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Penicillin V

Class: Natural Penicillins
VA Class: AM110
Chemical Name: [2S-(2α,5α,6β)]-3,3-Dimethyl-7-oxo-6-[(phenoxyacetyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid monopotassium salt
CAS Number: 132-98-9

Medically reviewed by Drugs.com on Aug 31, 2021. Written by ASHP.

Introduction

Antibacterial; β-lactam antibiotic; natural penicillin.

Uses for Penicillin V

Pharyngitis and Tonsillitis

Treatment of pharyngitis and tonsillitis caused by susceptible Streptococcus pyogenes (group A β-hemolytic streptococci; GAS) and prevention of initial attacks (primary prevention) of rheumatic fever.

AAP, IDSA, and AHA recommend a penicillin regimen (i.e., 10 days of oral penicillin V or oral amoxicillin or single dose of IM penicillin G benzathine) as treatment of choice for S. pyogenes pharyngitis and tonsillitis; other anti-infectives (narrow-spectrum oral cephalosporins, oral macrolides, oral clindamycin) recommended as alternatives in penicillin-allergic patients.

If signs and symptoms of pharyngitis recur shortly after initial treatment and presence of S. pyogenes documented, retreatment with original or alternative anti-infective recommended. Alternative regimens recommended for retreatment include a narrow-spectrum oral cephalosporin, oral clindamycin, oral fixed combination of amoxicillin and clavulanate, oral macrolide, or IM penicillin G benzathine.

Consider that multiple, recurrent episodes of symptomatic pharyngitis within a period of several months to years may indicate the patient is a long-term pharyngeal carrier of S. pyogenes experiencing repeated episodes of nonstreptococcal (e.g., viral) pharyngitis.

Treatment not usually recommended for asymptomatic chronic pharyngeal carriers of S. pyogenes. Eradication of the carrier state may be desirable in certain situations (e.g., community outbreak of acute rheumatic fever, acute poststreptococcal glomerulonephritis, or invasive S. pyogenes infections; outbreak of S. pyogenes pharyngitis in a closed or partially closed community; multiple episodes of documented symptomatic S. pyogenes pharyngitis occurring within a family for many weeks despite appropriate treatment; personal or family history of acute rheumatic fever). In such situations, recommended regimens include oral clindamycin, oral fixed combination of amoxicillin and clavulanate, or oral rifampin used in conjunction with either IM penicillin G benzathine or oral penicillin V.

Streptococcal Infections

Treatment of mild to moderate infections (without bacteremia) caused by susceptible streptococci. Usually active against S. pyogenes (group A β-hemolytic streptococci; GAS) and streptococci groups C, G, H, L, and M.

Respiratory Tract Infections

Treatment of mild community-acquired pneumoniae (CAP) caused by susceptible S. pyogenes or for step-down treatment of CAP caused by S. pyogenes after an initial parenteral regimen.

Treatment of mild to moderately severe respiratory tract infections caused by susceptible S. pneumoniae or other susceptible streptococci. Consider that other penicillins (penicillin G, amoxicillin, fixed combination of amoxicillin and clavulanate, ampicillin, fixed combination of ampicillin and sulbactam) usually recommended when a penicillin used for treatment of respiratory tract infections.

Consult current IDSA clinical practice guidelines available at [Web] for additional information on treatment of CAP.

Skin or Skin Structure Infections

Treatment of mild skin or skin structure infections caused by susceptible streptococci (e.g., nonpurulent cellulitis, erysipelas).

Treatment of mild skin or skin structure infections caused by susceptible non-penicillinase-producing staphylococci. Because of high incidence of penicillinase-producing staphylococci, confirm susceptibility with in vitro testing.

Consult current IDSA clinical practice guidelines available at [Web] for additional information on treatment of skin and skin structure infections.

Necrotizing Ulcerative Gingivitis

Has been used for treatment of mild to moderate infections of the oropharynx caused by Fusobacterium, including acute necrotizing ulcerative gingivitis (Vincent’s infection, trench mouth, Fusobacterium gingivitis or pharyngitis).

