Penicillin V potassium

Name: Penicillin V potassium

Penicillin V potassium Interactions

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or has blood in it, call your doctor. Do not use any medicine to stop the diarrhea unless your doctor has told you to.

Tell your doctor about all other medicines you use, especially:

  • birth control pills;
  • methotrexate (Rheumatrex, Trexall);
  • probenecid (Benemid); or
  • a tetracycline antibiotic, such as doxycycline (Doryx, Oracea, Periostat, Vibramycin), minocycline (Dynacin, Minocin, Solodyn, Vectrin), or tetracycline (Brodspec, Panmycin, Sumycin, Tetracap).

This list is not complete and other drugs may interact with penicillin V potassium. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

What is penicillin V potassium?

Penicillin V potassium is a slow-onset antibiotic that fights bacteria in your body.

Penicillin V potassium is used to treat many different types of infections including strep and staph infections, pneumonia, rheumatic fever, and infections affecting the mouth or throat.

Penicillin V potassium is also used to prevent infections of the heart valves in people with certain heart conditions who need to have dental work or surgery.

Penicillin V potassium may also be used for purposes not listed in this medication guide.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include some of the serious side effects listed in this medication guide.

Uses for Penicillin V Potassium

Pharyngitis and Tonsillitis

Treatment of pharyngitis and tonsillitis caused by Streptococcus pyogenes (group A β-hemolytic streptococci).5 8 30 42 57

AAP, IDSA, AHA, and others recommend oral penicillin V or IM penicillin G benzathine as treatments of choice;5 8 30 42 57 oral cephalosporins and oral macrolides are considered alternatives.5 30 42 57 Amoxicillin sometimes used instead of penicillin V, especially for young children.5 57

A second episode can be retreated with the same or other treatment of choice;5 57 other regimens (amoxicillin and clavulanate, clindamycin, penicillin G benzathine with or without rifampin) recommended for symptomatic patients with multiple, recurrent episodes.5 30 57

Consider that multiple, recurrent episodes of symptomatic pharyngitis within several months to years may be repeated episodes of nonstreptococcal (e.g., viral) pharyngitis in a streptococcal carrier;30 57 treatment not usually recommended for streptococcal pharyngeal carriers.5 30 57

Other Streptococcal Infections

Treatment of mild to moderately severe infections (without bacteremia) caused by susceptible streptococci, including upper respiratory tract infections and scarlet fever.1 2 6 8 21 Usually active against streptococci groups A, C, G, H, L, and M.1 2 8 21

Treatment of mild to moderate respiratory tract infections caused by susceptible S. pneumoniae (MIC <0.1 mcg/mL);1 2 3 6 8 however, other penicillins (penicillin G, amoxicillin, amoxicillin and clavulanate, ampicillin and sulbactam) usually recommended when a penicillin used for treatment of these infections.5 63 64

Skin or Skin Structure Infections

Treatment of mild skin or skin structure infections caused by susceptible nonpenicillinase-producing staphylococci or susceptible streptococci (e.g., erysipelas).1 2 8

Not considered a drug of choice;6 susceptibility needs to be confirmed with in vitro testing because of high incidence of penicillinase-producing staphylococci.1 2

Prevention of Rheumatic Fever Recurrence

Prevention of recurrence of rheumatic fever (secondary prophylaxis).1 2 8 30 Continuous prophylaxis recommended following treatment of documented rheumatic fever (even if manifested solely by Sydenham chorea) and in those with evidence of rheumatic heart disease.8 30

AHA recommends IM penicillin G benzathine, oral penicillin V, or oral sulfadiazine for such prophylaxis.30

Prevention of Bacterial Endocarditis

Prevention of bacterial endocarditis in patients with congenital heart disease or rheumatic or other acquired valvular heart disease undergoing certain dental or upper respiratory tract procedures.1

Not a drug of choice; AHA recommends amoxicillin for prevention of bacterial endocarditis in high- or moderate-risk patients undergoing certain dental, oral, respiratory tract, or esophageal procedures.65

Consult most recent AHA recommendations for specific information on which cardiac conditions are associated with high or moderate risk of endocarditis and which procedures require prophylaxis.65

