Penicillin V potassium is the potassium salt of penicillin V. This chemically improved form combines acid stability with immediate solubility and rapid absorption. It is designated 4-thia-1-azabicyclo[3.2.0]-heptane-2-carboxylic acid, 3,3 -dimethyl-7-oxo-6-[(phenoxyacetyl)amino]-, monopotassium salt, [2S-(2a,5a,6b)]-. The empirical formula is C₁₆H₁₇KN₂O₅S, and the molecular weight is 388.48.

Each tablet contains penicillin V potassium equivalent to 250 mg (400,000 units) or 500 mg (800,000 units) penicillin V. The tablets also contain lactose, magnesium stearate, povidone, starch, stearic acid, and other inactive ingredients.

After being mixed as directed, each 5 ml of the oral solution will contain penicillin V potassium equivalent to 250 mg (400,000 units) penicillin V. The suspension also contains citric acid, F D & C Red No. 40, flavors, saccharin, sodium citrate, and sucrose.

The potassium content of the tablets and oral solution is listed below (TABLE 1).

Last updated on RxList: 12/8/2004

Penicillin V potassium is indicated in the treatment of mild to moderately severe infections due to microorganisms whose susceptibility to penicillin G is within the range of serum levels common to this particular dosage form. Therapy should be guided by bacteriologic studies (including susceptibility tests) and by clinical response.

NOTE: 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 groups A, C, G, H, L, and M are very susceptible to penicillin. Other groups, including group D (enterococcus), are resistant.

Pneumococcal Infections: Mild to moderately severe infections of the respiratory tract.

Staphylococcal Infections Susceptible to Penicillin G: Mild infections of the skin and soft tissues.

NOTE: Reports indicate an increasing number of strains of staphylococci resistant to penicillin G, which emphasizes the need for culture and susceptibility 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.

NOTE: Necessary dental care should be accomplished in infections involving the gum tissue.

Medical Conditions in Which Oral Penicillin Therapy Is Indicated as Prophylaxis: To prevent recurrence following rheumatic fever and/or chorea. Prophylaxis with oral penicillin on a continuing basis has proved 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 with congenital heart disease or rheumatic or other acquired valvular heart disease when they undergo dental procedures and surgical procedures of the respiratory tract.¹

Since a-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 prophylactic regimen for rheumatic fever.

Oral penicillin should not be used as adjunctive prophylaxis for genitourinary instrumentation or surgery, lower intestinal tract surgery, sigmoidoscopy, and childbirth.

NOTE: 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

The dosage of penicillin V potassium should be determined according to the susceptibility of the causative microorganism and the severity of infection and should be 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 infections of the upper respiratory tract, including scarlet fever and mild erysipelas: 200,000 to 500,000 units every 6 to 8 hours for 10 days.

Pneumococcal Infections: Mild to moderately severe infections of the respiratory tract, including otitis media: 400,000 to 500,000 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 susceptibility tests should be performed): 400,000 to 500,000 units every 6 to 8 hours.

Fusospirochetosis (Vincent's Infection) of the Oropharynx: Mild to moderately severe infections: 400,000 to 500,000 units every 6 to 8 hours.

Prophylaxis in the Following Conditions: To prevent recurrence following rheumatic fever and/or chorea: 200,000 to 250,000 units twice daily on a continuing basis.

For prophylaxis against bacterial endocarditis¹in 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, 1 of 2 regimens may be selected:

(1) For the oral regimen, the usual adult dosage is 2 g of penicillin V (1 g for children less than 30 kg) 1 hour before the procedure and then 1 g (500 mg for children less than 30 kg) 6 hours later.

(2) For patients unable to take oral antibiotics, 2,000,000 units of aqueous penicillin G (50,000 units/kg for children) IV or IM may be substituted 30 to 60 minutes before the procedure and 1,000,000 units (25,000 units/kg for children) 6 hours later.

For patients with prosthetic valves and for those at highest risk for endocarditis, ampicillin, 1 to 2 g (50 mg/kg for children), plus gentamicin, 1.5 mg/kg (2 mg/kg for children), IM or IV, may be given one- half hour prior to the procedure, followed by 1 g of oral penicillin V 6 hours later. Alternatively, the parenteral regimen should be repeated once every 8 hours later.

Children's antibiotic dosages should not exceed the maximum adult doses.

