Tobramycin + Dexamethasone

Dexamethasone (0.1%) + Tobramycin (0.3%)
Price: Suspension (5ml): ₹100 - ₹150
Mfr: Ajanta Pharma Ltd. | Form: Ophthalmic Suspension

📋 Clinical Overview

A sterile, topical ophthalmic suspension/ointment combining a potent corticosteroid (Dexamethasone) with a broad-spectrum aminoglycoside antibiotic (Tobramycin). It is primarily indicated for the treatment of steroid-responsive inflammatory ocular conditions where the risk of superficial bacterial infection is high or where such an infection already exists. This combination provides anti-inflammatory, anti-allergic, and antibacterial actions.

💊 Dosage & Administration

Adult: Suspension: Instill 1 or 2 drops into the conjunctival sac(s) every 4 to 6 hours. In severe disease, may be used hourly initially, tapering as inflammation subsides. Ointment: Apply a small ribbon (approx. 1 cm) into the conjunctival sac up to 3-4 times daily.

Note: Shake suspension well before use. Wash hands. Tilt head back, pull lower eyelid down to form a pouch. Instill drops/apply ointment without touching the tip to the eye or any surface. Close eye gently for 1-2 minutes. Apply gentle pressure to the nasolacrimal duct (inner corner of eye) for 1 minute to reduce systemic absorption. Wait at least 5-10 minutes before instilling any other ophthalmic medication.

⚠️ Contraindications

  • Hypersensitivity to dexamethasone, tobramycin, other aminoglycosides, or any component of the formulation.
  • Viral diseases of the cornea and conjunctiva (e.g., epithelial herpes simplex keratitis, vaccinia, varicella).
  • Fungal diseases of ocular structures.
  • Mycobacterial infection of the eye.
  • Purulent untreated infections.

🔬 Mechanism of Action

Dexamethasone exerts potent anti-inflammatory, anti-allergic, and anti-proliferative effects by inducing phospholipase A2 inhibitory proteins (lipocortins), which control the biosynthesis of potent mediators of inflammation like prostaglandins and leukotrienes. It suppresses migration of polymorphonuclear leukocytes and reverses increased capillary permeability. Tobramycin is a bactericidal aminoglycoside that binds irreversibly to the 30S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis and causing misreading of the genetic code.

🤕 Side Effects

  • Transient ocular burning or stinging upon instillation
  • Blurred vision (especially with ointment)
  • Foreign body sensation
  • Mild conjunctival hyperemia
  • Itching

🤰 Special Populations

Pregnancy: Category C (US FDA). Dexamethasone and tobramycin cross the placenta. Topical use is generally considered low risk, but should be used only if the potential benefit justifies the potential risk to the fetus. Avoid prolonged or high-dose use. Consult physician.

Driving: May cause transient blurred vision after instillation. Patients should not drive or operate machinery until vision clears.

🔄 Drug Interactions

Other Aminoglycosides (systemic or topical)Increased risk of ototoxicity and nephrotoxicity (additive).Moderate
Systemic CorticosteroidsAdditive systemic steroid effects, increasing risk of hypercortisolism.Moderate
Neuromuscular Blocking Agents (e.g., Succinylcholine)Tobramycin may potentiate neuromuscular blockade, leading to respiratory depression.Major
Loop Diuretics (e.g., Furosemide)Increased risk of ototoxicity when combined with tobramycin.Moderate
CyclosporineConcurrent use may increase risk of cataract formation.Moderate

🔁 Alternatives to Tobramycin + Dexamethasone

Same composition (Dexamethasone (0.1%) + Tobramycin (0.3%)), different brands:

Dazitob Tobracort Tobradex TobraDex