Bicillin L-A
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BICILLIN L-A
BICILLIN L-A for Syphilis
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BICILLIN L-A Dosage and Administration
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Special Cases
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BICILLIN C-R
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Important Safety Information

BICILLIN® L-A: Dosage and Administration

Penicillin G benzathine has extremely low solubility. The drug is slowly released from intramuscular injection sites and is hydrolyzed to penicillin G. This results in blood serum levels that are lower, and much more prolonged than for other parenteral penicillins.2

Penicillin G exerts a bactericidal action against Treponema pallidum (the bacterium that causes syphilis) while the cells are actively multiplying.2 This bacterium divides slowly.12 For this reason, it is necessary to maintain adequate serum levels of penicillin for many days.12

DOSAGE AND ADMINISTRATION
penicillin g benzathine injectable suspension 
for the treatment of syphilis in non-penicillin-allergic patientsa,b
PATIENT TYPE STAGE DOSE
Adult Primary, secondary, and early latent (< year) 2.4 million units intramuscular (IM), single dose c,d,e,6
Adult Late latent (>1 year) or latent syphilis of unknown duration and tertiary syphilis (either cardiovascular or gummatous)f 7.2 million units, administered as 3 doses of 2.4 million units IM each week at 1-week intervals d,e,6
Pediatric Primary, secondary, and early latent (<1 year)g 50,000 units/kg IM, up to the adult dose of 2.4 million units in a single dose d,e,6
Pediatric Acquired syphilis in the late latent stage, with normal cerebrospinal fluid resultsg 50,000 units/kg IM, up to the adult dose of 2.4 million units in a single dose, administered as 3 doses at 1-week intervals (total dose of 150,000 units/kg up to the adult total dose of 7.2 million units) d,e,6
 

BICILLIN® L-A is the only formulation of intramuscular penicillin G benzathine that is FDA-approved for the treatment of syphilis. 10,12

  1. 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 BICILLIN® L-A, careful inquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens. If allergic reaction occurs, BICILLIN® L-A 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.2
  2. For alternative regimens for penicillin-allergic patients, see the CDC STD treatment guidelines, 2006.
  3. Single dose: Two injections. To minimize the volume of a single intramuscular injection, some clinicians elect to inject BICILLIN® in 2 divided doses of 1,200,000 units, administering 1 injection into each buttock.16
  4. BICILLIN® L-A is intended for intramuscular injection ONLY. Do not inject into or near an artery or nerve or intravenously. Do not admix with other intravenous solutions.2
  5. BICILLIN® L-A should be administered by deep, intramuscular injection in the upper, outer quadrant of 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.2
  6. Patients with cardiovascular or gummatous syphilis should be managed in consultation with an infectious disease specialist.7
  7. Infants 1 month of age or older and children with syphilis should have a CSF examination to detect asymptomatic neurosyphilis. Birth and maternal records should be reviewed in an effort to differentiate congenital from acquired syphilis. Children with acquired syphilis should be evaluated for assault or abuse (e.g., in consultation with child-protection services) and treated using the regimen listed in the table above.7

    For more information on the diagnosis and management of congenital syphilis, see the CDC STD treatment guidelines, 2006.

Relevant links

When treating syphilis, consider these special cases.

See the prescribing information for BICILLIN® L-A and BICILLIN® L-A Pediatric.

Note: BICILLIN® L-A is indicated for syphilis. BICILLIN® C-R is not.2,3 Learn about BICILLIN® C-R (penicillin G benzathine and penicillin G procaine injectable suspension).