Penicillin Vk 250mg Tablets
It is used to treat or prevent bacterial infections.
Drug Class
Antibiotic
Pharmacologic Class
Beta-lactam antibiotic; Penicillin
Pregnancy Category
Category B
FDA Approved
Sep 1959
DEA Schedule
Not Controlled
Overview
What is this medicine?
Penicillin V Potassium is an antibiotic used to treat various bacterial infections, such as strep throat, ear infections, and pneumonia. It works by killing the bacteria that cause these infections.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely.
Take your medication on an empty stomach, either 1 hour before or 2 hours after meals.
If your medication causes stomach upset, you can take it with food to help alleviate this issue.
Continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling well.
Storing and Disposing of Your Medication
To ensure your medication remains effective and safe:
Store it at room temperature in a dry place, avoiding bathrooms.
Keep all medications in a secure location, out of the reach of children and pets.
Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist or healthcare provider.
If you have questions about disposing of your medication, consult your pharmacist. You may also have access to drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Take the missed dose as soon as you remember.
However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule.
Do not take two doses at the same time or take extra doses to make up for the missed one.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely.
Take your medication on an empty stomach, either 1 hour before or 2 hours after meals.
If your medication causes stomach upset, you can take it with food to help alleviate this issue.
Continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling well.
Storing and Disposing of Your Medication
To ensure your medication remains effective and safe:
Store it at room temperature in a dry place, avoiding bathrooms.
Keep all medications in a secure location, out of the reach of children and pets.
Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist or healthcare provider.
If you have questions about disposing of your medication, consult your pharmacist. You may also have access to drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Take the missed dose as soon as you remember.
However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule.
Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take the medication exactly as prescribed by your doctor, even if you start feeling better. Do not skip doses or stop taking it early, as this can lead to antibiotic resistance and recurrence of infection.
- Take on an empty stomach (1 hour before or 2 hours after meals) with a full glass of water for best absorption.
- Do not share this medication with others.
- If you develop severe diarrhea, especially if it's watery or bloody, contact your doctor immediately. Do not take anti-diarrhea medications without consulting your doctor.
- Inform your doctor or pharmacist about all other medications, supplements, and herbal products you are taking.
Available Forms & Alternatives
Available Strengths:
- Penicillin Vk 125mg/5ml Soln 100ml
- Penicillin Vk 125mg/5ml Soln 200ml
- Penicillin G Sodium 5 Million Units
- Penicillin Vk 250mg/5ml Soln 100ml
- Penicillin Vk 250mg/5ml Soln 200ml
- Penicillin Gk 5mu Inj, 1 Vial
- Penicillin Gk 20mu Inj, 1 Vial
- Penicillin Vk 250mg Tablets
- Penicillin Vk 500mg Tablets
- Penicillin Gk 5mu Inj, 1 Vial
- Penicillin Vk 500mg Tablets
- Penicillin Vk 250mg Tablets
- Penicillin Vk 250mg Tablets
- Penicillin Gk 20mu Inj, 1 Vial
- Penicillin Gk 20mu Inj, 1 Vial
Dosing & Administration
Adult Dosing
Standard Dose:
250 mg to 500 mg orally every 6 to 8 hours
Dose Range:
250 - 500 mg
Condition-Specific Dosing:
Streptococcal Pharyngitis:
250 mg every 6-8 hours for 10 days or 500 mg every 12 hours for 10 days
Pneumococcal Infections:
250 mg to 500 mg every 6 hours until afebrile for at least 2 days
Staphylococcal Infections (mild):
250 mg to 500 mg every 6 to 8 hours
Fusospirochetosis (Vincent's Infection):
250 mg to 500 mg every 6 to 8 hours
Prevention of Rheumatic Fever Recurrence:
250 mg twice daily continuously
Pediatric Dosing
Neonatal:
Not established for routine use; consult specialist
Infant:
25-50 mg/kg/day orally in 3-4 divided doses (max 500 mg/dose)
Child:
25-50 mg/kg/day orally in 3-4 divided doses (max 3 g/day); for streptococcal pharyngitis: 250 mg 2-3 times daily for 10 days
Adolescent:
Same as adult dosing for specific indications
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed (CrCl 10-50 mL/min)
Severe:
Reduce dose or extend interval (e.g., 250 mg every 8-12 hours for CrCl < 10 mL/min)
Dialysis:
Administer dose after dialysis; supplemental dose may be needed
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed (primarily renally eliminated)
Pharmacology
Mechanism of Action
Penicillin V potassium is a bactericidal antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs) located inside the bacterial cell wall. This binding prevents the cross-linking of peptidoglycan units, leading to defective cell walls, increased osmotic pressure, and ultimately cell lysis and bacterial death.
