Aqueous penicillin G (parenteral) is indicated in the therapy of severe infections caused by penicillin G-susceptible microorganisms when rapid and high penicillin levels are required in the conditions listed below.
Therapy should be guided by bacteriological studies (including susceptibility tests) and by clinical response.The following infections will usually respond to adequate dosage of aqueous penicillin G (parenteral):Streptococcal infections.NOTE: Streptococci in groups A, C, H, G, L, and M are very sensitive to penicillin G.
Some group D organisms are sensitive to the high serum levels obtained with aqueous penicillin G.Aqueous penicillin G (parenteral) is the penicillin dosage form of choice for bacteremia, empyema, severe pneumonia, pericarditis, endocarditis, meningitis, and other severe infections caused by sensitive strains of the gram-positive species listed above.Pneumococcal infections.Staphylococcal infections–penicillin G sensitive.Other infections:Anthrax.Actinomycosis.Clostridial infections (including tetanus).Diphtheria (to prevent carrier state).Erysipeloid (Erysipelothrix insidiosa) endocarditis.Fusospirochetal infections–severe infections of the oropharynx (Vincent's), lower respiratory tract and genital area due to Fusobacterium fusiformisans spirochetes.Gram-negative bacillary infections (bacteremias)–(E.
faecalis, Salmonella, Shigella and P.
mirabilis).Listeria infections (Listeria monocytogenes).Meningitis and endocarditis.Pasteurella infections (Pasteurella multocida).Bacteremia and meningitis.Rat-bite fever (Spirillum minus or Streptobacillus moniliformis).Gonorrheal endocarditis and arthritis (N.
pallidum) including congenital syphilis.Meningococcic meningitis.Although no controlled clinical efficacy studies have been conducted, aqueous crystalline penicillin G for injection and penicillin G procaine suspension have been suggested by the American Heart Association and the American Dental Association for use as part of a combined parenteral-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 upper respiratory tract.1 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 Association.1To reduce the development of drug-resistant bacteria and maintain effectiveness of Pfizerpen and other antibacterial drugs, Pfizerpen 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.
Serious and occasionally fatal hypersensitivity (anaphylactoid) 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 any penicillin, careful inquiry should be made concerning previous hypersensitivity reactions to penicillin, cephalosporins, or other allergens.
If an allergic reaction occurs, the drug should be discontinued and the appropriate therapy instituted.
Serious anaphylactoid reactions require immediate emergency treatment with epinephrine.Oxygen, intravenous steroids, and airway management including intubation, should also be administered as indicated.