TobraDex (Tobramycin + Dexamethasone): what it is, how it is used and how it works

Index

  • Introduction: what is it?
  • Dosage: how is it used and how does it work?
  • Warnings and Precautions
  • Interactions and side effects
  • Pregnancy and breastfeeding
  • Note

Questions and answers

Introduction: what is it?

The Tobradex is a combination of an antibiotic and a corticosteroid indicated for the treatment of eye inflammations or conducted outside the middle-ear and ear when it is needed a therapy with a corticosteroid in the presence of an infection caused by bacteria susceptible to tobramycin and when there is a risk of an infection . TobraDex contains two active ingredients : tobramycin , an aminoglycoside antibiotic , and dexamethasone , a corticosteroid .

Tobramycin has an antibacterial activity and toxicity profile very similar to that of gentamicin . However, it has superior activity against Pseudomonas aeruginosa , making it the preferred aminoglycoside antibiotic for the treatment of serious infections whose cause, known or suspected, is attributable to this microorganism. Tobramycin is ineffective against mycobacteria.

TobraDex is available in ear drops , or as eye drops or ophthalmic ointment. All these pharmaceutical forms contain the same composition of active ingredients (0.3% tobramycin and 0.1% dexamethasone) which correspond to 3 mg of tobramycin and 1 mg of dexamethasone per mL (eye drops and ear drops) or per mg (ophthalmic ointment).

TobraDex can be prescribed with RR Recipe – prescription medicines .

Dosage: how is it used and how does it work?

  • TobraDex as ear drops should be instilled into the external ear canal, four drops three times a day or as directed by your doctor. The maximum duration of treatment must not exceed 7 days ;
  • Eye drops : instill 1 or 2 drops 4-5 times a day according to medical prescription;
  • Ointment : apply a small amount (about 1 cm of ointment) in the conjunctival sac 3-4 times a day according to medical prescription. The duration of treatment must be determined by the doctor . The ointment can be used instead of eye drops in the evening before bedtime.
    To limit the amount of medicine that passes into the blood after application to the eyes, keep the eyelid closed and at the same time apply gentle pressure with a finger on the inner corner of the eye near the nose for at least 2 minutes.

If you are using other eye drops or ophthalmic ointments, allow at least 5 minutes between instillation of each medicine .
The ophthalmic ointment should be used last.

The Tobramycin is an aminoglycoside antibiotic that acts by inhibiting bacterial growth through the ‘ inhibition of protein synthesis in the microorganism . The action takes place at the level of ribosomes , which are intracellular structures responsible for the process of synthesis of proteins essential for normal cell growth.

The dexamethasone is one of the most potent corticosteroid hormones. The corticosteroidsthey act by interacting with specific receptors present on target tissues and are able to regulate the expression of some genes sensitive to these hormones. This leads to a change in the levels and types of proteins that are expressed in target tissues.
Most of the effects of corticosteroids do not you immediate , but it manifests itself after several hours of treatment. Topical corticosteroids exert an anti-inflammatory action and their use is well known. They suppress some aspects of the inflammatory process , such as edema , fibrin deposition , dilation of the capillaries, leukocyte migration, capillary proliferation, collagen deposition, scar formation and fibroblast proliferation. Topical corticosteroids are effective in acute inflammatory conditions of the conjunctiva, sclera, cornea, eyelid, iris and anterior segment of the globe , as well as in conditions of ocular allergy .

Of fundamental importance with regard to local therapy is the fact that dexamethasone is over 2000 times more soluble than hydrocortisone and prednisolone . The exact mechanism of the anti-inflammatory action of dexamethasone is not known. It inhibits the production of multiple inflammatory cytokines and causes numerous glucocorticoid and mineralocorticoid-like effects.
Corticosteroids suppress the inflammatory response to numerous agents and therefore can delay or slow wound healing. Because corticosteroids can inhibit the body’s defense mechanism against infection , when this inhibition is considered clinically significant, an antimicrobial drug can be used concomitantly .
How does the eye and vision work?

Warnings and Precautions

Carefully follow the directions of your doctor or pharmacist regarding the dosage and frequency of administration. Use the product for the shortest time necessary to resolve the problem.
Any of the undesirable effects described for systemic corticosteroids, including hypoadrenalism , can also occur with topically administered corticosteroids.
Use the precautions related to the use of steroids, avoid prolonged use of the product.

The use of tobramycin may cause ototoxicity and the patient should inform the physician of symptoms such as dizziness, vertigo , tinnitus and decreased hearing.following the instillation of TobraDex.
The use of this drug is contraindicated in patients with hypersensitivity to the components or to other closely related substances from a chemical point of view.

TobraDex ear drops should not be used in children under 2 years of age , in patients with cutaneous tuberculosis, Herpes simplex , viral disease with skin localization, mycosis of the ear , in cases of known or suspected perforation of the tympanic membrane , while breastfeeding .