Prevention of Rheumatic Fever Recurrence

Alternative for prevention of recurrent attacks of rheumatic fever (secondary prophylaxis) in individuals who have had a previous attack of rheumatic fever.

IM penicillin G benzathine generally considered drug of choice for secondary prophylaxis of rheumatic fever because it ensures compliance; alternatives include oral penicillin V or oral sulfadiazine.

AHA and AAP recommend long-term (continuous) secondary prophylaxis following treatment of documented acute rheumatic fever (even if manifested solely by Sydenham chorea) and in those with evidence of rheumatic heart disease (even after prosthetic valve replacement).

Initiate prophylaxis as soon as rheumatic fever or rheumatic heart disease diagnosed, although patients with acute rheumatic fever should first receive usually recommended anti-infective treatment for S. pyogenes pharyngitis and tonsillitis (see Pharyngitis and Tonsillitis under Uses).

Prevention of Invasive Pneumococcal Disease in Asplenic Individuals

Prevention of invasive S. pneumoniae disease in children with anatomic or functional asplenia (e.g., congenital asplenia or polysplenia, splenectomy, sickle cell disease, thalassemia). AAP recommends such prophylaxis be continued until at least 5 years of age in those with sickle cell disease and for at least 1 year after splenectomy in all age groups.

Prevention of invasive S. pneumoniae disease in certain asplenic adults; some clinicians recommend that such prophylaxis be continued for at least 1–2 years after splenectomy in adults.

Asplenic infants, children, adolescents, and adults are at increased risk of fulminant septicemia, most commonly caused by S. pneumoniae. Age-appropriate vaccination against pneumococcal disease with pneumococcal 13-valent conjugate vaccine (PCV13) and pneumococcal 23-valent polysaccharide vaccine (PPSV23) recommended in all asplenic individuals. Anti-infective prophylaxis recommended by AAP for young children with anatomic or functional asplenia, regardless of vaccination status.

Penicillin V usually considered drug of choice for prophylaxis of pneumococcal disease in asplenic children; some experts recommend amoxicillin.

Prevention of Bacterial Endocarditis

Has been recommended in the past for prevention of bacterial endocarditis in patients with certain cardiac risk factors undergoing certain dental or upper respiratory tract procedures.

Not included in current AHA guidelines for prevention of bacterial endocarditis; oral amoxicillin is drug of choice when prevention of bacterial endocarditis indicated in patients with certain cardiac conditions undergoing certain dental or upper respiratory tract procedures.

Consult most recent AHA recommendations for specific information on which cardiac conditions are associated with highest risk of adverse outcomes from endocarditis and specific recommendations regarding use of prophylaxis to prevent endocarditis in these patients.

Anthrax

Alternative for postexposure prophylaxis of anthrax following exposure to Bacillus anthracis spores (inhalational anthrax). Ciprofloxacin or doxycycline are initial drugs of choice for prophylaxis following suspected or confirmed exposure to aerosolized anthrax spores, including exposures that occur in the context of biologic warfare or bioterrorism. If penicillin susceptibility confirmed, consideration can be given to changing prophylaxis to a penicillin (oral amoxicillin or penicillin V) in infants and children, pregnant or lactating women, or when drugs of choice not tolerated or not available; oral amoxicillin may be preferred, especially in infants and children.

Treatment of mild, uncomplicated cutaneous anthrax caused by susceptible B. anthracis that occurs as the result of naturally occurring or endemic exposure to anthrax. If cutaneous anthrax occurs in the context of biologic warfare or bioterrorism, initial drugs of choice are ciprofloxacin or doxycycline. If penicillin susceptibility confirmed, consideration can be given to changing treatment to a penicillin (oral amoxicillin or penicillin V) in infants and children, pregnant or lactating women, or when drugs of choice not tolerated or not available; oral amoxicillin may be preferred, especially in infants and children.

Actinomycosis

Treatment of actinomycosis after initial response obtained with IV penicillin G or ampicillin.

Treatment of mild cervicofacial actinomycosis; oral amoxicillin may be preferred.

Rat-bite Fever

Has been used for treatment of rat-bite fever caused by susceptible Streptobacillus moniliformis in patients who responded to initial treatment with IV penicillin G.