Pharmacokinetics
Absorption:
Bioavailability:
60-73%
Tmax:
0.5-1 hour
FoodEffect:
Food decreases absorption; administer 1 hour before or 2 hours after meals for optimal absorption.
Distribution:
Vd:
0.3-0.4 L/kg
ProteinBinding:
75-89%
CnssPenetration:
Limited (unless meninges are inflamed)
Elimination:
HalfLife:
0.5-1 hour
Clearance:
Not available
ExcretionRoute:
Renal (tubular secretion and glomerular filtration)
Unchanged:
25-50% (within 6 hours)
Pharmacodynamics
OnsetOfAction:
Rapid
PeakEffect:
Within 1 hour of oral administration
DurationOfAction:
Dependent on dosing interval (typically 6-8 hours due to short half-life)
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Attention Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
In rare cases, allergic reactions can be fatal.
Diarrhea and Bowel Problems
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form of diarrhea called C. diff-associated diarrhea (CDAD) may occur. This condition can lead to a life-threatening bowel problem. CDAD may develop during or several months after taking antibiotics. If you experience any of the following symptoms, contact your doctor immediately:
Stomach pain
Cramps
Very loose, watery, or bloody stools
Before treating diarrhea, consult your doctor.
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical help:
Upset stomach or vomiting
Stomach pain or diarrhea
Black, hairy tongue
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, consult your doctor.
Reporting Side Effects
For medical advice about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
In rare cases, allergic reactions can be fatal.
Diarrhea and Bowel Problems
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form of diarrhea called C. diff-associated diarrhea (CDAD) may occur. This condition can lead to a life-threatening bowel problem. CDAD may develop during or several months after taking antibiotics. If you experience any of the following symptoms, contact your doctor immediately:
Stomach pain
Cramps
Very loose, watery, or bloody stools
Before treating diarrhea, consult your doctor.
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical help:
Upset stomach or vomiting
Stomach pain or diarrhea
Black, hairy tongue
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, consult your doctor.
Reporting Side Effects
For medical advice about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Signs of allergic reaction: rash, hives, itching, swelling (especially of the face, lips, or tongue), difficulty breathing or swallowing. Seek immediate medical attention if these occur.
- Severe or persistent diarrhea, especially if accompanied by fever or abdominal cramps (may indicate C. difficile infection).
- Unusual bruising or bleeding.
- Yellowing of skin or eyes (jaundice).
- Dark urine or pale stools.
- Persistent sore throat or fever (may indicate new infection).
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Gastrointestinal (GI) tract problems, such as an enlarged stomach or esophagus spasms
+ Severe illness
+ Diarrhea, upset stomach, or vomiting
This list is not exhaustive, and it is crucial to discuss all your health problems with your doctor.
Additionally, provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Natural products and vitamins you are using
* Any health problems you have
This information will help your doctor determine if it is safe for you to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Gastrointestinal (GI) tract problems, such as an enlarged stomach or esophagus spasms
+ Severe illness
+ Diarrhea, upset stomach, or vomiting
This list is not exhaustive, and it is crucial to discuss all your health problems with your doctor.
Additionally, provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Natural products and vitamins you are using
* Any health problems you have
This information will help your doctor determine if it is safe for you to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you are taking this drug for an extended period, your doctor may recommend regular blood tests to monitor your condition. Be sure to discuss this with your doctor.
Do not take this medication for longer than prescribed, as this may increase the risk of a second infection. If you become pregnant, plan to become pregnant, or are breastfeeding, notify your doctor immediately. You and your doctor will need to carefully weigh the benefits and risks of taking this medication to ensure the best possible outcome for you and your baby.
Do not take this medication for longer than prescribed, as this may increase the risk of a second infection. If you become pregnant, plan to become pregnant, or are breastfeeding, notify your doctor immediately. You and your doctor will need to carefully weigh the benefits and risks of taking this medication to ensure the best possible outcome for you and your baby.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Neuromuscular hyperexcitability (e.g., twitching, seizures) - rare, typically with very high doses or severe renal impairment
What to Do:
Call 1-800-222-1222 (Poison Control Center) immediately or seek emergency medical attention. Treatment is generally supportive; hemodialysis may be used in severe cases with renal impairment.