Prevention of S. pneumoniae Infections in Asplenic Individuals

Prevention of S. pneumoniae infections in children with anatomic or functional asplenia† (e.g., congenital, as the result of sickle cell disease or splenectomy),4 5 8 58 59 62 children with malignant neoplasms or thalassemia,5 8 and asplenic adults (e.g., after splenectomy for trauma).24 62

Usually drug of choice for prophylaxis in asplenic children;5 60 62 some experts recommend amoxicillin.5

Children at increased risk for pneumococcal infections should receive pneumococcal 7-valent conjugate vaccine and pneumococcal 23-valent polysaccharide vaccine.5 60 61 62 Long-term anti-infective prophylaxis recommended for children with anatomic or functional asplenia regardless of vaccination status.5 60 61 62

Necrotizing Ulcerative Gingivitis

Treatment of mild to moderate acute necrotizing ulcerative gingivitis and pharyngitis (Vincent’s infection, trench mouth, Fusobacterium gingivitis or pharyngitis).1 2

Anthrax

An alternative for postexposure prophylaxis of anthrax† following exposure to Bacillus anthracis spores (inhalational anthrax).33 Ciprofloxacin or doxycycline are initial drugs of choice for postexposure prophylaxis following suspected or confirmed bioterrorism-related anthrax exposure.33 36 37 38 39 41 If penicillin susceptibility is confirmed, consideration can be given to changing prophylaxis to a penicillin in infants and children and in pregnant or lactating women;33 36 amoxicillin usually is recommended.36 37 39

Treatment of mild, uncomplicated cutaneous anthrax† caused by susceptible B. anthracis that occurs as the result of naturally occurring or endemic exposure to anthrax.34 36 If cutaneous anthrax occurs in the context of biologic warfare or bioterrorism, initial drugs of choice are ciprofloxacin or doxycycline.36 38 41 If penicillin susceptibility is confirmed, consideration can be given to changing to a penicillin in infants and children or in pregnant or lactating women; amoxicillin usually is recommended.36 38

Actinomycosis

Follow-up treatment of actinomycosis† after initial treatment with parenteral penicillin G or ampicillin.5 8 20 22 32

Treatment of mild cervicofacial actinomycosis.32

Rat-bite Fever

Follow-up treatment of rat-bite fever† caused by Streptobacillus moniliformis in afebrile patients who respond to initial treatment with parenteral penicillin G.5

Whipple’s Disease

Follow-up treatment of Whipple’s disease† after initial therapy with parenteral penicillin G.3 8

Indications and Usage for Penicillin V Potassium

Penicillin V Potassium Tablets, USP are indicated in the treatment of mild to moderately severe infections due to penicillin G-sensitive microorganisms. Therapy should be guided by bacteriological studies (including sensitivity 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 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.

NOTE: 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.

NOTE: 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 tract1. 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.

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 Association1.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Penicillin V Potassium Tablets, USP and other antibacterial drugs, Penicillin V Potassium Tablets, USP 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.

Contraindications

A previous hypersensitivity reaction to any penicillin is a contraindication.

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 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 V Potassium Dosage and Administration

The dosage of Penicillin V Potassium tablets 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 to 250 mg (200,000 to 400,000 units) twice daily on a continuing basis.

For prophylaxis against bacterial endocarditis1 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.

Pharmacologic Category

  • Antibiotic, Penicillin

Warnings/Precautions

Concerns related to adverse effects:

• Anaphylactic/hypersensitivity reactions: Serious and occasionally severe or fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy, especially with a history of beta-lactam hypersensitivity or history of sensitivity to multiple allergens.). Use with caution in asthmatic patients. If a serious reaction occurs, treatment with supportive care measures and airway protection should be instituted immediately.

• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.

Disease-related concerns:

• Renal impairment: Use with caution in patients with severe renal impairment.

• Seizure disorders: Use with caution in patients with a history of seizure disorder; high levels, particularly in the presence of renal impairment, may increase risk of seizures.

Concurrent drug therapy related issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC, 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer’s labeling.

Other warnings/precautions:

• Prolonged use: Extended duration of therapy or use associated with high serum concentrations (eg, in renal insufficiency) may be associated with an increased risk for some adverse reactions (neutropenia, hemolytic anemia, serum sickness).

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