Penicillin V Dosage and Administration

Administration

Oral Administration

Administer orally.

Although manufacturers state oral penicillin V may be given with meals, administration in fasting state (preferably 1 hour before meals) generally recommended. Maximum oral absorption achieved when given at least 1 hour before or 2 hours after meals.

Do not use for initial treatment of severe infections. Should not be relied on in patients with nausea, vomiting, gastric dilatation, cardiospasm, or intestinal hypermotility.

Reconstitution

Reconstitute powder for oral solution at time of dispensing by adding the amount of water specified on the bottle to provide a solution containing 125 or 250 mg of penicillin V per 5 mL. Add the water in 2 portions; shake vigorously after each addition.

Dosage

Available as the potassium salt. Dosage usually expressed as mg of penicillin V, but may be expressed in terms of penicillin V units.

Potency of penicillin V potassium preparations containing 125, 250, or 500 mg of penicillin V is approximately equivalent to 200,000, 400,000, or 800,000 penicillin V units, respectively.

Pediatric Patients

General Dosage in Children Beyond the Neonatal Period
Mild to Moderate Infections
Oral

AAP recommends 25–75 mg/kg daily given in 3 or 4 divided doses.

Some clinicians recommend 125 mg 4 times daily in children <5 years of age and 250–500 mg every 6 hours in those >5 years of age.

Manufacturers state pediatric patients ≥12 years of age may receive usual adult dosage; some clinicians state that those >5 years of age may receive usual adult dosage.

Pharyngitis and Tonsillitis
Oral

Children: 250 mg 2 or 3 times daily for 10 days recommended by AAP, AHA, and IDSA. Some experts recommend 500 mg 2 or 3 times daily in those weighing >27 kg.

Adolescents: 500 mg 2 or 3 times daily for 10 days or 250 mg 4 times daily for 10 days.

Eradication of chronic pharyngeal carriage of S. pyogenes in certain circumstances (see Pharyngitis and Tonsillitis under Uses): IDSA states 50 mg/kg daily (up to 2 g daily) in 4 divided doses for 10 days in conjunction with oral rifampin (20 mg/kg daily as a single dose [up to 600 mg daily] given during last 4 days of penicillin V treatment) is an option.

Respiratory Tract Infections
Oral

Children ≥3 months of age: 50–75 mg/kg daily in 3 or 4 divided doses recommended for treatment of mild CAP caused by S. pyogenes or as step-down after initial parenteral treatment.

Adolescents ≥12 years of age: 125–250 mg every 6–8 hours for 10 days recommended by manufacturers for treatment of mild to moderate infections (including scarlet fever) caused by susceptible streptococci.

Adolescents ≥12 years of age: 250–500 mg every 6 hours recommended by manufacturers for treatment of mild to moderately severe infections (including otitis media) caused by susceptible S. pneumoniae; continue until afebrile for at least 2 days.

Skin and Skin Structure Infections
Oral

Adolescents ≥12 years of age: 125–250 mg every 6–8 hours for 10 days recommended by manufacturers for treatment of mild to moderate erysipelas caused by susceptible streptococci.

Adolescents ≥12 years of age: 250–500 mg every 6–8 hours recommended by manufacturers for mild infections caused by susceptible non-penicillinase-producing staphylococci. Because of high incidence of resistant strains, perform in vitro culture and susceptibility testing when treating suspected staphylococcal infections.

Necrotizing Ulcerative Gingivitis
Oral

Adolescents ≥12 years of age: 250–500 mg every 6–8 hours for mild to moderate infections.

Prevention of Rheumatic Fever Recurrence
Oral

Children: AAP and AHA recommend 250 mg twice daily.

Adolescents ≥12 years of age: Manufacturers recommend 125–250 mg twice daily.

Long-term, continuous prophylaxis required. (See Table 1.) Some clinicians use IM penicillin G benzathine initially and change to oral prophylaxis (usually penicillin V) when patient reaches late adolescence or young adulthood and has remained free of rheumatic attacks for ≥5 years.

