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Tobramycin and Dexamethasone

Generic name: dexamethasone/tobramycin ophthalmic

Brand names: TobraDex, Tobradex ST

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Ointment, ophthalmic:

TobraDex: Tobramycin 0.3% and dexamethasone 0.1% (3.5 g) [contains chlorobutanol]

Suspension, ophthalmic: Tobramycin 0.3% and dexamethasone 0.1% (2.5 mL, 5 mL, 10 mL)

TobraDex: Tobramycin 0.3% and dexamethasone 0.1% (2.5 mL, 5 mL, 10 mL) [contains benzalkonium chloride]

TobraDex ST: Tobramycin 0.3% and dexamethasone 0.05% (5 mL) [contains benzalkonium chloride]


Mechanism of Action

Tobramycin: Interferes with bacterial protein synthesis by binding to 30S ribosomal subunit resulting in a defective bacterial cell membrane.

Dexamethasone: Decreases inflammation by suppression of neutrophil migration, decreased production of inflammatory mediators, and reversal of increased capillary permeability; suppresses normal immune response.

Use: Labeled Indications

Ocular inflammatory conditions: Treatment of steroid-responsive ocular inflammatory conditions (where either a superficial bacterial ocular infection or the risk of a bacterial ocular infection exists) of the palpebral and bulbar conjunctiva, cornea and anterior segment of the globe; chronic anterior uveitis; corneal injury from chemical, radiation or thermal burns; penetration of foreign bodies.


Hypersensitivity to tobramycin, dexamethasone, or any component of the formulation; viral diseases of the cornea and conjunctiva (including epithelial herpes simplex keratitis [dendritic keratitis], vaccinia, varicella); mycobacterial infection of the eye; fungal diseases of ocular structure.

Canadian labeling: Additional contraindications (not in US labeling): Patients with known or suspected hypersensitivity to other aminoglycosides; after uncomplicated removal of a corneal foreign body; untreated parasitic or untreated acute purulent infections of the eye.

Documentation of allergenic cross-reactivity for corticosteroids is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Dosage and Administration

Dosing: Adult

Ocular inflammatory conditions: Ophthalmic:

Ointment: Apply ~1/2-inch ribbon in the conjunctival sac of the affected eye(s) up to 3 to 4 times daily


TobraDex: Instill 1 to 2 drops into the conjunctival sac of the affected eye(s) every 4 to 6 hours; may be increased to 1 to 2 drops every 2 hours for the first 24 to 48 hours, then reduce to less frequent intervals as signs and symptoms improve

TobraDex ST: Instill 1 drop into the conjunctival sac of the affected eye(s) every 4 to 6 hours; may be increased to 1 drop every 2 hours for the first 24 to 48 hours, then reduce to less frequent intervals as signs and symptoms improve

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Ocular inflammatory conditions: Children ≥2 years and Adolescents: Refer to adult dosing.


Contact lenses should not be worn during therapy. For topical ophthalmic use only; to avoid contamination, do not touch container tip to eyelids or other surfaces when placing drops or ointment in eyes.

Ointment: Apply ointment into pocket between eyeball and lower lid; patient should look downward before closing eye.

Suspension: Shake well before using. Tilt head back, instill suspension in conjunctival sac and close eye(s). Apply light finger pressure on lacrimal sac for 1 minute following instillation.



Ointment: Store at 2°C to 25°C (36°F to 77°F).

Suspension: Store at 8°C to 25°C (46°F to 77°F).

TobraDex ST: Store at 2°C to 25°C (36°F to 77°F). Protect from light.

Drug Interactions

CYP3A4 Inhibitors (Strong): May increase the serum concentration of DexAMETHasone (Ophthalmic). Monitor therapy

Nonsteroidal Anti-Inflammatory Agents (Ophthalmic): May enhance the adverse/toxic effect of Corticosteroids (Ophthalmic). Healing of ophthalmic tissue during concomitant administration of ophthalmic products may be delayed. Monitor therapy

Ritodrine: Corticosteroids may enhance the adverse/toxic effect of Ritodrine. Monitor therapy

Adverse Reactions

Frequency not always defined.

Dermatologic: Allergic contact dermatitis

Infection: Secondary infection

Ophthalmic: Conjunctival erythema (<4%), eyelid pruritus (<4%), swelling of eye (<4%), cataract, glaucoma, increased intraocular pressure, keratitis, lacrimation, optic nerve damage

Miscellaneous: Wound healing impairment


Concerns related to adverse effects:

  • Hypersensitivity reactions: Sensitivity to topically applied aminoglycosides may occur; discontinue if sensitivity reaction occurs. Cross-sensitivity to other aminoglycoside antibiotics may occur.
  • Immunosuppression: Prolonged use of corticosteroids may increase the incidence of secondary ocular infections (including fungal infections). Acute purulent ocular infections may be masked or exacerbated with use. Fungal infection should be suspected in any patient with persistent corneal ulceration who has received corticosteroids.
  • Ocular effects: Prolonged use may result in glaucoma, injury to the optic nerve, visual defects in acuity and field of vision, and formation of posterior subcapsular cataracts. Use with caution in presence of glaucoma (steroids increase intraocular pressure). Perforation may occur with topical steroids in diseases which thin the cornea or sclera. Steroid use after cataract surgery may delay healing and increase the incidence of bleb formation. Intraocular pressure should be monitored if this product is used >10 days.

Disease-related concerns:

  • Ocular herpes simplex: Use with extreme caution in patients with a history of ocular herpes simplex; use of corticosteroids may prolong the course and exacerbate severity of infection.

Special populations:

  • Contact lens wearers: May contain benzalkonium chloride (ophthalmic suspension) which may be adsorbed by contact lenses; contact lenses should not be worn during treatment of ophthalmic infections.

Other warnings/precautions:

  • Appropriate use: For topical ophthalmic use only. A maximum of 8 g of ointment or 20 mL of suspension should be prescribed initially; patients should be evaluated prior to additional refills. Patients should be re-evaluated if symptoms do not improve after 2 days. Monitor intraocular pressure if this product is used >10 days. Initial prescription and renewal of medication should be made by health care provider only after examination with the aid of magnification such as slit lamp biomicroscopy or fluorescein staining (if appropriate). Inadvertent contamination of multiple-dose ophthalmic bottle dropper and tips has caused bacterial keratitis.

Monitoring Parameters

Monitor intraocular pressure with use >10 days and in patients with glaucoma; signs/symptoms of secondary infection; re-evaluate if signs and symptoms persist beyond 2 days.


Pregnancy Considerations

Adverse events have been observed with topical corticosteroids in animal reproduction studies. If ophthalmic agents are needed during pregnancy, the minimum effective dose should be used in combination with punctal occlusion to decrease potential exposure to the fetus (Samples 1988). See individual agents.

Patient Education

What is this drug used for?

  • It is used to treat or prevent eye infections.
  • It is used to treat eye swelling.

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

  • Vision changes
  • Eye pain
  • Severe eye irritation
  • Eyelid swelling
  • Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated December 30, 2019.