TobraDex eye drops or ophthalmic ointment are contraindicated and should not be used bypatients with Herpes Simplex keratitis , smallpox vaccine, chicken pox or other viral infections of the cornea and conjunctiva, mycosis of the eye or parasitic infections of the eye untreated, mycobacterial eye infections (tuberculosis of the eye), intraocular hypertension, purulent ophthalmias acute, purulent conjunctivitis and purulent and herpetic blepharitis which can be masked or aggravated by corticosteroids, sty.

Due to the characteristics of this medicine, no toxic effects are expected to develop following an ophthalmic overdose or in the event of accidental ingestion of a whole bottle of eye drops or a tube of ointment. However, excessive and too prolonged use of the drug,it can lead to the appearance of resistance by bacteria to the action of tobramycin , as also occurs with all other compounds with antibacterial action.
The resistance to tobramycin is spread through several mechanisms which include:

  • Alterations of some subunits present in the ribosomes of the bacterial cell which are the target of the antibiotic;
  • Interference with tobramycin transport within the cell which therefore no longer reaches its site of action;
  • Inactivation of tobramycin by a set of enzymes capable of modifying the chemical structure of the antibiotic.

These mechanisms can be passed on to other bacteria and cross-resistance with other aminoglycosides can occur . Sensitization (allergic reaction) to aminoglycoside antibiotics such as tobramycin, given into the eye,
may occur in some patients . This allergic reaction can range from localized itching or redness of the skin, to severe general allergic reactions (anaphylactic reactions) or severe skin reactions. If these symptoms occur while using TobraDex eye drops or ophthalmic ointment, it is advisable to discontinue treatment.and contact your doctor. This allergic sensitivity can also occur with other antibiotics belonging to the same class of aminoglycosides, administered both in the eye and systemically (by injection).
Cross-hypersensitivity to other aminoglycosides may occur, therefore the possibility that patients sensitized to topically administered tobramycin may also be sensitive to other topically and / or systemically administered aminoglycosides should be considered. In case the topical administration of tobramycin is accompanied by systemic treatment with aminoglycoside antibiotics, the total serum concentration should be carefully monitored .

As with all antibiotics, prolonged use can promotegrowth of resistant germs including fungi ; if no clinical improvement is observed in a reasonable period of time, use of the product should be discontinued and the doctor should be consulted .

L ‘ application of corticosteroids in the eye for a long period of time can cause an increase in pressure in the eye (including an illness called glaucoma, with damage to the optic nerve ), vision problems and the formation of cataracts ( opacification of the lens inside this of the eye, called crystalline ).

If you use TobraDex eye drops or ophthalmic ointment for a long time,check pressure in the eyes regularly and frequently. This is particularly important in children , as the risk of increased pressure in the eyes from corticosteroids may be greater in children under the age of six and may occur earlier than it occurs in adults. Seek advice from your doctor, especially if you need to use Tobradex eye drops or ophthalmic ointment in children.

The risk of corticosteroid-induced increase in eye pressure and / or cataract formation is greater in predisposed patients (e.g. diabetic patients). Visual disturbances may be reported with the use of systemic and topical corticosteroids. If a patient presents with symptoms such as blurred vision or other visual disturbances, a visit by an ophthalmologist should be considered for evaluation of possible causes which may include cataracts, glaucoma or rare diseases such as central serous chorioretinopathy (CSCR) , which have been reported after use of systemic and topical corticosteroids.

Corticosteroids applied to the eye can slow down the healing of corneal wounds . It is also known that NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) applied in the eye to slow or delay healing. The concomitant applicationof NSAIDs and corticosteroids in the eye can potentially increase eye wound healing problems .

Do not wear contact lenses when treating an eye inflammation or infection. If your doctor still allows you to wear contact lenses, you should remove them before applying TobraDex eye drops and wait at least 15 minutes after instillating the dose before reapplying them.

A more careful control doctor is required in elderly patients , in patients already being treated with aminoglycoside antibiotics or with impaired renal function and patients on concomitant treatment with certain diuretics. If in doubt, consult your doctor.

  • In case of irritation or sensitization related to the use of the product, stop the treatment;
  • The product should not be applied to wounds and burns;
  • The ear canal must be cleaned before applying the drops. To be used under direct medical supervision;
  • The product must not be injected .

Any of the undesirable effects described for systemic corticosteroids, including hypoadrenalism , can also occur with topical corticosteroids, especially in pediatric patients. Pediatric patients may be more sensitive than adults to the effects of exogenous corticosteroids and in particular to depression of the hypothalamus-pituitary-adrenal axis induced by topical corticosteroids. Depression of the hypothalamic-pituitary-adrenal axis, Cushing’s syndrome , growth retardation and weight loss and intracranial hypertension have been described
in children treated with topical cortisone.. In children, manifestations of secondary hypoadrenalism include low cortisol levels and failure to respond to ACTH stimulation. Manifestations of intracranial hypertension include tension of the fontanels , headache, and bilateral papilledema .

TobraDex does not affect or only transiently affects the ability to drive and use machines. However, the transient blurring of visionor other visual disturbances may affect the ability to drive and use machines. If blurred vision occurs after instillation, the patient should wait for the vision to clear before driving and operating machinery.