Table 1. Recommended Duration of Prophylaxis for Prevention of Rheumatic Fever Recurrence292375

Patient Category

Duration

Rheumatic fever without carditis

5 years since last episode or until 21 years of age, whichever is longer

Rheumatic fever with carditis but no residual heart disease (no valvular disease)

10 years since last episode or until 21 years of age, whichever is longer

Rheumatic fever with carditis and residual heart disease (persistent valvular disease)

10 years since last episode or until 40 years of age, whichever is longer; sometimes for life

Prevention of Invasive Pneumococcal Disease in Asplenic Individuals†
Oral

Children <3 years of age: 125 mg twice daily recommended by AAP.

Children ≥3 years of age: 250 mg twice daily recommended by AAP.

Infants with sickle cell anemia: Initiate prophylaxis as soon as diagnosis established (preferably by 2 months of age). AAP states discontinuance of prophylaxis may be considered at 5 years of age if child receives regular medical attention, is fully immunized against pneumococcal disease, and has not had a severe pneumococcal infection or surgical splenectomy.

Children with asplenia from causes other than sickle cell anemia: Appropriate duration of prophylaxis unknown; some experts recommend such children receive prophylaxis throughout childhood and into adulthood. AAP recommends continuing prophylaxis for at least 1 year after splenectomy.

Anthrax†
Postexposure Prophylaxis of Anthrax†
Oral

Full-term neonates exposed to aerosolized B. anthracis spores in the context of biologic warfare or bioterrorism: AAP recommends 75 mg/kg daily given in divided doses every 6–8 hours in those ≤1 week of age and 75 mg/kg daily given in divided doses every 8 hours in those 1–4 weeks of age.

Preterm neonates (gestational age 32–37 weeks) exposed to aerosolized B. anthracis spores in the context of biologic warfare or bioterrorism: AAP recommends 50 mg/kg daily given in divided doses every 12 hours in those ≤1 week of age and 75 mg/kg daily given in divided doses every 8 hours in those 1–4 weeks of age.

Infants and children ≥1 month of age exposed to aerosolized B. anthracis spores in the context of biologic warfare or bioterrorism: AAP recommends 50–75 mg/kg daily given in divided doses every 6–8 hours.

Use only if penicillin-susceptible B. anthracis involved.

Total duration of anti-infective prophylaxis should be ≥60 days.

Treatment of Cutaneous Anthrax†
Oral

Full-term neonates with cutaneous anthrax without systemic involvement that occurred in the context of biologic warfare or bioterrorism: AAP recommends 75 mg/kg daily given in divided doses every 6–8 hours in those ≤1 week of age and 75 mg/kg daily given in divided doses every 8 hours in those 1–4 weeks of age.

Preterm neonates (gestational age 32–37 weeks) with cutaneous anthrax without systemic involvement that occurred in the context of biologic warfare or bioterrorism: AAP recommends 50 mg/kg daily given in divided doses every 12 hours in those ≤1 week of age and 75 mg/kg daily given in divided doses every 8 hours in those 1–4 weeks of age.

Infants and children ≥1 month of age with cutaneous anthrax without systemic involvement that occurred in the context of biologic warfare or bioterrorism: AAP recommends 50–75 mg/kg daily given in divided doses every 6–8 hours.

Children with mild, uncomplicated cutaneous anthrax resulting from naturally occurring or endemic exposure: 25–50 mg/kg daily given in 2 or 4 divided doses.

Use only if infection known to be caused by penicillin-susceptible B. anthracis.

Although 3–10 days of treatment may be adequate if cutaneous anthrax occurred as the result of natural or endemic exposures, some experts recommend duration of 7–14 days. CDC, AAP, and others recommend 60 days of anti-infective treatment if cutaneous anthrax occurred as the result of exposure to aerosolized anthrax spores (e.g., in context of biologic warfare or bioterrorism).

Rat-bite Fever
Oral

Children: 25–50 mg/kg daily (up to 3 g daily) given in 4 divided doses after initial treatment with IV penicillin G.

Adults

Pharyngitis and Tonsillitis
Oral

500 mg 2 or 3 times daily for 10 days or 250 mg 4 times daily for 10 days.

