Penicillin V

Specific Drugs

Absorption

Bioavailability

Approximately 25–73% of an oral dose of penicillin V absorbed from the GI tract in healthy, fasting adults;1 2 12 47 occasional patients will not absorb therapeutic concentrations of oral penicillin.1 2

Peak serum concentrations attained within 30–60 minutes.3 11 47 48 49 50

Food

Variable results obtained in studies evaluating effect of food on GI absorption of penicillin V potassium.3 12 13 14 Food may result in lower and delayed peak serum concentrations,3 11 13 14 although the total amount of drug absorbed is unaffected.3 47 48

Distribution

Extent

Widely distributed into body tissues.1 2 Highest concentrations in kidneys;1 2 lower concentrations in liver,1 2 skin,1 2 intestines,1 2 bile,3 tonsils,51 maxillary sinus secretions,3 52 saliva,8 13 and ascitic,3 synovial,3 pleural,3 and pericardial fluids.3

Only minimal amounts in CSF.1 2 3 8

Crosses the human placenta3 and is distributed into human milk.2 15

Plasma Protein Binding

Approximately 75–89%.1 2 10 12 50 53 54

Elimination

Metabolism

Metabolized in the liver.56

Approximately 35–70% of an oral dose is metabolized to penicilloic acid which is microbiologically inactive.12 49 50 56

Elimination Route

Penicillin V and metabolites principally excreted in urine by tubular secretion.11 49

Approximately 26–65% of an oral dose excreted in urine as unchanged drug and metabolites within 6–8 hours;11 49 50 approximately 32% of the dose excreted in feces.49

Half-life

Serum half-life is 0.5 hours in adults with normal renal function.55

Special Populations

Renal clearance delayed in neonates, young infants, and individuals with renal impairment.1 2 8

• A β-lactam antibacterial classified as a natural penicillin.3 The phenoxymethyl analog of penicillin G.1 3

• Usually bactericidal.1 2

• Gram-positive aerobes: active in vitro and in clinical infections against Staphylococcus (nonpenicillinase-producing strains only),1 2 S. pneumoniae,1 2 S. pyogenes (group A β-hemolytic streptococci),1 2 and other streptococci (groups C, G, H, L, M).1 2

• Also active in vitro against Bacillus anthracis,1 2 Corynebacterium diphtheriae,1 2 and Listeria monocytogenes.1 2

• Other organisms: active in vitro against some Actinomyces bovis,1 2 Clostridium,1 2 and Streptobacillus moniliformis.1 2

• Penicillinase-producing bacteria, including penicillinase-producing S. aureus1 2 8 and S. epidermidis are resistant.1 2 Enterococci are resistant.1 2

• Advise individuals with phenylketonuria and other individuals who must restrict their intake of phenylalanine that some oral solutions contain aspartame (NutraSweet), which is metabolized in the GI tract to phenylalanine.43 44 45

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.

• Importance of women informing clinician if they are or plan to become pregnant or plan to breast-feed.

• Importance of advising patients of other important precautionary information.1 2 (See Cautions.)

Penicillin V is the phenoxymethyl analog of penicillin G.

Penicillin V potassium is the potassium salt of Penicillin V.

Molecular Formula: C16H17O5KN2S Molecular Weight: 388.5

Penicillin -VK (Penicillin V Potassium Tablets USP), for oral administration, contain 250 mg (400,000 units) or 500 mg (800,000 units) Penicillin V. In addition, each tablet contains the following inactive ingredients: hydroxypropyl methylcellulose, magnesium stearate, polyethylene glycol, povidone, talc, and titanium dioxide.

A previous hypersensitivity reaction to any penicillin is a contraindication.

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, 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-VK 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.

Occasional 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-VK should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When penicillin-VK 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-VK 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.

Penicillin-VK Tablets (Penicillin V Potassium Tablets USP), 500 mg (800,000 units) are oblong, biconvex white tablets, debossed PVK 500 on one side and GG 950 on the reverse side and break scored on both sides.

Repackaged By

Aidarex pharmaceuticals, LLC

Corona, CA 92880

Store at 20°-25°C (68°-77°F) (see USP Controlled Room Temperature).

Keep tightly closed. Dispense in a tight container, as defined in the USP.

REFERENCES

• 1.American Heart Association.1984. Prevention of bacterial endocarditis. Circulation 70(6):1123A –1127A.
• 2.Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Disk Susceptibility Test; Approved Standard-Eleventh Edition. CLSI document M02-A11. Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA, 2012.
• 3.Clinical and Laboratory Standards Institute. Methods for Dilution Antimicrobial Susceptibility Test for Bacteria That Grow Aerobically; Approved Standard-Ninth Edition. CLSI document M07-A9. Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA, 2012.
• 4.Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Twenty-Second Informational Supplement. CLSI document M100-S22. Clinical and Laboratory Standards Institute, 950 West Valley Road, Suite 2500, Wayne, Pennsylvania 19087, USA, 2012.

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