED AND APPROPRIATE THERAPY INSTITUTED.
SERIOUS ANAPHYLACTIC REACTIONS REQUIRE IMMEDIATE EMERGENCY TREATMENT WITH EPINEPHRINE.
OXYGEN, INTRAVENOUS STEROIDS, AND AIRWAY MANAGEMENT, INCLUDING INTUBATION, SHOULD ALSO BE ADMINISTERED AS INDICATED.
Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including penicillin V potassium tablets, and may range in severity from mild diarrhea to fatal colitis.
Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile .
C. difficile produces toxins A and B which contribute to the development of CDAD.
Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy.
CDAD must be considered in all patients who present with diarrhea following antibiotic use.
Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued.
Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated.
Penicillin should be used with caution in individuals with histories of significant allergies and/or asthma.
General Prescribing penicillin V potassium in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
The oral route of administration should not be relied upon in patients with severe illness, or with nausea, vomiting, gastric dilatation, cardiospasm, or intestinal hypermotility.
Occasionally patients will not absorb therapeutic amounts of orally administered penicillin.
In streptococcal infections, therapy must be sufficient to eliminate the organism (10-day minimum); otherwise the sequelae of streptococcal disease may occur.
Cultures should be taken following completion of treatment to determine whether streptococci have been eradicated.
Prolonged use of antibiotics may promote the overgrowth of nonsusceptible organisms, including fungi.
Should superinfection occur, appropriate measures should be taken.
Information for Patients Patients should be counseled that antibacterial drugs including penicillin V potassium should only be used to treat bacterial infections.
General Prescribing penicillin V potassium in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
The oral route of administration should not be relied upon in patients with severe illness, or with nausea, vomiting, gastric dilatation, cardiospasm, or intestinal hypermotility.
Occasionally patients will not absorb therapeutic amounts of orally administered penicillin.
In streptococcal infections, therapy must be sufficient to eliminate the organism (10-day minimum); otherwise the sequelae of streptococcal disease may occur.
Cultures should be taken following completion of treatment to determine whether streptococci have been eradicated.
Prolonged use of antibiotics may promote the overgrowth of nonsusceptible organisms, including fungi.
Should superinfection occur, appropriate measures should be taken.

Quoted from the official label, section “Warnings”.

Side effects

Although the incidence of reactions to oral penicillins has been reported with much less frequency than following parenteral therapy, it should be remembered that all degrees of hypersensitivity, including fatal anaphylaxis, have been reported with oral penicillin.
The most common reactions to oral penicillin are nausea, vomiting, epigastric distress, diarrhea, and black hairy tongue.
The hypersensitivity reactions reported are skin eruptions (maculopapular to exfoliative dermatitis), urticaria and other serum-sickness like reactions, laryngeal edema, and anaphylaxis.
Fever and eosinophilia may frequently be the only reaction observed.
Hemolytic anemia, leukopenia, thrombocytopenia, neuropathy, and nephropathy are infrequent reactions and usually associated with high doses of parenteral penicillin.

Quoted from the official label, section “Adverse Reactions”.

What to discuss with your doctor

Patients should be counseled that antibacterial drugs including penicillin V potassium should only be used to treat bacterial infections.
They do not treat viral infections (e.g., the common cold).
When penicillin V potassium is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed.
Skipping doses or not completing the full course of therapy may:
(1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by penicillin V potassium or other antibacterial drugs in the future.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued.
Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic.
If this occurs, patients should contact their physician as soon as possible.

Quoted from the official label, section “Patient Counseling Information”.

What it looks like and how it is packed

Penicillin V Potassium Tablets USP, 250 mg (400,000 units) are white to off-white, round shaped, biconvex, film-coated tablets debossed with ‘E’ and ‘84’ on one side and break line on the other side.
Bottles of 100 NDC 16714-234-01 Bottles of 1,000 NDC 16714-234-02 Penicillin V Potassium Tablets USP, 500 mg (800,000 units) are white to off-white, capsule shaped, film-coated tablets, debossed with ‘E’ and a break line on one side and ‘8’ and ‘5’ separated with a break line on the other side.
Bottles of 100 NDC 16714-235-01 Bottles of 1,000 NDC 16714-235-02
Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].
Dispense in a tight container, as defined in the USP.
Keep tightly closed.
Keep out of reach of children.

Quoted from the official label, section “How Supplied”.

What is in it

Penicillin V is the phenoxymethyl analog of penicillin G.
Penicillin V potassium is the potassium salt of penicillin V.
Penicillin V potassium tablets, for oral administration, contain 250 mg (400,000 units) or 500 mg (800,000 units).
The 250 mg tablet is equivalent to 250 mg (400,000 units) penicillin V and the 500 mg tablet is equivalent to 500 mg (800,000 units) penicillin V.
In addition, each tablet contains the following inactive ingredients:
povidone, microcrystalline cellulose, talc, colloidal silicon dioxide, magnesium stearate, hypromellose, polyethylene glycol, and titanium dioxide.
Chemical Structure

Quoted from the official label, section “Description”.

Ingredients people check for

Lactose, gluten, dyes, sugars and other ingredients that matter with an allergy, intolerance or diet — as this product’s FDA label lists them.

Titanium dioxidetitanium dioxideA whitening agent no longer allowed in food in the EU (E171).

Quoted from the FDA label. A label that does not name an ingredient is not a guarantee that the product is free of it, and formulations change. With an allergy, check the pack and ask a pharmacist.

Every version of this medicine (15)

The same active substance, strength and kind of form, from every company that sells it — with what each label lists.

Showing 15 of 15

Same active substance, strength and form in other countries

Matched on active substance, strength and kind of form only. This is not a statement that the products are equivalent or interchangeable: other ingredients, release and approved uses can differ — ask a pharmacist before swapping.

Medicine passport: one printable page to show a pharmacist abroad

CanadaNo exact match for this strength and form

Every strength and form (1)

Details

Made by	Redpharm Drug
Active substance	Penicillin V Potassium
Used in	Antibiotics, antivirals and antifungals taken into the body
Strength	500 mg
Form	Tablet, Film Coated
Route	Oral
Packs	20 TABLET, FILM COATED in 1 BOTTLE · 30 TABLET, FILM COATED in 1 BOTTLE
NDC	67296-2261

Source: NDC Directory · 2026-09-13 · not reviewed by a clinician

Source: US Food and Drug Administration, NDC Directory. Reuse terms: US government work (FDA).

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Other strengths and forms

40 products are sold under this name. Grouped by form; a number on a strength means several companies make it.

Tablet, Film Coated25 products
- 250 mg12
  250 mg · 12 companies
  +4 more
- 500 mg13
  500 mg · 13 companies
  +5 more
Powder, for Solution9 products
- 125 mg/5mL3
  125 mg/5mL · 3 companies
- 250 mg/5mL6
  250 mg/5mL · 6 companies
Tablet6 products
- 250 mg4
  250 mg · 4 companies
- 500 mg2
  500 mg · 2 companies
  - Chartwell RX, LLC
  - Teva Pharmaceuticals USA, Inc.

Same active substance

These contain the same substance. That does not mean one can replace another — ask a pharmacist.

See every product with Penicillin V Potassium