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Topical ophthalmic (steroid + aminoglycoside) Pregnancy: Not recommended during pregnancy — there are no or limited data from topical ocular use of tobramycin and dexamethasone in pregnant women; prolonged or repeated corticosteroid use in pregnancy has been associated with intra-uterine growth retardation (§4.6). Breast-feeding: a risk to the suckling child cannot be excluded; decide whether to stop breast-feeding or the medicine.

Dexamethasone with tobramycin

Brand names: TobraDex

This combined eye preparation contains the corticosteroid dexamethasone with the aminoglycoside antibiotic tobramycin, used for steroid-responsive ocular inflammation where a susceptible bacterial infection is present or at risk, including after eye surgery.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: One drop instilled into the conjunctival sac(s)
Route: Ocular (topical) — instil into the conjunctival sac; shake the bottle well before use
Frequency: Every 4 to 6 hours while the patient is awake
Max: Dosing should continue for 14 days, not to exceed a maximum of 24 days
During the initial 24 to 48 hours the dosage may be increased to one drop every two hours while the patient is awake. Frequency should be decreased gradually as warranted by improvement in clinical signs; care should be taken not to discontinue therapy prematurely. Gently closing the eyelid(s) and nasolacrimal occlusion for at least 1 minute after instillation is recommended — this may reduce systemic absorption and systemic side effects. If other topical ophthalmic medicines are used concomitantly, allow an interval of 5 minutes between successive applications; eye ointments should be administered last. Elderly: clinical studies indicate dosage modifications are not required. Paediatric population: may be used in children 2 years of age and older at the SAME dose as in adults (no per-kg dosing is given); safety and efficacy in children younger than 2 years have not been established and no data are available. Intraocular pressure should be monitored from the outset, especially in children under 6 years, in whom steroid-induced ocular hypertension may be greater and occur earlier than in adults. For topical use only — not for injection or oral use. Source SPC is Tobradex/Tobrasone Eye Drops.

Dose adjustments

Renal

Not studied in patients with hepatic or renal impairment (§4.2) — no dose recommendation is given for these populations

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to tobramycin or dexamethasone or to any of the excipients
  • Herpes simplex keratitis
  • Vaccinia, varicella and other viral disease of the cornea and conjunctiva
  • Mycobacterial infections of the eye (e.g. Mycobacterium tuberculosis, M. leprae, M. avium)
  • Fungal diseases of ocular structures or untreated parasitic eye infections
  • Untreated purulent infection of the eye

Side effects

  • Eye pain (uncommon)
  • Increased intraocular pressure / ocular hypertension (uncommon)
  • Eye irritation — burning upon instillation (uncommon)
  • Eye pruritus and ocular discomfort (uncommon)
  • Headache (uncommon)
  • Not known: anaphylactic reaction, hypersensitivity, Cushing's syndrome, adrenal suppression

Interactions

  • No §4.5 interactions section was captured in the source bundle — clinician to check §4.5 of the SPC
  • §4.4 warning: CYP3A4 inhibitors (including ritonavir and cobicistat) increase the risk of Cushing's syndrome / adrenal suppression from systemically absorbed ocular dexamethasone

Clinical monograph

How it works

Dexamethasone suppresses inflammation by inhibiting inflammatory mediators and vascular permeability, while tobramycin binds the bacterial 30S ribosomal subunit to inhibit protein synthesis, providing broad activity especially against Gram-negative organisms including Pseudomonas.

Prescribing in practice

  • The corticosteroid component must not be used in undiagnosed red eye or suspected herpes simplex (dendritic) keratitis, where it risks corneal perforation, so a viral cause must be excluded first.
  • Prolonged use can raise intraocular pressure and promote cataract and secondary infection, so treatment should be short and supervised.
  • Tobramycin may cause local hypersensitivity and surface toxicity; discontinue if allergic reaction or persistent irritation develops.

Monitoring

Monitor intraocular pressure with extended use and review corneal status and clinical response, stopping if infection or inflammation worsens.

Counselling the patient

  • Use only for the prescribed short course and shake the suspension before instilling.
  • Report increasing pain, redness, swelling or any change in vision promptly.
  • Remove contact lenses during treatment unless your clinician advises otherwise.

Evidence & guidelines

Fixed dexamethasone-tobramycin eye preparations are an established choice for post-operative and infective-inflammatory ocular conditions, with safety depending on excluding viral keratitis and limiting course length.

Reference: RCOphth; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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