Like other aminoglycosides, the bactericidal activity of Tobramycin is taken up into sensitive bacterial cells by an active transport process. Within the cell Tobramycin bind to the 30s, and to some extent to the 50s subunits of the bacterial ribosome, inhibiting protein synthesis and generating errors in the transcription of the genetic code. The manner in which cell death is brought about is imperfectly understood, and other mechanisms may contribute, including effects on membrane permeability.

Tobramycin is a topical antibiotic indicated in the treatment of external bacterial infections of the eye caused by susceptible organisms. Such as,

Gram-positive bacteria: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus spp. of group A beta-hemolytic and some nonhemolytic species.

Gram-negative bacteria: E.coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella spp., Proteusmirabillis, Proteus vulgaris, Haemophilus influenzae, Morganella morganii, Acinetobacter calcoaceticus, Providentia, Serratia, Salmonella spp and some strains of Neisseria.

Ophthalmic ointment:

• In mild to moderate infection, apply a small amount 2-3 times daily into the conjunctival sac(s).
• In severe cases of infection, apply a small amount 3-4 times daily into the conjunctival sac(s) until improvement is obtained, then reduce the dose gradually.

Ophthalmic solution:

• In mild to moderate infections: Instill 1or 2 drops into the affected eye(s) every 4 hours.
• In severe infections: Instill 2 drops into the affected eye(s) every hour until improvement is observed.

Pediatric use: Safety and effectiveness in children below the age of 1 year have not been established.

It is contraindicated in patients who are hypersensitive to Tobramycin or any of the ingredients of the preparation.

The most frequent side effect of Tobramycin ophthalmic solution is localized ocular toxicity, conjunctival erythema, hypersensitivity including lid itching and swelling.

Overdose Effects

Sign and symptoms of overdose may be similar to side effects as described above.

Minor sensitivity may occur to topically applied aminoglycosides in some patients. If a sensitivity reaction occurs, discontinue use. Prolonged use may result in overgrowth of nonsusceptible organisms and fungi.

Pregnancy & Lactation

Pregnancy Category B. There are no adequate and well-controlled studies in pregnant women. This drug should only be used during pregnancy, if the potential benefits outweigh the possible risk to the fetus. Drug may excreted into human milk. A decision should be made whether to discontinue nursing or to taking the drug.