Dextrobac0.1%+0.3%

Dextrobac is a combination ophthalmic corticosteroid-antibiotic product indicated for:

• Established/FDA-approved use: Steroid-responsive inflammatory conditions of the eye (e.g. allergic conjunctivitis, acne rosacea, superficial punctate keratitis, herpes zoster keratitis, iritis, cyclitis, and selected inflammatory conditions of the anterior segment of the globe) for which a corticosteroid is indicated and where superficial bacterial ocular infection or a risk of bacterial ocular infection exists.
• Guideline/clinical-practice supported use: Chronic anterior uveitis, and inflammation following ocular surgery, chemical or thermal burns, or removal of a corneal foreign body, when a bacterial infection risk is also present.

Dextrobac is intended for short-term, physician-supervised topical ophthalmic use only. It is not indicated for infections without an inflammatory component, and it is not a substitute for an antibiotic alone when no steroid-responsive inflammation is present.

Each formulation of Dexamethasone + Tobramycin combines two active ingredients in a topical ophthalmic base:

• Tobramycin 0.3% w/v - an aminoglycoside antibiotic.
• Dexamethasone 0.1% w/v (suspension) or 0.05%/0.1% depending on brand - a synthetic corticosteroid.

It is available as a sterile ophthalmic suspension (eye drops) and as an ophthalmic ointment, along with inactive/preservative ingredients such as benzalkonium chloride.

Dextrobac is a fixed-dose combination eye medication that pairs an aminoglycoside antibiotic (tobramycin) with a corticosteroid (dexamethasone). It is formulated as a sterile ophthalmic suspension (eye drops) or ointment for topical application to the eye.

The combination is designed for conditions where ocular inflammation needs to be controlled with a corticosteroid, while simultaneously covering or preventing susceptible bacterial infection with the antibiotic component. Dextrobac is available in Bangladesh from multiple manufacturers as eye drops (0.1%+0.3%) and eye ointment (0.1%+0.3%).

Dextrobac belongs to the therapeutic class of ophthalmic corticosteroid and antibiotic combination preparations, combining an aminoglycoside antibacterial (tobramycin) with a glucocorticoid anti-inflammatory agent (dexamethasone) for topical ocular use.

Dexamethasone + Tobramycin combines two complementary mechanisms of action:

• Tobramycin is an aminoglycoside antibiotic that binds irreversibly to the bacterial 30S ribosomal subunit, inhibiting bacterial protein synthesis and producing a bactericidal effect against many gram-negative and some gram-positive organisms commonly implicated in superficial ocular infections (e.g. Staphylococcus, Pseudomonas aeruginosa, Haemophilus influenzae).
• Dexamethasone is a potent synthetic glucocorticoid that suppresses the inflammatory response by inhibiting phospholipase A2, reducing edema, fibrin deposition, capillary dilation, leukocyte migration, and capillary and fibroblastic proliferation associated with inflammation.

Together, Dexamethasone + Tobramycin reduces ocular inflammation while providing antibacterial coverage against organisms susceptible to tobramycin, and topical absorption into the systemic circulation is generally low with normal use.

Dextrobac is administered topically into the conjunctival sac of the affected eye(s). Tilt the head back, pull down the lower eyelid to form a pocket, instill the drop or ointment without touching the tip to the eye or lashes, then close the eye gently for 1-2 minutes. Wash hands before and after application.

Formal drug-interaction studies with Dextrobac have not been conducted. Clinically relevant considerations include:

• Other topical ophthalmic products: When using more than one topical eye medication, separate applications by at least 5-10 minutes to prevent dilution or washout of either product.
• Other ototoxic/nephrotoxic aminoglycosides (systemic): Although systemic absorption from ophthalmic use is minimal, concurrent systemic aminoglycoside therapy should be noted by the treating physician.
• Other corticosteroid-containing ophthalmic products: Concurrent use may increase the risk of steroid-related ocular adverse effects (e.g. raised intraocular pressure); avoid combining unless directed by a physician.

Adverse effects reported with Dextrobac include:

• Common (local): Transient stinging or burning on instillation, eyelid itching, eyelid swelling, conjunctival hyperemia (redness), and blurred vision immediately after application.
• Steroid-related (with prolonged use): Elevated intraocular pressure/glaucoma, posterior subcapsular cataract formation, delayed wound/epithelial healing, and secondary ocular infection (bacterial, viral, or fungal) due to masking or potentiation of infection.
• Hypersensitivity reactions: Localized allergic reactions including lid itching, swelling, and conjunctival erythema (reported in a small proportion of patients).
• Uncommon: Mydriasis, ptosis, and optic nerve damage with long-term steroid exposure.

