A fixed-dose combination ophthalmic solution containing an aminoglycoside antibiotic (Tobramycin) and a fourth-generation fluoroquinolone antibiotic (Moxifloxacin). This combination provides broad-spectrum bactericidal coverage against a wide range of Gram-positive, Gram-negative, and atypical ocular pathogens, including many resistant strains. It is primarily indicated for the treatment of bacterial conjunctivitis and is used for prophylaxis and treatment of other superficial ocular infections. The combination aims to enhance efficacy, reduce the potential for resistance development, and provide a convenient dosing regimen.
Adult: Bacterial Conjunctivitis: Instill 1 drop into the affected eye(s) every 4 to 6 hours. For severe infections, may be used every 1-2 hours initially, tapering as infection improves. Bacterial Keratitis: Instill 1 drop every 30 minutes to 1 hour while awake and every 2-4 hours during night for first 24-48 hours, then reduce frequency.
Note: 1. Wash hands. 2. Tilt head back. 3. Gently pull lower eyelid down to form a pouch. 4. Instill prescribed number of drops. 5. Close eyes gently for 1-2 minutes, applying gentle pressure to the nasolacrimal duct (inner corner of eye) to minimize systemic absorption. 6. Do not touch dropper tip to eye or any surface. 7. Wait at least 5-10 minutes before instilling any other eye medication.
The combination exerts a synergistic bactericidal effect by targeting two different essential bacterial processes. Tobramycin binds irreversibly to the bacterial 30S ribosomal subunit, inhibiting protein synthesis and causing misreading of mRNA. Moxifloxacin inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes critical for DNA replication, transcription, repair, and recombination. This dual mechanism broadens the spectrum of activity and reduces the likelihood of resistance.
Pregnancy: Category C (US FDA). Animal studies with tobramycin show risk of fetal harm (8th cranial nerve toxicity). No adequate human studies. Moxifloxacin: Risk of arthropathy in immature animals. Use only if the potential benefit justifies the potential risk to the fetus.
Driving: May cause transient blurred vision immediately after instillation. Patients should not drive or operate machinery until vision clears.
| Other Aminoglycosides (e.g., Gentamicin, systemic) | Additive risk of ototoxicity and nephrotoxicity if significant systemic absorption occurs. | Moderate |
| Oral/IV Fluoroquinolones (e.g., Ciprofloxacin, Levofloxacin) | Theoretical additive risk of quinolone-associated adverse effects (CNS, tendon, QT prolongation). | Low |
| Neuromuscular Blocking Agents (e.g., Succinylcholine) | Aminoglycosides may potentiate neuromuscular blockade, leading to respiratory depression. | Moderate |
| Loop Diuretics (e.g., Furosemide) | May increase the risk of aminoglycoside-induced ototoxicity. | Moderate |
| Corticosteroids (topical ocular) | May mask signs of infection or enhance spread of infection if used in an undiagnosed condition. | High |
Same composition (Tobramycin (0.3% w/v) + Moxifloxacin (0.5% w/v)), different brands: