BICILLIN L-A- penicillin g benzathine injection, suspension
King Pharmaceuticals, Inc.
Bicillin L-A (penicillin G benzathine injectable suspension) is available for deep intramuscular injection. Penicillin G benzathine is prepared by the reaction of dibenzylethylene diamine with two molecules of penicillin G. It is chemically designated as (2S , 5R , 6R )-3,3-Dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid compound with N,N " - dibenzylethylenediamine (2:1), tetrahydrate. It occurs as a white, crystalline powder and is very slightly soluble in water and sparingly soluble in alcohol.
Penicillin G benzathine has an extremely low solubility and, thus, the drug is slowly released from intramuscular injection sites. The drug is hydrolyzed to penicillin G. This combination of hydrolysis and slow absorption results in blood serum levels much lower but much more prolonged than other parenteral penicillins.
Intramuscular administration of 300,000 units of penicillin G benzathine in adults results in blood levels of 0.03 to 0.05 units per mL, which are maintained for 4 to 5 days. Similar blood levels may persist for 10 days following administration of 600,000 units and for 14 days following administration of 1,200,000 units. Blood concentrations of 0.003 units per mL may still be detectable 4 weeks following administration of 1,200,000 units.
Approximately 60% of penicillin G is bound to serum protein. The drug is distributed throughout the body tissues in widely varying amounts. Highest levels are found in the kidneys with lesser amounts in the liver, skin, and intestines. Penicillin G penetrates into all other tissues and the spinal fluid to a lesser degree. With normal kidney function, the drug is excreted rapidly by tubular excretion. In neonates and young infants and in individuals with impaired kidney function, excretion is considerably delayed.
INDICATIONS AND USAGE
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Bicillin L-A and other antibacterial drugs, Bicillin L-A should be used only to treat or prevent infections that are proven or strongly suspected to be caused by 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.
Intramuscular penicillin G benzathine is indicated in the treatment of infections due to penicillin-G-sensitive microorganisms that are susceptible to the low and very prolonged serum levels common to this particular dosage form. Therapy should be guided by bacteriological studies (including sensitivity tests) and by clinical response.
The following infections will usually respond to adequate dosage of intramuscular penicillin G benzathine:
Mild-to-moderate infections of the upper-respiratory tract due to susceptible streptococci.
Venereal infections -Syphilis, yaws, bejel, and pinta.
Medical Conditions in which Penicillin G Benzathine Therapy is indicated as Prophylaxis:
Rheumatic fever and/or chorea -Prophylaxis with penicillin G benzathine has proven effective in preventing recurrence of these conditions. It has also been used as follow-up prophylactic therapy for rheumatic heart disease and acute glomerulonephritis.
Do not inject into or near an artery or nerve.
Injection into or near a nerve may result in permanent neurological damage.
Information for Patients
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.
Patients should be counseled that antibacterial drugs including Bicillin L-A should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Bicillin L-A is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Bicillin L-A or other antibacterial drugs in the future.
Tetracycline, a bacteriostatic antibiotic, may antagonize the bactericidal effect of penicillin, and concurrent use of these drugs should be avoided.
Penicillin in overdosage has the potential to cause neuromuscular hyperirritability or convulsive seizures.
Streptococcal (Group A) Upper Respiratory Infections (for example, pharyngitis)
Adults-a single injection of 1,200,000 units; older pediatric patients-a single injection of 900,000 units; infants and pediatric patients under 60 lbs.-300,000 to 600,000 units.
Syphilis
Primary, secondary, and latent-2,400,000 units (1 dose). Late (tertiary and neurosyphilis)-2,400,000 units at 7-day intervals for three doses.
Congenital-under 2 years of age: 50,000 units/kg/body weight; ages 2 to 12 years: adjust dosage based on adult dosage schedule.
Yaws, Bejel, and Pinta -1,200,000 units (1 injection).
Prophylaxis -for rheumatic fever and glomerulonephritis.
Following an acute attack, penicillin G benzathine (parenteral) may be given in doses of 1,200,000 units once a month or 600,000 units every 2 weeks.
BICILLIN L-A IS INTENDED FOR INTRAMUSCULAR INJECTION ONLY. DO NOT INJECT INTO OR NEAR AN ARTERY OR NERVE, OR INTRAVENOUSLY OR ADMIX WITH OTHER INTRAVENOUS SOLUTIONS. (SEE WARNINGS SECTION.)
Administer by DEEP INTRAMUSCULAR INJECTION in the buttock. In neonates, infants and small children, the midlateral aspect of the thigh may be preferable. When doses are repeated, vary the injection site.
Because of the high concentration of suspended material in this product, the needle may be blocked if the injection is not made at a slow, steady rate.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.
Bicillin L-A (penicillin G benzathine injectable suspension) is supplied in packages of 10 disposable syringes as follows:
1 mL size, containing 600,000 units per syringe, (21 gauge, thin-wall 1 inch needle for pediatric use), NDC 60793-700-10.
2 mL size, containing 1,200,000 units per syringe, (21 gauge, thin-wall 1-1/2 inch needle), NDC 60793-701-10.
4 mL size, containing 2,400,000 units per syringe (18 gauge x 1�1/2 inch needle), NDC 60793-702-10.
Store in a refrigerator, 2� to 8�C (36� to 46�F).
Keep from freezing.