NOTE: Therapy for children under 12 years of age is calculated on the basis of body weight. For infants and small children, the suggested daily dose is 25,000 to 90,000 units (15 to 50 mg)/kg in 3 to 6 divided doses.

After being mixed, the solution should be stored in a refrigerator. It may be kept for 14 days without significant loss of potency. Shake well before using. Keep tightly closed.

Tablets should be stored at controlled room temperature, 59° to 86°F (15° to 30°C).

REFERENCES

1. Dajani AS, Bisno AL, et al: Prevention of bacterial endocarditis. Recommendations by the American Heart Association.JAMA, 1990;264:2919.

Last updated on RxList: 12/8/2004

Although reactions have been reported much less frequently after oral than after parenteral penicillin therapy, it should be remembered that all degrees of hypersensitivity, including fatal anaphylaxis, have been observed with oral penicillin.

The most common reactions to oral penicillin are nausea, vomiting, epigastric distress, diarrhea, and black, hairy tongue. The hypersensitivity reactions noted are skin eruptions (ranging from maculopapular to exfoliative dermatitis); urticaria; reactions resembling serum sickness, including chills, fever, edema, arthralgia, and prostration; laryngeal edema; and anaphylaxis. Fever and eosinophilia may frequently be the only reactions observed. Hemolytic anemia, leukopenia, thrombocytopenia, neuropathy, and nephropathy are infrequent reactions and are usually associated with high doses of parenteral penicillin.

No information provided.

Last updated on RxList: 12/8/2004

SERIOUS AND OCCASIONALLY FATAL HYPERSENSITIVITY (ANAPHYLACTIC) REACTIONS HAVE BEEN REPORTED IN PATIENTS RECEIVING 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, CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, OR OTHER ALLERGENS. IF AN ALLERGIC REACTION OCCURS, PENICILLIN V POTASSIUM 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 ADMINISTRATED AS INDICATED.

Pseudomembranous colitis has been reported with nearly all antibacterial agents including penicillins, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.

Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is one primary cause of "antibiotic-associated colitis."

After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an antibacterial drug clinically effective against C. difficile colitis.

Penicillin should be used with caution in individuals with histories of significant allergies and/or asthma.

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.

Occasional patients will not absorb therapeutic amounts of orally administered penicillin.

In streptococcal infections, therapy must be sufficient to eliminate the organism (a minimum of 10 days); 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. If superinfection occurs, appropriate measures should be taken.

Last updated on RxList: 12/8/2004

Signs and Symptoms: Symptoms of large oral overdose of penicillin may cause nausea, vomiting, stomach pain, diarrhea, and, in rare cases, major motor seizures. If other symptoms are present, consideration must also be given to the possibility of an allergic reaction or symptoms secondary to a concurrent medication or other underlying disease state, especially in adults.

Treatment: To obtain up-to-date information about the treatment of overdose, a good resource is your certified Regional Poison Control Center. Telephone numbers of certified poison control centers are listed in Physicians GenR_x. In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in your patient.

Ensure adequate ventilation and protect the patient's airway while attempting to limit drug absorption. In oral overdosage, consideration must be given to emesis or lavage to evacuate the stomach, and administration of activated charcoal by mouth or via lavage tube with a cathartic such as sorbitol may hasten drug elimination. Penicillin may be removed by hemodialysis. No specific antidote is known to be effective.

A previous hypersensitivity reaction to any penicillin is a contraindication.

Last updated on RxList: 12/8/2004

Penicillin V potassium is bactericidal against penicillin-susceptible microorganisms during the stage of active multiplication. It produces its effect by inhibiting biosynthesis of cell-wall mucopeptide. It is not active against the penicillinase-producing bacteria, which include many strains of staphylococci. The drug exerts high in vitro activity against staphylococci (except penicillinase-producing strains), streptococci (groups A, C, G, H, L, and M), and pneumococci. Other organisms susceptible in vitro to penicillin V areCorynebacterium diphtheriae, Bacillus anthracis, clostridia,Actinomyces bovis, Streptobacillus moniliformis, Listeria monocytogenes, Leptospira, and Neisseria gonorrhoeae.Treponema pallidium is extremely susceptible.

Penicillin V potassium has the distinct advantage over penicillin G in being resistant to inactivation by gastric acid. It may be given with meals; however, blood levels are slightly higher when the drug is given on an empty stomach. Average blood levels are 2 to 5 times higher than those following the same dose of oral penicillin G and also show much less individual variation.

