Tobramycin dexamethasone - ophthalmic


Generic Medicine Info
Indications and Dosage
Ophthalmic
Ocular inflammation with suspected or confirmed bacterial infection
Adult: Available preparations:
Tobramycin 3 mg and dexamethasone 1 mg per mL of eye drop susp
Tobramycin 3 mg and dexamethasone 0.5 mg per mL of eye drop susp
Tobramycin 3 mg and dexamethasone 1 mg per gram of eye ointment

As eye drop susp: Instil 1-2 drops into the conjunctival sac(s) of the affected eye(s) 4-6 hourly; may increase to 1-2 drops 2 hourly during the initial 24-48 hours then gradually decrease the frequency as signs and symptoms improve. As eye ointment: Apply a small amount (approx half an inch ribbon) into the conjunctival sac(s) of the affected eye(s) up to 3-4 times daily.
Child: ≥2 years Same as adult dose. Dosage recommendations may vary among countries or individual products. Refer to specific product guidelines.
Contraindications
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.
Special Precautions
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.
Adverse Reactions
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.
Patient Counseling Information
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.
MonitoringParameters
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.
Drug Interactions
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).
Action
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.
Chemical Structure

Chemical Structure Image
Tobramycin

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


Chemical Structure Image

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

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

Disclaimer: This information is independently developed by MIMS based on Tobramycin + Dexamethasone from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by MIMS.com
  • Duocom
  • Mydexin
  • Mytodex
  • Orbidex T
  • Ramtrex
  • Rapidex
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Sign up for free
Already a member? Sign in