OPELE LOTION

Indications

• Food preservative
• Treatment of urea cycle disorders
• Metabolic disorders involving benzoyl-CoA

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines based on condition.

Adults: Refer to the BNF for specific dosing guidelines based on condition.

Mechanism of action

Benzoate acts mainly by inhibiting the growth of bacteria and fungi through its ability to lower the pH, creating an environment that is less favorable for microbial growth. It is also involved in metabolic pathways where it helps in the conjugation of toxic substances, facilitating their excretion from the body.

Pharmacodynamics

Benzoate is known for its antimicrobial properties, which are particularly effective against a wide range of fungi and bacteria. Its efficacy as a preservative is due to its ability to penetrate microbial cell membranes and disrupt their metabolic processes. Additionally, it has been observed to modulate various metabolic pathways, particularly those associated with aromatic compound degradation.

Pharmacokinetics

After ingestion, benzoate is rapidly absorbed in the gastrointestinal tract. It is metabolized primarily in the liver, where it undergoes conjugation with glycine to form hippurate, which is then excreted in the urine. The half-life of benzoate varies depending on individual metabolic rates but is generally short due to its efficient conversion and excretion.

Pregnancy

There is limited data on the use of benzoate in pregnancy. Consultation with healthcare professionals is advised before use.

Breast-feeding

Limited data is available on the excretion of benzoate in breast milk. Caution is recommended when administering to nursing mothers.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Indications

• Bacterial infections
• Pneumonia
• Meningitis
• Syphilis
• Endocarditis
• Skin and soft tissue infections

Dosage

Children: Paediatric dosing for benzylpenicillin is determined by the child's weight and the severity of the infection. Refer to the BNF for Children for specific dosing guidelines.

Adults: The usual adult dose for benzylpenicillin varies based on the type and severity of the infection. It is generally administered via intramuscular or intravenous routes. For severe infections, doses may range from 1 to 4 million units every 4 to 6 hours.

Mechanism of action

Benzylpenicillin exerts its antibacterial effects by inhibiting the synthesis of bacterial cell walls. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, disrupting the transpeptidation process, which is crucial for cross-linking peptidoglycan layers. This inhibition leads to cell lysis and death of the bacteria.

Pharmacodynamics

Benzylpenicillin demonstrates time-dependent bactericidal activity, meaning its effectiveness is related to the duration of time the drug concentration remains above the minimum inhibitory concentration (MIC) for the target bacteria. It has a narrow spectrum of activity, primarily targeting Gram-positive cocci and some Gram-negative rods.

Pharmacokinetics

Benzylpenicillin is typically administered parenterally due to poor oral absorption. It is rapidly distributed throughout the body and can penetrate various tissues, including the central nervous system during inflammation. The drug is primarily eliminated by renal excretion, with a half-life of approximately 30 minutes to 1 hour in healthy individuals. Dosage adjustments may be necessary in patients with renal impairment.

Interactions

• leflunomide+benzylpenicillin: Unknown (increases exposure)
• nitisinone+benzylpenicillin: Unknown (increases exposure)
• teriflunomide+benzylpenicillin: Unknown (increases exposure)

Pregnancy

Benzylpenicillin is generally considered safe to use during pregnancy, as it is a penicillin antibiotic and has a long history of use.

Breast-feeding

Benzylpenicillin is excreted in breast milk in small amounts, but it is not expected to have adverse effects on a nursing infant.

Storage

Store in a cool, dry place, protected from light. Reconstituted solutions should be used promptly or stored in a refrigerator and used within a limited time frame.

Formulations

• Benzylpenicillin injection

Indications

• Nutritional support in patients unable to consume food orally
• Parenteral nutrition
• Drug delivery for lipophilic medications
• Topical applications for skin conditions

Dosage

Children: Refer to specific product guidelines and clinical protocols for paediatric dosing.

Adults: Refer to specific product guidelines and clinical protocols for adult dosing.

Mechanism of action

Emulsions work by reducing the surface tension between the oil and water phases, allowing for the formation of stable droplets. This process is mediated by emulsifying agents, which can be surfactants or natural polymers that stabilize the emulsion and prevent phase separation. The absorption and bioavailability of drugs within the emulsion can be enhanced due to the increased surface area for absorption.

Pharmacodynamics

The pharmacodynamics of emulsions vary based on their composition and formulation. The presence of emulsifying agents can influence the release profile of the active ingredients, allowing for controlled or sustained release. Emulsions can also enhance the solubility of poorly water-soluble drugs, improving their therapeutic effects and minimizing side effects related to high concentrations of active ingredients.

Pharmacokinetics

The pharmacokinetics of emulsions depend on their route of administration and the specific properties of the drug contained within the emulsion. After administration, emulsions can be rapidly absorbed due to their small droplet size, leading to quicker onset of action. The distribution, metabolism, and excretion of the drug will follow the pharmacokinetic principles applicable to the active ingredients, influenced by their solubility and the emulsion's formulation.

Pregnancy

The safety of emulsions during pregnancy depends on the specific type and formulation. Consult relevant guidelines and specific product information.

Breast-feeding

Emulsions may be used while breastfeeding, but specific product information should be consulted to ensure safety.

Storage

Store at room temperature, away from light and moisture. Specific formulations may have unique storage requirements.