Drug Interactions
Major Interactions
- Methotrexate (increased methotrexate toxicity due to decreased renal clearance)
- Tetracyclines (may antagonize bactericidal effect of penicillin)
Moderate Interactions
- Probenecid (increases penicillin levels by decreasing renal tubular secretion)
- Warfarin (potential for enhanced anticoagulant effect, monitor INR)
- Oral Contraceptives (theoretical reduction in efficacy, though clinical significance is debated and generally not considered significant enough to warrant additional contraception)
Minor Interactions
- Live bacterial vaccines (e.g., typhoid vaccine; antibiotics may reduce vaccine efficacy)
Monitoring
Baseline Monitoring
Allergy history (especially to penicillins or cephalosporins)
Rationale: To prevent severe hypersensitivity reactions (e.g., anaphylaxis)
Timing: Prior to initiation of therapy
Renal function (CrCl, BUN, creatinine)
Rationale: To guide dose adjustment in patients with renal impairment
Timing: Prior to initiation, especially in elderly or those with known renal issues
Routine Monitoring
Clinical response to therapy (e.g., fever, symptom resolution)
Frequency: Daily during acute infection
Target: Resolution of signs/symptoms of infection
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure or resistance
Signs of hypersensitivity (rash, itching, swelling, dyspnea)
Frequency: Daily, especially during initial days of therapy
Target: Absence of allergic reaction
Action Threshold: Any sign of allergic reaction requires immediate discontinuation
Gastrointestinal symptoms (nausea, vomiting, diarrhea)
Frequency: Daily
Target: Absence or mild GI upset
Action Threshold: Severe or persistent diarrhea may indicate C. difficile infection
Symptom Monitoring
- Rash
- Hives
- Itching
- Swelling of face/lips/tongue
- Difficulty breathing or swallowing
- Severe diarrhea (especially if bloody or watery)
- Abdominal pain/cramping
- Nausea
- Vomiting
- Oral thrush (white patches in mouth)
- Vaginal yeast infection (itching, discharge)
Special Patient Groups
Pregnancy
Generally considered safe for use during pregnancy. Penicillin V potassium is classified as Pregnancy Category B, meaning animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women, or animal studies have shown an adverse effect but human studies have not.
Trimester-Specific Risks:
First Trimester:
Low risk; no evidence of increased risk of congenital anomalies.
Second Trimester:
Low risk.
Third Trimester:
Low risk.
Lactation
Considered compatible with breastfeeding. Penicillin V is excreted into breast milk in small amounts. The amount ingested by the infant is generally too low to cause harm, but theoretical risks include alteration of bowel flora, diarrhea, or allergic sensitization in the infant.
Infant Risk:
Low risk (L1 - Safest)
Pediatric Use
Dosing is weight-based for infants and children. Generally well-tolerated. Close monitoring for allergic reactions is important. Not recommended for neonates without specialist consultation.
Geriatric Use
No specific dose adjustment needed based on age alone, but dose adjustments may be necessary for age-related decline in renal function. Elderly patients may be more susceptible to adverse effects like C. difficile-associated diarrhea.
Clinical Information
Clinical Pearls
- Penicillin V potassium is the oral penicillin of choice for streptococcal pharyngitis due to its narrow spectrum and efficacy.
- Always complete the full course of therapy, even if symptoms improve, to prevent resistance and relapse.
- Advise patients to take on an empty stomach for optimal absorption, though it can be taken with food if GI upset occurs (absorption may be slightly reduced).
- Counsel patients on the importance of reporting any signs of allergic reaction immediately.
- It is not effective against beta-lactamase producing bacteria.
Alternative Therapies
- Amoxicillin (for many similar indications, broader spectrum)
- Cephalexin (a first-generation cephalosporin, often used for similar indications in penicillin-allergic patients, but cross-reactivity can occur)
- Azithromycin (macrolide, for penicillin-allergic patients, especially for respiratory tract infections)
- Clindamycin (for certain anaerobic infections or in penicillin-allergic patients)
Cost & Coverage
Average Cost:
$10 - $30 per 30 tablets (250mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 (Preferred Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication, including the amount taken and the time it happened, to ensure you receive the best possible care.