Tobramycin + Dexamethasone

Ophthalmic
Ocular inflammation with existing bacterial infection, Ocular inflammation with risk of bacterial infection

Hypersensitivity to tobramycin or dexamethasone. Viral infections of cornea and conjunctiva (e.g. epithelial herpes simplex keratitis [dendritic keratitis], vaccinia, varicella), mycobacterial eye infection, fungal diseases of ocular structure, untreated parasitic eye infection, untreated purulent eye infection, post-uncomplicated removal of foreign body.

Patients with hypersensitivity to other aminoglycoside antibiotics, known or suspected neuromuscular disorder (e.g. myasthenia gravis, Parkinson’s disease), glaucoma, history of ocular herpes simplex, diabetes. Children. Pregnancy and lactation.

Significant: Hypersensitivity reactions (e.g. erythema, pruritus, urticaria, skin rash, anaphylaxis, anaphylactoid or bullous reactions); secondary ocular infection (e.g. fungal infection), ocular hypertension or glaucoma, optic nerve injury, visual defects in acuity and field of vision, posterior subcapsular cataracts formation (prolonged use); central serous chorioretinopathy; overgrowth of non-susceptible organisms including fungi (prolonged use); slow corneal wound healing; cornea or scleral perforations (in diseases which thin the cornea or sclera).
Eye disorders: Eye pain, eye pruritus, ocular discomfort, conjunctival oedema, eye irritation, eye allergy, blurred vision, dry eye, ocular hyperaemia, mydriasis, increased lacrimation, foreign body sensation.
Gastrointestinal disorders: Dysgeusia.
Investigations: Increased intraocular pressure.
Nervous system disorders: Headache, dizziness.
Respiratory, thoracic and mediastinal disorders: Rhinorrhoea, laryngospasm.

Ophth: C

Wearing of contact lenses during treatment of eye infection or inflammation is not recommended. If the use of contact lenses is allowed by the physician, remove contact lenses before administration and reinsert after 15 minutes. This drug may cause temporary blurring of vision, if affected, do not drive or operate machinery.

Monitor intraocular pressure especially if used for >10 days and in patients with glaucoma; signs and symptoms of secondary infection. Examine the patient with the aid of magnification such as slit lamp biomicroscopy or fluorescein staining (if appropriate) before initial prescription and renewal of medication.

May increase risk for toxicity with systemic aminoglycosides.
Tobramycin: May be inactivated if used concomitantly with topical β-lactam antibiotic.
Dexamethasone: May increase the potential for corneal healing problems with topical NSAIDs. May increase risk of adrenal suppression or Cushing’s syndrome with CYP3A4 inhibitors (e.g. ritonavir and cobicistat).

Description: Tobramycin, an aminoglycoside antibiotic, inhibits bacterial protein synthesis by irreversibly binding to 30S ribosomal subunit resulting in abnormal bacterial cell membrane.
Dexamethasone inhibits the inflammatory response by suppressing the migration of neutrophil, decreasing the production of inflammatory mediators and reversing the increased capillary permeability. Additionally, it inhibits the normal immune response.
Pharmacokinetics:
Absorption: Tobramycin: Poorly absorbed across the cornea and conjunctiva. Time to reach peak concentration in the aqueous humour: 2 hours.
Dexamethasone: Absorbed into the eye. Time to reach maximum concentration in the cornea and aqueous humour: Within 1-2 hours.

Source: National Center for Biotechnology Information. PubChem Database. Tobramycin, CID=36294, https://pubchem.ncbi.nlm.nih.gov/compound/Tobramycin (accessed on Jan. 23, 2020)

Source: National Center for Biotechnology Information. PubChem Database. Dexamethasone, CID=5743, https://pubchem.ncbi.nlm.nih.gov/compound/Dexamethasone (accessed on Jan. 20, 2020)

Ophthalmic susp: Store below 30°C. Discard 4 weeks after opening. Ophthalmic ointment: Store below 25°C. Discard 4 weeks after opening. Storage recommendation may vary among countries or individual products or preparations. Refer to country- or product-specific recommendation.

Eye Antiseptics with Corticosteroids

S01CA01 - dexamethasone and antiinfectives ; Belongs to the class of corticosteroids in combination with antiinfectives. Used in the treatment of eye diseases.

Anon. Tobramycin and Dexamethasone. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 04/01/2021.

Dexamethasone; Tobramycin. Gold Standard Drug Database in ClinicalKey [online]. Elsevier Inc. https://www.clinicalkey.com/. Accessed 04/01/2020.

Novartis New Zealand Limited. Tobradex Ophthalmic Suspension and Ointment data sheet 23 July 2020. Medsafe. http://www.medsafe.govt.nz/. Accessed 04/01/2020.

Tobradex 3 mg/mL/1 mg/mL Eye Drops, Suspension (Novartis Pharmaceuticals UK Limited). MHRA. https://products.mhra.gov.uk/. Accessed 04/01/2021.

Tobradex Sterile Ophthalmic Suspension and Ointment (Novartis Corporation [Malaysia] Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my/. Accessed 04/01/2021.

Toradex (Alcon Laboratories, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 04/01/2020.

Toradex ST (Alcon Laboratories, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 04/01/2020.