Report any unusual or persistent eye symptoms to a physician promptly.

Pregnancy: There are no adequate and well-controlled studies of Dextrobac in pregnant women. Topical ocular corticosteroids and aminoglycosides have limited systemic absorption; however, Dextrobac should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, and only under a physician's direction.

Lactation: It is not known whether topical ophthalmic administration of Dextrobac results in detectable levels in human milk. Caution should be exercised, and a physician should be consulted, when Dextrobac is administered to a nursing mother.

Dextrobac should be used with the following precautions:

• Intraocular pressure (IOP): Prolonged use (beyond 10 days) can result in raised IOP and/or glaucoma with optic nerve damage; IOP should be monitored regularly if treatment is extended.
• Cataract: Prolonged corticosteroid use may result in posterior subcapsular cataract formation.
• Delayed healing: Corticosteroids may slow corneal/scleral wound healing; use with caution after cataract surgery or in cases of thin cornea/sclera due to risk of perforation.
• Masking or worsening infection: Corticosteroid use may suppress the clinical signs of infection or prolong/exacerbate an existing viral or fungal ocular infection; prolonged use may also encourage secondary infection from organisms not susceptible to tobramycin, including fungal overgrowth.
• Not for injection or ingestion: Dextrobac is for topical ophthalmic use only.
• Antibiotic stewardship: Take exactly as prescribed by your physician; do not stop, extend, skip doses, or share this medicine with others without medical advice, in order to reduce the risk of antibiotic resistance and treatment failure.
• Contact lenses: Avoid wearing contact lenses during active infection or treatment.
• Driving/operating machinery: Transient blurred vision may occur after application; wait until vision clears before driving or operating machinery.

Topical ocular overdose of Dextrobac is unlikely to cause systemic toxicity, but excessive or prolonged use increases the risk of steroid-related ocular adverse effects (raised IOP, cataract, delayed healing). If accidental oral ingestion occurs, or if excessive instillation or a severe reaction is suspected, seek immediate medical attention or contact a poison control center/emergency services. Do not attempt unsupervised home treatment for a suspected overdose.

Store at room temperature (below 30°C, or as specified 2-25°C on the product label), away from light and moisture. Keep the container tightly closed and shake the suspension well before each use. Keep out of reach of children. Discard any remaining product after the course of treatment is completed or per the expiry/discard date on the label.

Pediatric use: Safety and effectiveness of Dextrobac in children below 2 years of age have not been established. Use in children 2 years and older should be under close physician supervision.

Geriatric use: No overall differences in safety or effectiveness have been observed between elderly and younger adult patients; no special dosage adjustment is required based on age alone.

Hepatic/renal impairment: Because systemic absorption of Dextrobac following topical ophthalmic use is minimal, no specific dosage adjustment is established for hepatic or renal impairment; use with routine physician supervision.

Treatment with Dextrobac should generally be limited to the shortest effective duration as determined by the treating physician, typically a few days to about 2 weeks. If improvement is not seen within a few days, or if treatment must continue beyond 10 days, intraocular pressure should be monitored due to the risk of steroid-induced glaucoma. Do not use for longer than prescribed.

Dexamethasone + Tobramycin belongs to the drug class of ophthalmic corticosteroid/antibiotic combinations, specifically pairing an aminoglycoside antibiotic (tobramycin) with a glucocorticoid corticosteroid (dexamethasone).

In Dexamethasone + Tobramycin, tobramycin acts by binding to the bacterial 30S ribosomal subunit, disrupting bacterial protein synthesis and causing bactericidal activity against susceptible organisms. Dexamethasone acts by inhibiting phospholipase A2 and downstream inflammatory mediators, reducing capillary permeability, leukocyte infiltration, and other components of the ocular inflammatory response.

Dextrobac is generally not recommended for children under 2 years of age, as safety and efficacy in this age group have not been established. In children 2 years and older, it may be used under a physician's direction with the same general dosing principles as adults, with close monitoring for local irritation and, in cases of prolonged use, intraocular pressure.