DOSAGE AND ADMINISTRATION
Severe infections due to Susceptible Strains of Streptococci, Pneumococci,
and Staphylococci-bacteremia, pneumonia, endocarditis, pericarditis,
empyema, meningitis, and other severe infections-a minimum of 5 million units
daily.
Syphilis - Aqueous penicillin G may be used in the treatment of acquired and
congenital syphilis, but because of the necessity of frequent dosage, hospitalization
is recommended. Dosage and duration of therapy will be determined by age of
patient and stage of the disease.
Gonorrheal endocarditis - a minimum of 5 million units daily.
Meningococcic meningitis - 1-2 million units intramuscularly every 2 hours,
or continuous IV drip of 20-30 million units/day.
Actinomycosis - 1-6 million units/day for cervicofacial cases; 10-20 million
units/day for thoracic and abdominal disease.
Clostridial infections - 20 million units/day; penicillin is adjunctive therapy
to antitoxin.
Fusospirochetal infections - severe infections of oropharynx, lower respiratory
tract, and genital area-5-10 million units/day.
Rat-bite fever (Spirillum minus or Streptobacillus moniliformis) - 12-15 million
units/day for 3-4 weeks.
Listeria infections (Listeria monocytogenes)
Neonates - 500,000 to 1 million units/day
Adults with meningitis - 15-20 million units/day for 2 weeks.
Adults with endocarditis - 15-20 million units/day for 4 weeks.
Pasteurella infections (Pasteurella multocida)
Bacteremia and meningitis - 4-6 million units/day for 2 weeks.
Erysipeloid (Erysipelothrix insidiosa)
Endocarditis - 2-20 million units/day for 4-6 weeks.
Gram-negative bacillary infections (E. coli, Enterobacter aerogenes, A. faecalis,
Salmonella, Shigella and Proteus mirabilis)
Bacteremia - 20-80 million units/day.
Diphtheria (carrier state) - 300,000-400,000 units of penicillin/day in divided
doses for 10-12 days.
Anthrax - A minimum of 5 million units of penicillin/day in divided doses until
cure is effected.
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, use a combined parenteral-oral regimen. One million units of aqueous
crystalline penicillin G (30,000 units/kg in children) intramuscularly, mixed
with 600,000 units procaine penicillin G (600,000 units for children) should
be given one-half to one hour before the procedure. Oral penicillin V (phenoxymethyl
penicillin), 500 mg for adults or 250 mg for children less than 60 lb, should
be given every 6 hours for 8 doses. Doses for children should not exceed recommendations
for adults for a single dose or for a 24 hour period.
Reconstitution
The following table shows the amount of solvent required for solution of various
concentrations:
Approx. Desired
Concentration
(units/mL) |
Approx. Volume (mL)
1,000,000
units |
Solvent for Vial of
5,000,000
units |
Infusion Only
20,000,000
units |
50,000 |
20.0 |
- |
- |
100,000 |
10.0 |
- |
- |
250,000 |
4.0 |
18.2 |
75.0 |
500,000 |
1.8 |
8.2 |
33.0 |
750,000 |
- |
4.8 |
- |
1,000,000 |
- |
3.2 |
11.5 |
When the required volume of solvent is greater than the capacity of the vial,
the penicillin can be dissolved by first injecting only a portion of the solvent
into the vial, then withdrawing the resultant solution and combining it with
the remainder of the solvent in a larger sterile container.
Buffered Pfizerpen (penicillin g potassium) (penicillin G potassium) for Injection is highly water soluble.
It may be dissolved in small amounts of Water for Injection, or Sterile Isotonic
Sodium Chloride Solution for Parenteral Use. All solutions should be stored
in a refrigerator. When refrigerated, penicillin solutions may be stored for
seven days without significant loss of potency.
Buffered Pfizerpen (penicillin g potassium) for Injection may be given intramuscularly or by continuous
intravenous drip for dosages of 500,000, 1,000,000, or 5,000,000 units. It is
also suitable for intrapleural, intraarticular, and other local instillations.
THE 20,000,000 UNIT DOSAGE MAY BE ADMINISTERED BY INTRAVENOUS INFUSION ONLY.
Intramuscular Injection: Keep total volume of injection small. The
intramuscular route is the preferred route of administration. Solutions containing
up to 100,000 units of penicillin per mL of diluent may be used with a minimum
of discomfort. Greater concentration of penicillin G per mL is physically
possible and may be employed where therapy demands. When large dosages are
required, it may be advisable to administer aqueous solutions of penicillin
by means of continuous intravenous drip.
Continuous Intravenous Drip: Determine the volume of fluid and rate
of its administration required by the patient in a 24 hour period in the usual
manner for fluid therapy, and add the appropriate daily dosage of penicillin
to this fluid. For example, if an adult patient requires 2 liters of fluid
in 24 hours and a daily dosage of 10 million units of penicillin, add 5 million
units to 1 liter and adjust the rate of flow so the liter will be infused
in 12 hours.
Intrapleural or Other Local Infusion: If fluid is aspirated, give
infusion in a volume equal to ¼ or ½ the amount of fluid aspirated, otherwise,
prepare as for intramuscular injection.
Intrathecal Use: The intrathecal use of penicillin in meningitis
must be highly individualized. It should be employed only with full consideration
of the possible irritating effects of penicillin when used by this route.
The preferred route of therapy in bacterial meningitides is intravenous, supplemented
by intramuscular injection.
Parenteral drug products should be inspected visually for particulate matter
and discoloration prior to administration, whenever solution and container permit.
Sterile solution may be left in refrigerator for one week without significant
loss of potency.
HOW SUPPLIED
Buffered Pfizerpen® (penicillin G potassium) for Injection is available
in vials containing respectively 5,000,000 units x10's (NDC 0049-0520-83) and
20,000,000 units x1's (NDC 0049-0530-28); buffered (penicillin g potassium) with sodium citrate and citric
acid to an optimum pH.
Each million units contains approximately 6.8 milligrams of sodium (0.3 mEq)
and 65.6 milligrams of potassium (1.68 mEq).
Store the dry powder below 86°F (30°C).
REFERENCE
1. American Heart Association, 1977. Prevention of bacterial
endocarditis. Circulation. 56:139A-143A.
Distributed by: Roerig, Division of Pfizer Inc, NY, NY 10017.
Revised December 2005. FDA revision date: 7/14/1994