KMDURE POWDER FOR INJECTION (Each vial contains Benzylpencillin sodium 1000000 IU)

Indications

• Pneumonia
• Meningitis
• Syphilis
• Endocarditis
• Skin and soft tissue infections
• Bone and joint infections
• Intra-abdominal infections

Dosage

Children: Refer to the BNF for Children for specific dosing guidance based on age, weight, and clinical condition

Adults: Refer to specific guidelines for dosing according to the type and severity of infection. Dosing typically varies based on infection type and patient condition.

Mechanism of action

Benzylpenicillin exerts its antibacterial effect by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins located inside the bacterial cell wall, leading to the disruption of peptidoglycan cross-linking. This interference ultimately results in cell lysis and death of the bacteria, particularly in actively dividing organisms.

Pharmacodynamics

Benzylpenicillin demonstrates time-dependent bactericidal activity, meaning its effectiveness is related to the duration of time that the drug concentration remains above the minimum inhibitory concentration (MIC) for the target bacteria. Its spectrum of activity includes Streptococcus, Staphylococcus (non-penicillinase producing strains), Neisseria meningitidis, and Treponema pallidum. Resistance can occur through the production of beta-lactamases or alterations in penicillin-binding proteins.

Pharmacokinetics

Benzylpenicillin is administered via intramuscular or intravenous routes due to poor oral bioavailability. It is rapidly distributed throughout body tissues and fluids, with a volume of distribution of around 0.2 to 0.3 L/kg. The drug is primarily eliminated by renal excretion, with a half-life of approximately 30 to 60 minutes in patients with normal renal function. Dosage adjustment may be required in patients with renal impairment.

Contra-indications

• Hypersensitivity to benzylpenicillin or any penicillin antibiotics
• Severe allergic reactions to other beta-lactam antibiotics

Adverse effects

• Allergic reactions including rash, urticaria, and anaphylaxis
• Gastrointestinal disturbances such as nausea, vomiting, and diarrhea
• Hematologic reactions including leukopenia and thrombocytopenia
• Neurotoxicity leading to seizures (in cases of high doses or renal impairment)
• Superinfection due to disruption of normal flora

Interactions

• Probenecid may increase benzylpenicillin levels by decreasing renal excretion
• Concurrent use with bacteriostatic antibiotics may reduce efficacy
• Anticoagulants may have altered effects in patients receiving high doses

Precautions

• Use with caution in patients with a history of allergic reactions to penicillins or cephalosporins
• Monitor renal function in patients receiving high doses or prolonged therapy
• Consider cross-reactivity in patients with penicillin allergy when prescribing cephalosporins

Pregnancy

Benzylpenicillin is generally considered safe for use during pregnancy. However, it should only be used if clearly needed, with consultation from a healthcare provider.

Breast-feeding

Benzylpenicillin is excreted in breast milk in small amounts. It is considered safe to use during breastfeeding, but monitoring for potential effects on the infant is advisable.

Storage

Store in a cool, dry place away from light. Once reconstituted, benzylpenicillin should be used promptly or stored in a refrigerator for no more than 24 hours.

Formulations

• Benzylpenicillin sodium injectable solution
• Benzylpenicillin potassium injectable solution