Chlorphen

• Ophthalmic Infections:
  Treatment of bacterial conjunctivitis, blepharitis, keratitis, and other superficial eye infections caused by susceptible bacteria.
• Otic Infections:
  Used for bacterial external ear infections (otitis externa) caused by susceptible organisms.
• Topical Use on Skin and Mucous Membranes:
  Occasionally used in formulations for superficial skin infections or minor wounds when local anesthesia is beneficial.

• Route: Topical application (eye drops, ointment, or ear drops).
• Ophthalmic Use:
  Apply 1 to 2 drops every 2 to 6 hours depending on severity. For ointment, apply a small strip in the conjunctival sac 2 to 4 times daily.
• Otic Use:
  Instill 3 to 4 drops into the affected ear 3 to 4 times daily.
• Duration:
  Typically 7 to 14 days or until clinical resolution.
• Special Populations:
  Use with caution in pediatric and elderly patients; no dose adjustments typically necessary for topical use.
• Precautions:
  Avoid contact with contact lenses during treatment; remove lenses before application and wait at least 15 minutes before reinsertion.

• Chloramphenicol:
  Acts as a broad-spectrum bacteriostatic antibiotic by binding reversibly to the 50S subunit of bacterial ribosomes, inhibiting peptidyl transferase activity, thereby preventing peptide bond formation and protein synthesis, leading to inhibition of bacterial growth.
• Lidocaine Hydrochloride:
  A local anesthetic that blocks voltage-gated sodium channels in neuronal membranes, inhibiting nerve impulse initiation and conduction, resulting in temporary loss of sensation and analgesia at the site of application.

Together, they provide simultaneous antibacterial action and local pain relief in infected areas.

• Absorption:
  Minimal systemic absorption when applied topically to eyes or ears. Lidocaine may have some local absorption but systemic levels remain low.
• Distribution:
  Limited to local tissues at the site of administration.
• Metabolism:
  Systemic metabolism negligible with topical use. If absorbed, lidocaine is metabolized in the liver by cytochrome P450 enzymes.
• Elimination:
  Systemic elimination is primarily renal for lidocaine metabolites; chloramphenicol systemic elimination irrelevant with topical use.
• Half-life:
  Not clinically significant with topical use.

• Pregnancy:
  Category C (Chloramphenicol); use only if benefits justify risks. Lidocaine topical use is generally considered low risk.
• Lactation:
  Caution advised; chloramphenicol may be excreted in breast milk. Topical use is unlikely to cause significant systemic exposure, but caution is recommended.

• Chloramphenicol: Broad-spectrum antibiotic
• Lidocaine Hydrochloride: Local anesthetic
• Combination: Antibacterial + local analgesic topical agent

• Known hypersensitivity to chloramphenicol, lidocaine, or any excipients.
• Patients with history of blood dyscrasias (due to chloramphenicol risk).
• Severe hepatic or renal impairment (for systemic use; topical use typically safe).
• Use in neonates or infants (chloramphenicol risk).
• Application on deep wounds or severe skin infections where systemic absorption could be significant.

• Monitor for signs of hypersensitivity or allergic reactions.
• Avoid prolonged use to reduce risk of local irritation or resistance.
• Use with caution in patients with history of bone marrow disorders due to chloramphenicol component.
• Avoid contact with contact lenses during ophthalmic treatment.
• Do not apply to large areas of broken skin or mucous membranes.
• Discontinue if severe local irritation, dermatitis, or systemic adverse effects occur.

Common:

• Local irritation, redness, itching, burning sensation.
• Transient blurred vision (ophthalmic use).
• Mild stinging upon application.

Serious/Rare:

• Allergic reactions including rash or anaphylaxis.
• Aplastic anemia (rare, associated with chloramphenicol systemic absorption).
• Contact dermatitis.
• Systemic toxicity unlikely but possible if overused on large areas.

• Minimal systemic absorption reduces significant drug interactions.
• Concurrent use with other topical ophthalmic or otic products should be done cautiously to avoid additive irritation.
• Systemic chloramphenicol interacts with enzyme inducers or inhibitors, but not clinically relevant here.
• Alcohol or CNS depressants may potentiate lidocaine’s systemic toxicity if absorbed systemically in significant amounts (rare with topical use).

• No major recent changes to indications or dosing.
• Emphasis on avoiding unnecessary use to prevent antibiotic resistance.
• Recommendations to avoid use in neonates and infants due to chloramphenicol risk.
• Guidelines emphasize monitoring for rare but serious adverse effects with chloramphenicol.

• Store at controlled room temperature 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Keep container tightly closed.
• For ophthalmic formulations, avoid contamination; do not touch dropper tip to any surface.
• Discard any unused portion after recommended period following opening.