Eradication of chronic pharyngeal carriage of S. pyogenes in certain circumstances (see Pharyngitis and Tonsillitis under Uses): IDSA states 50 mg/kg daily (up to 2 g daily) in 4 divided doses for 10 days in conjunction with oral rifampin (20 mg/kg daily as a single dose [up to 600 mg daily] given during last 4 days of penicillin V treatment) is an option.

Respiratory Tract Infections
Oral

125–250 mg every 6–8 hours for 10 days recommended by manufacturers for mild to moderately severe infections (including scarlet fever) caused by susceptible streptococci.

250–500 mg every 6 hours recommended by manufacturers for mild to moderately severe infections (including otitis media) caused by susceptible S. pneumoniae; continue until afebrile for at least 2 days.

Skin and Skin Structure Infections
Oral

125–250 mg every 6–8 hours for 10 days recommended by manufacturers for mild to moderate erysipelas caused by susceptible streptococci.

250–500 mg every 6–8 hours recommended by IDSA for nonpurulent skin and skin structure infections (e.g., cellulitis) caused by susceptible streptococci.

250–500 mg every 6–8 hours recommended by manufacturers for mild infections caused by susceptible non-penicillinase-producing staphylococci. Because of high incidence of resistant strains, perform in vitro culture and susceptibility testing when treating suspected staphylococcal infections.

Necrotizing Ulcerative Gingivitis
Oral

250–500 mg every 6–8 hours for mild to moderate infections.

Prevention of Rheumatic Fever Recurrence
Oral

AHA recommends 250 mg twice daily.

Manufacturers recommend 125–250 mg twice daily.

Long-term, continuous prophylaxis required. (See Table 2.)

Table 2. Recommended Duration of Prophylaxis for Prevention of Rheumatic Fever Recurrence292375

Patient Category

Duration

Rheumatic fever without carditis

5 years since last episode or until 21 years of age, whichever is longer

Rheumatic fever with carditis but no residual heart disease (no valvular disease)

10 years since last episode or until 21 years of age, whichever is longer

Rheumatic fever with carditis and residual heart disease (persistent valvular disease)

10 years since last episode or until 40 years of age, whichever is longer; sometimes for life

Anthrax†
Postexposure Prophylaxis of Anthrax†
Oral

500 mg every 6 hours in adults (including pregnant and postpartum women) exposed to aerosolized B. anthracis spores in the context of biologic warfare or bioterrorism.

Use only if penicillin-susceptible B. anthracis involved.

Total duration of anti-infective prophylaxis should be ≥60 days.

Treatment of Cutaneous Anthrax†
Oral

Mild, uncomplicated cutaneous anthrax resulting from naturally occurring or endemic exposure: 500 mg 4 times daily; some clinicians recommend 200–500 mg 4 times daily.

Cutaneous anthrax without systemic involvement that occurred in the context of biologic warfare or bioterrorism: 500 mg 4 times daily in adults (including pregnant and postpartum women).

Use only if infection known to be caused by penicillin-susceptible B. anthracis.

Although 3–10 days of treatment may be adequate if cutaneous anthrax occurred as the result of natural or endemic exposures, some experts recommend duration of 7–14 days. CDC and others recommend 60 days of anti-infective treatment if cutaneous anthrax occurred as the result of exposure to aerosolized anthrax spores (e.g., in context of biologic warfare or bioterrorism).

Actinomycosis†
Oral

2–4 g daily given in divided doses every 6 hours for 6–12 months after initial 2–6 weeks of treatment with IV penicillin G.

Mild cervicofacial actinomycosis: 2-month regimen of penicillin V may be adequate.

Rat-bite Fever†
Oral

500 mg every 6 hours recommended after initial response obtained with IV penicillin G.

Special Populations

Renal Impairment

Dosage adjustments not usually needed.

Clcr <10 mL/minute: Some clinicians suggest increasing dosing interval to every 8 hours.

Cautions for Penicillin V

Contraindications

  • Known hypersensitivity to any penicillin.

Warnings/Precautions

Warnings

Superinfection/Clostridium difficile-associated Diarrhea and Colitis

Possible emergence and overgrowth of nonsusceptible organisms, including fungi. Institute appropriate therapy if superinfection occurs.

