Bacitracin Zinc + Neomycin Sulphate + Polymixin B Eye prep

Indications

Bacitracin Zinc + Neomycin Sulphate + Polymixin B Eye prep is used for: Bacterial ocular infections

Adult Dose

Adult: Eye Drop: 1-2 drops 3-4 times daily. Eye ointment: Apply 1/2 inch ribbon of ointment to conjunctival sac of affected eye(s) q3-4hr for 7-10 days for acute infections

Child Dose

Child: Eye Drop: 1-2 drops 3-4 times daily. Eye ointment: Apply 1/2 inch ribbon of ointment to conjunctival sac of affected eye(s) q3-4hr for 7-10 days for acute infections

Renal Dose

Administration

Contra Indications

Hypersensitivity

Precautions

Excessive use of the topical preparation may lead to substantial systemic absorption which may lead to nephrotoxicity (polymyxin B sulfate) and neurotoxicity (bacitracin). Prolonged use of the antibacterial preparation may cause overgrowth of non-susceptible organisms, including fungi. Pregnancy and lactation. Lacation: Excretion in breast milk unknown; caution

Pregnancy-Lactation

Interactions

Bacitracin Zinc: Increased risk of nephrotoxicity when used with other nephrotoxic drugs. May enhance the action of neuromuscular-blocking agents. Neomycin Sulphate: Additive nephrotoxic and neurotoxic effect w/ other aminoglycosides (e.g. paromomycin), bacitracin, cisplatin, vancomycin, amphotericin B, polymyxin B, colistin and viomycin. Enhanced toxicity w/ potent diuretics (e.g. ethacrynic acid, furosemide). May impair the absorption of other drugs (e.g. phenoxymethylpenicillin, digoxin, methotrexate and some vit). May reduce the efficacy of OCs. May enhance the effect of acarbose. May enhance the effect of non-depolarising muscle relaxants. May antagonise the parasympathomimetic effect of neostigmine and pyridostigmine. May increase the risk of hypocalcaemia in patients receiving bisphosphonates. May alter INR when given w/ anticoagulants. May inactivate oral typhoid vaccine. Polymixin B: Potentially Fatal: Additive neurotoxic or nephrotoxic effect w/ bacitracin, streptomycin, neomycin, kanamycin, gentamicin, tobramycin, amikacin, cephaloridine, paromomycin, viomycin, colistin. Increased risk of resp paralysis w/ neuromuscular blockers (e.g. anaesthetics, muscle relaxants).

Adverse Effects

Side effects of Bacitracin Zinc + Neomycin Sulphate + Polymixin B Eye prep : Rash, itching, burning, anaphylactic reactions, swelling, conjunctival erythema.

Mechanism of Action

Neomycin, an aminoglyoside with antimicrobial spectrum similar to gentamicin, binds to the 30S subunits of the bacterial ribosome, inhibiting protein synthesis and thereby disrupting DNA synthesis. It is active against many gram-negative aerobes and against some strains of staphylococci. Bacitracin, on the other hand, inhibits bacterial cell wall synthesis and is active against many gram-positive bacteria (e.g. staphylococci, streptococci, corynebacteria and clostridia) and some gram-negative species (e.g. Neisseria and Haemophilus influenzae). They are often found in combinations in topical preparations as broad spectrum antibacterial agents. Polymyxin B disrupts the bacterial cytoplasmic membrane of mostly gm-ve organisms allowing leakage of intracellular constituents by binding to membrane phospholipids.