Once absorbed, about 80% of penicillin V potassium is bound to serum protein. Tissue levels are highest in the kidneys, and lesser amounts appear in the liver, skin, and intestines. Small concentrations are found in all other body tissues and the cerebrospinal fluid. 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. In neonates, young infants, and individuals with impaired kidney function, excretion is considerably delayed.

Last updated on RxList: 12/8/2004

Penicillin V potassium is an antibiotic used to treat a variety of infections, most notably strep throat. This drug is also used to prevent infections (bacterial endocarditis) in patients with congenital heart disease or rheumatic or other acquired valvular heart disease. Penicillin is taken before dental procedures and surgical procedures in these patients. This drug should not be used by those with allergies to penicillin and you should consult with your pharmacist or physician if you are allergic to penicillin before taking this medication. The most common side effects from penicillin include: nausea, vomiting, epigastric distress, and diarrhea. Because this medication is used to treat infections, it should be taken as prescribed. Even if your symptoms are better, the entire supply of medication should be taken to ensure the infection is cured. Liquid forms of penicillin must be refrigerated and shaken before administered.

Last updated on RxList: 12/8/2004

IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.

PENICILLIN V POTASSIUM - ORAL SOLIDS

(pen-ih-SILL-in VEE poh-TASS-ee-um)

COMMON BRAND NAME(S): Beepen VK, Ledercillin VK, Pen-Vee K, V-Cillin K, Veetids

USES: Penicillin is an antibiotic used to treat and prevent a wide variety of bacterial infections. It works by stopping the growth of bacteria.

This antibiotic treats and prevents only bacterial infections. It will not work for virus infections (such as the common cold, flu). Unnecessary use or overuse of any antibiotic can lead to its decreased effectiveness.

HOW TO USE: Take this medication by mouth as directed by your doctor. This medication may be taken with or without food. However, penicillin is best absorbed when taken on an empty stomach (1 hour before or 2 hours after meals).

The dosage is based on your medical condition and response to treatment.

Antibiotics work best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals.

Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria to continue to grow, which may result in a return of the infection.

Tell your doctor if your condition persists or worsens.

SIDE EFFECTS: Upset stomach, nausea, vomiting, diarrhea, and mouth sores may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Although this effect is uncommon, you may develop a black, "hairy" tongue while taking this medication. This effect is harmless and usually goes away after treatment. Maintain good oral hygiene, and brush your tongue with a soft toothbrush twice a day. Consult your doctor or pharmacist for more information.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: unusual tiredness, joint/muscle pain.

Tell your doctor immediately if any of these rare but very serious side effects occur: easy bruising/bleeding.

This medication may rarely cause a severe intestinal condition (pseudomembranous colitis) due to a type of resistant bacteria. This condition may occur during treatment or weeks to months after treatment has stopped. Do not use anti-diarrhea products or narcotic pain medications if you have any of the following symptoms because these products may make them worse. Tell your doctor immediately if you develop: persistent diarrhea, abdominal or stomach pain/cramping, blood/mucus in your stool.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge or other new symptoms.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), new fever, severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking penicillin, tell your doctor or pharmacist if you are allergic to it; or to other antibiotics including penicillin-type medications (such as amoxicillin, ampicillin) or cephalosporins (such as cephalexin, cefuroxime); or if you have any other allergies.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, older adults may be more sensitive to this drug.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: vaccines that contain live bacteria, methotrexate, tetracyclines, khat, guar gum.

Before taking penicillin, tell your doctor or pharmacist if you are also taking probenecid. Probenecid slows down the removal of penicillin from your body, resulting in higher levels of this antibiotic in your bloodstream. For certain types of difficult-to-treat infections, your doctor may prescribe these 2 medications together in order to achieve this effect. Consult your doctor or pharmacist for more details.

This medication may decrease the effectiveness of combination-type birth control pills. This can result in pregnancy. You may need to use an additional form of reliable birth control while using this medication. Consult your doctor or pharmacist for details.

Penicillin may cause false positive results with certain diabetic urine testing products (cupric sulfate-type). This drug may also affect the results of certain lab tests. Make sure laboratory personnel and your doctors know you use this drug.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe vomiting, persistent diarrhea.

NOTES: Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless told to do so by your doctor. A different medication may be necessary in that case.

With prolonged treatment, laboratory and/or medical tests (such as kidney function, complete blood counts) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store at room temperature between 59-86 degrees F (15-30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised July 2008 Copyright(c) 2008 First DataBank, Inc.