Treatment with anti-infectives alters normal colon flora and may permit overgrowth of Clostridium difficile. C. difficile infection (CDI) and C. difficile-associated diarrhea and colitis (CDAD; also known as antibiotic-associated diarrhea and colitis or pseudomembranous colitis) reported with nearly all anti-infectives, including penicillin V, and may range in severity from mild diarrhea to fatal colitis. C. difficile produces toxins A and B which contribute to development of CDAD; hypertoxin-producing strains of C. difficile are associated with increased morbidity and mortality since they may be refractory to anti-infectives and colectomy may be required.

Consider CDAD if diarrhea develops during or after therapy and manage accordingly. Obtain careful medical history since CDAD may occur as late as ≥2 months after anti-infective therapy discontinued.

If CDAD suspected or confirmed, discontinue anti-infectives not directed against C. difficile as soon as possible. Initiate appropriate anti-infective therapy directed against C. difficile (e.g., vancomycin, fidaxomicin, metronidazole), appropriate supportive therapy (e.g., fluid and electrolyte management, protein supplementation), and surgical evaluation as clinically indicated.

Sensitivity Reactions

Hypersensitivity Reactions

Serious and occasionally fatal hypersensitivity reactions, including anaphylaxis, reported with penicillins.

Rash (maculopapular), exfoliative dermatitis, urticaria and other serum sickness-like reactions, laryngeal edema, and anaphylaxis reported with oral penicillins. Fever and eosinophilia may frequently be the only reaction observed.

Prior to initiation of therapy, make careful inquiry concerning previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens. Partial cross-allergenicity occurs among penicillins and other β-lactam antibiotics, including cephalosporins and cephamycins.

Hypersensitivity reactions more likely to occur in individuals with history of penicillin hypersensitivity and/or history of sensitivity to multiple allergens. Use with caution in individuals with history of clinically important allergies and/or asthma.

If hypersensitivity reaction occurs, discontinue immediately and institute appropriate therapy as indicated (e.g., epinephrine, corticosteroids, maintenance of an adequate airway and oxygen).

General Precautions

Severe Infections

Use only for mild to moderate infections caused by susceptible bacteria.

Do not use for initial treatment of severe infections, including pneumonia, empyema, bacteremia, pericarditis, meningitis, or arthritis.

Phenylketonuria

Some penicillin V oral solutions contain aspartame, which is metabolized in the GI tract to phenylalanine. These oral solutions containing 125 or 250 mg of penicillin V per 5 mL contain 4.5 mg of phenylalanine per 5 mL.

Consider the aspartame content in individuals with phenylketonuria (i.e., homozygous genetic deficiency of phenylalanine hydroxylase) and others who must restrict their intake of phenylalanine.

Selection and Use of Anti-infectives

To reduce development of drug-resistant bacteria and maintain effectiveness of penicillin V and other antibacterials, use only for treatment or prevention of infections proven or strongly suspected to be caused by susceptible bacteria.

When selecting or modifying anti-infective therapy, use results of culture and in vitro susceptibility testing. In the absence of such data, consider local epidemiology and susceptibility patterns when selecting anti-infectives for empiric therapy.

Specific Populations

Pregnancy

Available data regarding use of penicillin V in pregnant women, including first-trimester exposures, have not revealed evidence of an association between the drug and congenital defects.

Some clinicians state penicillin V considered low risk and safe for use during pregnancy.

Lactation

Distributed into milk. Some clinicians state penicillin V usually considered compatible with breast-feeding; others state use with caution in nursing women.

Pediatric Use

Renal clearance of penicillin V is delayed in neonates and young infants.

Renal Impairment

Substantially eliminated by kidneys; renal clearance delayed in renal impairment.

Common Adverse Effects

Adverse GI effects (e.g., nausea, vomiting, epigastric distress, diarrhea, black hairy tongue), hypersensitivity reactions (e.g., fever, eosinophilia, rash, urticaria, serum sickness-like reactions).

