Tobramycin/ Dexamethasone

Registered South African indications:

• Reduction of ocular inflammation and prophylaxis of infection due to susceptible organisms following intraocular surgery

Contraindications

Registered South African contraindications

• Hypersensitivity to tobramycin, dexamethasone, or any of the ingredients of this combination product
• Epithelial herpes simplex keratitis (dendritic keratitis), vaccinia, varicella, and many other viral diseases of the cornea and conjunctiva
• Mycobacterial infection of the eye
• Fungal diseases of ocular structures, or untreated parasitic eye infections
• Untreated purulent infection of the eye
• Use is always contraindicated after uncomplicated removal of a corneal foreign body
• Should not be used in the treatment of mechanical lacerations and abrasions of the eye, as it will delay healing and promote the development and spread of infection

Contraindications registered in other jurisdictions

• Hypersensitivity to tobramycin or dexamethasone or to any of the excipients in this combination product
• Herpes simplex keratitis
• Vaccinia, varicella and other viral disease of the cornea and conjunctiva
• Mycobacterial infections of the eye caused by, but not limited to, acid-fast bacilli such as Mycobacterium tuberculosis, Mycobacterium leprae, or Mycobacterium avium
• Fungal diseases of ocular structures or untreated parasitic eye infections
• Untreated purulent infection of the eye

Cautions

• Pregnancy
• Breastfeeding
• Renal impairment
• Hepatic impairment
• Prolonged use
• Children
• Diabetes mellitus
• Patients predisposed to raised intraocular pressure
• Diseases causing thinning of the cornea or sclera
• Concomitant use of soft contact lenses

Forms avail. in SA and covered in this monograph: eyo, opd

South African registered indications and dosages

Reduction of ocular inflammation and prophylaxis of infection due to susceptible organisms following intraocular surgery

Tobramycin/ Dexamethasone
3/1 (mg/ml)

Pre-operative

• Ophthalmic (opd): Instil 1 drop into the operative eye, 4hrly while awake for 3 days; Then: Instil 1 drop into the operative eye upon conclusion of surgery
• Ophthalmic (eyo): Apply approx. a 1.5cm ribbon ointment strip into the operative eye 3 times a day, 3 days prior to surgery; Then: Apply a 1.5cm ribbon ointment strip into the eye immediately upon conclusion of surgery

Post-operative

• Ophthalmic (opd): Day 1: Beginning at the first dressing change, instil 2 drops, 2hrly while awake for 2 days; Then: Day 3: Instil 1 drop into the eye 4 times dly for 1 week; Maintenance: Thereafter, instil 1 drop/day for 10 days
• Ophthalmic (eyo): Day 1: Beginning at the first dressing change, apply a 1.5cm ribbon ointment strip 3 times dly for the first 9 days following surgery; Maintenance: From day 10, apply a 1.5cm ribbon ointment strip/day until day 20

Eye drops: Not more than 20ml should be prescribed initially, and the prescription should not be repeated without further evaluation

Eye ointment: Not more than 7g should be prescribed initially, and the prescription should not be refilled without further evaluation

Shake eye drops well before use and store upright. When removing the cap for the first time, remove and discard the tamper-evident ring to prevent the ring from falling into the patient’s eye

Tobramycin/ dexamethasone is for ocular use only. If more than one topical ophthalmic medicine is being used, the medicines must be administered at least 5 minutes apart. Eye ointments should be administered last

No specific recommendations provided

The safety and efficacy of tobramycin/ dexamethasone in children have been established by reported broad clinical experience, but only limited data are available. In a reported study, differences in the safety profile between adult and paediatric patients were not observed

Pregnancy

• Caution; not recommended
• There are no or limited amount of data from the topical ocular use of tobramycin and dexamethasone in pregnant women. Tobramycin does cross the placenta into the foetus after intravenous dosing in pregnant women. Tobramycin is not expected to cause ototoxicity from in utero exposure. Prolonged or repeated corticoid use during pregnancy has been associated with an increased risk of intrauterine growth retardation. Infants born of mothers who have received substantial doses of corticosteroids during pregnancy should be observed carefully for signs of hypoadrenalism
• Studies in animals have shown reproductive toxicity after systemic administration of tobramycin and dexamethasone. These effects were observed at exposures considered sufficiently in excess of the maximum human ocular dosage delivered from the maternal use of the combination product. Tobramycin/ dexamethasone is not recommended during pregnancy

Breastfeeding

• Caution; not recommended
• Tobramycin is excreted in human milk after systemic administration. No data is available on the passage of dexamethasone into human breast milk. It is unknown whether tobramycin and dexamethasone are excreted in human milk following topical ocular administration. It is not likely that the amount of tobramycin and dexamethasone would be detectable in human milk or be capable of producing clinical effects in the infant following topical use of tobramycin/ dexamethasone
• A risk to the breastfeeding child cannot be excluded. A decision must be made whether to discontinue breastfeeding or to discontinue/ abstain from therapy taking into account the benefit of breastfeeding for the child and the benefit of therapy for the woman

Fertility

• Studies have not been performed to evaluate the effect of tobramycin on human or animal fertility. There is limited clinical data to evaluate the effect of dexamethasone on male or female fertility

Renal Impairment

• Caution; no information available

Hepatic Impairment

• Caution; no information available

Elderly

• No dose adjustment recommended

Porphyria Information

• Probably not porphyrinogenic (PNP)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Headache
• Dizziness

Respiratory Disorders

• Rhinorrhoea
• Laryngospasm
• Post-nasal drip

Gastrointestinal Disorders

• Dysgeusia
• Nausea
• Abdominal discomfort

Skin and Subcutaneous Tissue Disorders

• Rash
• Swollen face 
• Pruritis

Immune, Blood and Lymphatic System Disorders

• Hypersensitivity

Sensory Disorders

• Eye pruritis
• Ocular discomfort
• Ocular hypertension
• Conjunctival oedema
• Increased intraocular pressure
• Keratitis
• Eye allergy
• Blurred vision
• Dry eye
• Ocular hyperaemia
• Eyelid oedema
• Erythema of the eyelid
• Mydriasis
• Increased lacrimation

• Topical steroids
• Topical non-steroidal anti-inflammatory drugs

None routine

Tobramycin
Interferes with bacterial protein synthesis by binding to 30S ribosomal subunit resulting in a defective bacterial cell membrane. 

Dexamethasone
Suppresses inflammation by inhibiting oedema, fibrin deposition, capillary leakage, and phagocytic migration during the inflammatory response. Glucocorticoids inhibit vascular endothelial growth factor, a potent promoter of vascular permeability.

COMBINATION PREPARATIONS

Tobramycin/ Dexamethasone

Eye drops (per ml) 3mg/1mg

• Tobradex (Novartis South Africa) originator

Eye ointment (per g) 3mg/1mg

• Tobradex (Novartis South Africa) originator