TobraDex® / TobraDex ST®
tobramycin 0.3% / dexamethasone 0.1% ophthalmic suspension or gel
Clinical Snapshot
TobraDex combines tobramycin (aminoglycoside antibiotic) with dexamethasone (corticosteroid) in a single formulation, providing simultaneous anti-infective and anti-inflammatory coverage. It is widely used for blepharokeratoconjunctivitis, postoperative prophylaxis, and conditions where both infection risk and inflammation are present.
Mechanism of Action
Tobramycin inhibits bacterial protein synthesis by binding the 30S ribosomal subunit, providing broad-spectrum gram-negative and gram-positive coverage. Dexamethasone suppresses the inflammatory cascade via glucocorticoid receptor activation.
Common Clinical Applications
- Blepharokeratoconjunctivitis
- Postoperative inflammation with infection risk
- Bacterial conjunctivitis with significant inflammatory component
- Lid margin disease with inflammatory and infectious components
Typical Dosing Principles
One to two drops every 4–6 hours (suspension) or a small ribbon of gel twice daily (ST formulation). Shake well before use.
Dosing information is provided for educational purposes. Always consult current prescribing information for specific dosing protocols.
Important Precautions
- Dexamethasone component carries IOP elevation risk — monitor with extended use.
- Tobramycin resistance is possible with prolonged use.
- Contraindicated in viral, fungal, and mycobacterial infections.
- Not appropriate as monotherapy for anterior uveitis — dexamethasone concentration may be insufficient.
Clinical Pearls
- The combination formulation simplifies dosing when both anti-infective and anti-inflammatory coverage are needed.
- TobraDex ST (gel formulation) provides improved comfort and extended contact time.
- IOP monitoring is appropriate with any extended course due to the dexamethasone component.
- Useful for blepharokeratoconjunctivitis where lid margin bacteria and surface inflammation coexist.
Commonly Associated Disease States
Select any disease state to explore its full entry in the Disease State Library.
Blepharitis
An extremely common condition that frequently coexists with dry eye disease and MGD; a significant contributor to chronic ocular surface symptoms and a risk factor for recurrent hordeola and chalazia.
Bacterial Conjunctivitis
Demodex Blepharitis
Increasingly recognized as a distinct and highly prevalent subtype of blepharitis; the first FDA-approved treatment (Xdemvy®) has elevated its clinical profile and the importance of accurate diagnosis.
This entry is an educational reference designed to support clinical reasoning and therapeutic awareness. It does not constitute medical advice, establish a standard of care, or replace individualized patient assessment. Clinicians should consult current prescribing information before initiating any therapy.