Penicillin V Pharmacokinetics

Absorption

Bioavailability

Approximately 60–73% of an oral dose of penicillin V (no longer commercially available in US) or penicillin V potassium is absorbed from GI tract in healthy, fasting adults. Considerable interindividual variation in extent of oral absorption; some patients may not absorb therapeutic concentrations of oral penicillins.

Peak serum concentrations attained within 30–60 minutes.

Food

Variable results obtained in studies evaluating effect of food on GI absorption of penicillin V potassium. Food may result in lower and delayed peak serum concentrations.

If administered 1 hour before a meal, peak serum concentrations may be threefold higher and total amount absorbed may be twofold higher compared with administration with food.

Distribution

Extent

Widely distributed into body tissues. Highest concentrations in kidneys; also distributed into liver, skin, intestines, bile, tonsils, maxillary sinus secretions, saliva, and ascitic, synovial, pleural, and pericardial fluids.

Only minimal amounts distributed into CSF.

Crosses human placenta.

Distributed into human milk.

Plasma Protein Binding

Approximately 75–89%.

Elimination

Metabolism

Metabolized in the liver.

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

Elimination Route

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

Approximately 20–65% of an oral dose excreted in urine as unchanged drug and metabolites within 6–8 hours; small amounts excreted in feces and bile.

Half-life

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

Special Populations

Neonates and young infants: Delayed renal clearance.

Renal impairment: Delayed renal clearance.

Pregnant women: Increased renal clearance during second and third trimesters.

Stability

Storage

Oral

Tablets

20–25°C. Keep container tightly closed; protect from moisture.

For Solution

20–25°C. Keep container tightly closed; protect from moisture.

Following reconstitution, refrigerate and discard after 14 days.

Actions and Spectrum

  • Penicillin V is a β-lactam antibacterial classified as a natural penicillin. The phenoxymethyl analog of penicillin G.

  • Like other β-lactam antibiotics, antibacterial activity results from inhibition of bacterial cell wall synthesis. Usually bactericidal.

  • Spectrum of activity similar to that of penicillin G, but penicillin V is less potent than penicillin G against susceptible bacteria.

  • Gram-positive aerobes: Active in vitro and in clinical infections against Staphylococcus (non-penicillinase-producing strains only), Streptococcus pneumoniae, S. pyogenes (group A β-hemolytic streptococci; GAS), viridans streptococci, and other streptococci (groups C, G, H, L, M).

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

  • Other organisms: Active in vitro against some Actinomyces, Clostridium (C. perfringens, C. tetani), Leptospira, and Streptobacillus moniliformis.

  • Penicillinase-producing bacteria, including penicillinase-producing staphylococci are resistant. Enterococci are resistant.

Advice to Patients

  • Advise patients that antibacterials (including penicillin V) should only be used to treat bacterial infections and not used to treat viral infections (e.g., the common cold).

  • Importance of completing full course of therapy, even if feeling better after a few days.

  • Advise patients that skipping doses or not completing the full course of therapy may decrease effectiveness and increase the likelihood that bacteria will develop resistance and will not be treatable with penicillin V or other antibacterials in the future.

  • Advise patients that diarrhea is a common problem caused by anti-infectives and usually ends when the drug is discontinued. Importance of contacting a clinician if watery and bloody stools (with or without stomach cramps and fever) occur during or as late as 2 months or longer after last dose.

  • Advise individuals with phenylketonuria and other individuals who must restrict their intake of phenylalanine that some penicillin V oral solutions contain aspartame, which is metabolized in the GI tract to phenylalanine.

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

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

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

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Penicillin V Potassium

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

For solution

125 mg (of penicillin V) per 5 mL*

Penicillin V Potassium for Oral Solution

250 mg (of penicillin V) per 5 mL*

Penicillin V Potassium for Oral Solution

Tablets

250 mg (of penicillin V)*

Penicillin V Potassium Tablets

500 mg (of penicillin V)*

Penicillin V Potassium Tablets

Tablets, film-coated

250 mg (of penicillin V)*

Penicillin V Potassium Tablets

500 mg (of penicillin V)*

Penicillin V Potassium Tablets

AHFS DI Essentials™. © Copyright 2022, Selected Revisions September 10, 2018. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

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