Lapen Injection

Lapen is indicated in-

• The treatment of penicillin-sensitive infections where initial high blood levels are not required.
• The prophylaxis of penicillin-sensitive secondary infections especially in children. It is particularly valuable in continuous prophylaxis against rheumatic fever and streptococcal infections.
• Prophylaxis of streptococcal impetigo
• Treatment of acute otitis media
• Treatment of syphilis
• Treatment of diphtheria carriers

Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs); which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.

Treatment of infection: 0.3 to 1.2 million units repeated every five to seven days.

Prophylaxis of rheumatic fever: 1.2 million units every three weeks.

Specific dosage schedule: Treatment of group-A β-haemolytic streptococcal infections: A single intramuscular dose of 600,000 units.

Prevention of rheumatic fever: Monthly injection of a single dose of 1.2 million units is the most effective regimen for preventing further attacks of rheumatic fever.

Treatment of acute otitis media: A single injection of 6 million units.

• Early syphilis- 2.4 million units as a single dose.
• Late syphilis: 2.4 million units weekly for three successive weeks.
• Neurosyphilis: Benzylpenicillin, intravenously, 2 to 4 million units every 4 hours for 10 days, followed by benzathine penicillin intramuscularly, 2.4 million units weekly for three successive weeks.
• Congenital syphilis: Asymptomatic infants with normal cerebrospinal fluid, intramuscularly 50,000 units per kg in a single dose.

Primary and secondary syphilis have been treated with single injections of 2.4 million units of long acting benzathine penicillin (Benzapen) weekly for 2 to 4 weeks with satisfactory results.

No potentially hazardous interactions have been described.

Hypersensitivity to penicillins

The toxicity of penicillins is generally low, but in a small number of patients penicillin can cause sensitization and allergic reactions. Acute, lifethreatening anaphylactic reactions are rare, but they do occur.

Intramuscular injection of Lapen can cause moderate burning discomfort, local pain, and deep muscle soreness and tenderness at the site of injection, lasting for one to three days in about 10% of patients. Some patients had low-grade fever (102˚F) associated with local pain and tenderness. This febrile reaction disappeared within 24 to 48 hours.

Pregnancy category B. Benzathine Penicillin should not be administered during pregnancy unless in the judgment of the physician such administration is clinically justifiable. Special care should be taken in the first three months of pregnancy.

As penicillin appears in breast milk, it is probably best for a mother to stop breast-feeding while being given penicillin to avoid exposing the infant to the drug unnecessarily.

Patient with previous hypersensitivity reactions to cephalosporins, history of allergy, asthma, seizure disorder. Not intended for IV or intra-arterial admin or inj near major peripheral nerves of blood vessels. Prolonged use may result in bacterial or fungal superinfection. Renal impairment.

Long acting penicillin

Store between 2-8°C. Do not freeze.