Neosporin

Description

Neosporin Dusting Powder: Clinical Information

Neosporin Dusting Powder is indicated for the treatment of bacterial skin infections.

Dosage and Administration

• Adults: Apply topically 2-4 times per day.
• Children: Apply topically 2-4 times per day.

Contraindications

Neosporin Dusting Powder is contraindicated in patients with:

• Hypersensitivity to aminoglycosides.
• Pre-existing nerve deafness.
• Neonates and infants under 2 years of age.

Precautions

• Avoid application in large quantities or prolonged use.
• Use with caution during pregnancy and lactation.
• Use with caution in patients with liver and renal impairment.

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 effects with other aminoglycosides (e.g., paromomycin), bacitracin, cisplatin, vancomycin, amphotericin B, polymyxin B, colistin, and viomycin.
  • Enhanced toxicity with potent diuretics (e.g., ethacrynic acid, furosemide).
  • May impair the absorption of other drugs (e.g., phenoxymethylpenicillin, digoxin, methotrexate, and some vitamins).
  • May reduce the efficacy of oral contraceptives (OCs).
  • May enhance the effect of acarbose.
  • May enhance the effect of non-depolarizing muscle relaxants.
  • May antagonize the parasympathomimetic effect of neostigmine and pyridostigmine.
  • May increase the risk of hypocalcaemia in patients receiving bisphosphonates.
  • May alter INR when given with anticoagulants.
  • May inactivate oral typhoid vaccine.

Adverse Effects

• Common (>10% of patients): Allergic contact dermatitis (60%).

Mechanism of Action

Neomycin, an aminoglycoside with an antimicrobial spectrum similar to gentamicin, works by binding to the 30S subunits of the bacterial ribosome, thereby inhibiting protein synthesis and disrupting DNA synthesis. It is effective against many gram-negative aerobes and some strains of staphylococci.

Bacitracin, on the other hand, inhibits bacterial cell wall synthesis. It 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).

These two antibiotics are often combined in topical preparations to provide broad-spectrum antibacterial coverage.

Note: Neosporin 5000IU + 3400IU Dusting Powder is manufactured by Glaxo SmithKline Pharmaceuticals Ltd. Its generic name is Bacitracin Zinc + Neomycin Sulphate Topical. Neosporin is available in Nepal. This information from the Farmaco Nepal drug index is not intended for diagnosis, medical advice, or treatment; neither is it a substitute for the exercise of professional judgment