Pfizerpen
(Penicillin G Potassium)Pfizerpen Prescribing Information
Penicillin G Potassium for Injection is indicated in the treatment of serious infections caused by susceptible strains of the designated microorganisms in the conditions listed below.
Appropriate culture and susceptibility tests should be done before treatment in order to isolate and identify organisms causing infection and to determine their susceptibility to penicillin G.
Therapy with Penicillin G Potassium for Injection may be initiated before results of such tests are known when there is reason to believe the infection may involve any of the organisms listed below; however, once these results become available, appropriate therapy should be continued.
CLINICAL INDICATION | INFECTING ORGANISM | |
|---|---|---|
Septicemia, empyema, pneumonia, pericarditis, endocarditis, meningitis | Streptococcus pyogenes (group A β-hemolytic streptococcus), other β-hemolytic streptococci including groups C, H, G, L and M, Streptococcus pneumoniae and Staphylococcus species (non-penicillinase producing strains) | |
Anthrax | Bacillus anthracis | |
Actinomycosis (cervico-facial disease and thoracic and abdominal disease) | Actinomyces israelii | |
Botulism (adjunctive therapy to antitoxin), gas gangrene, and tetanus (adjunctive therapy to human tetanus immune globulin) | Clostridium species | |
Diphtheria (adjunctive therapy to antitoxin and prevention of the carrier state) | Corynebacterium diphtheriae | |
Erysipelothrix endocarditis | Erysipelothrix rhusiopathiae | |
Fusospirochetosis (severe infections of the oropharynx [Vincent's], lower respiratory tract and genital area) | Fusobacterium species and spirochetes | |
Listeria infections including meningitis and endocarditis | Listeria monocytogenes | |
Pasteurella infections including bacteremia and meningitis | Pasteurella multocida | |
Haverhill fever | Streptobacillus moniliformis | |
Rat bite fever | Spirillum minus or Streptobacillus moniliformis | |
Disseminated gonococcal infections | Neisseria gonorrhoeae (Penicillin-susceptible) | |
Syphilis (congenital and neurosyphilis) | Treponema pallidum | |
Meningococcal meningitis and/or septicemia | Neisseria meningitidis | |
Gram-negative bacillary infections (bacteremias) Penicillin G is not the drug of choice in the treatment of Gram-negative bacillary infections. | Gram-negative bacillary organisms ( i.e . Enterobacteriaceae) |
To reduce the development of drug-resistant bacteria and maintain effectiveness of Penicillin G Potassium and other antibacterial drugs, Penicillin G Potassium 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.
Buffered Penicillin G Potassium for Injection, USP may be given intravenously or intramuscularly. The usual dose recommendations are as follows:
A history of a hypersensitivity (anaphylactic) reaction to any penicillin is a contraindication.
The Jarisch-Herxheimer reaction is a systemic reaction that may occur after the initiation of penicillin therapy in patients with syphilis or other spirochetal infections (
Bacteriostatic antibacterials (
Penicillin blood levels may be prolonged by concurrent administration of probenecid which blocks the renal tubular secretion of penicillins. Other drugs may compete with penicillin G for renal tubular secretion and thus prolong the serum half-life of penicillin. These drugs include: aspirin, phenylbutazone, sulfonamides, indomethacin, thiazide diuretics, furosemide and ethacrynic acid.
Buffered Pfizerpen (Penicillin G Potassium for Injection, USP) is a sterile, pyrogen-free powder for reconstitution. Buffered Pfizerpen for Injection is an antibacterial agent for intramuscular, continuous intravenous infusion, intrapleural or other local infusion, and intrathecal administration.
Each million units contains approximately 6.8 milligrams of sodium (0.3 mEq) and 65.6 milligrams of potassium (1.68 mEq). Buffered Pfizerpen (Penicillin G Potassium for Injection, USP) is supplied in vials equivalent to 5,000,000 units (5 million units) or 20,000,000 units (20 million units) of penicillin G as the potassium salt.
Chemically, Pfizerpen is monopotassium 3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo (3.2.0) heptane-2-carboxylate. It has a molecular weight of 372.48 and the following chemical structure:
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Formula |
Penicillin G potassium is a colorless or white crystal, or a white crystalline powder which is odorless, or practically so, and moderately hygroscopic. Penicillin G potassium is very soluble in water. The pH of the reconstituted product is between 6.0–8.5.