The bottle must be shaken well before use to ensure a uniform suspension of the active ingredient.

Check out the best facilities for eye examination:
The best hospitals for eye examination

Interactions and side effects

As a general guideline for personal safety, you should tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. Tell your doctor especially if you are taking other eye medicines that contain drugs belonging to the class of NSAIDs (Non-Steroidal Anti-Inflammatory Drugs). Concomitant application of NSAIDs and corticosteroids in the eye can potentially increase corneal wound healing problems.
Contact your doctor if you are taking ritonavir or cobicistat , as they can increase the level of dexamethasone in your blood .
No clinically relevant interactions have been described with topical auricular administration of tobramycin.

Regarding the safety or efficacy of TobraDex, no differences were observed between the effects in adults and pediatric or elderly patients .
TobraDex® eye drops and TobraDex® ointment can be used in children from two years of age onwards at the same doses as for adults. Safety and efficacy in children aged less than two years have not been established and no data are available. Ototoxicity

reactions have occurred following topical administration (ear drops) of aminoglycosides, although it is not possible to estimate an exact incidence of the adverse reaction.
Prolonged use of topical ophthalmic corticosteroids (eye drops and ophthalmic ointment) can cause increased intraocular pressure with possible damage to the optic nerve , decreased visual acuity and visual field defects, subcapsular cataract formation and delayed healing. of wounds. The corticosteroid could cause a thinning of the cornea or sclera with a possible increased risk of perforation, especially with prolonged treatment.
Following the use of combinations containing corticosteroids and antimicrobials, the development of secondary infections has occurred. Long-term application of corticosteroids can facilitate the development of corneal fungal infections.

Serious adverse reactions such as neurotoxicity , ototoxicity and nephrotoxicity have occurred in patients treated with systemic tobramycin . Sensitization to topically administered aminoglycoside antibiotics may occur in some patients with cases of hypersensitivity.

Overdose
Excessive or prolonged use of topical corticosteroids can depress pituitary-adrenal function, causing secondary hypoadrenalism and manifestations of hypercorticism including Cushing’s syndrome, in particular asthenia , adynamia , arterial hypertension , heart rhythm disturbances, hypokalaemia , metabolic alkalosis .
TobraDex contains benzalkonium chloride , an irritant which can cause local skin reactions .
The TobraDex eye drops contains the thiloxapol component(a liquid polymer used as a surfactant to improve surface wettability and miscibility of liquid drug components) which is chemically incompatible with tetracycline .

Pregnancy and breastfeeding

Fertility
No studies have been performed to evaluate the effect on human fertility of topical aural administration of TobraDex.

Pregnancy
There are no or limited data from the topical auricular use of tobramycin or dexamethasone in pregnant women.
TobraDex should only be used in pregnancy if the doctor considers that the expected benefit to the mother justifies the potential risk to the fetus .

Breastfeeding
The use of TobraDex is contraindicated during breastfeeding. Corticosteroids and tobramycin are excreted in breast milk after systemic administration. It is currently unknown whether tobramycin or topical auricular dexamethasone are excreted in human milk. However, the risk to infants cannot be excluded.

Consult the centers that have declared to be specialized in Pediatric Otolaryngology:
Centers specialized in Pediatric Otolaryngology

Notes (methods of storage, validity, disposal)

The ear drops, eye drops and ointment are valid for 2 years .
The container must not be stored at a temperature above 25 ° C and must not be frozen. Use the product within 30 days of first opening the container (28 days in the case of the ointment).
Unused medicine and waste derived from this medicine must be disposed of in accordance with local regulations.

Questions and answers

WHAT IS TOBRADEX USED FOR?

In TobraDex it is a combination of an antibiotic and a corticosteroid indicated for the treatment of inflammation of the eye or external ear canal and middle ear when anti-inflammatory therapy with a corticosteroid is required in the presence of an infection caused by bacteria sensitive to tobramycin .

HOW LONG CAN TOBRADEX BE USED?

As with all drugs, it is advisable to carefully follow the instructions of the doctor or pharmacist regarding the dosage and frequency of administration, and use the product for the shortest time necessary to resolve the problem.
In the case of ear drops, the maximum duration of treatment should not exceed 7 days .

IS TOBRADEX AN ANTIBIOTIC?

TobraDex is a combination of an aminoglycoside antibiotic (tobramycin) and a corticosteroid (dexamethasone) . It therefore combines the antibacterial action of tobramycin with the anti-inflammatory action of dexamethasone.

WHAT ARE THE DIFFERENCES BETWEEN TOBRADEX AND TOBRAL?

Tobral and Tobradex both contain an antibiotic (tobramycin), while Tobradex alone also contains a cortisone (dexamethasone).
Tobral is indicated in adults and children from one year of age onwards for the treatment of infections of the eye and adnexa caused by bacteria sensitive to tobramycin: acute, subacute and chronic catarrhal conjunctivitis; blepharitis; bacterial keratitis; dacryocystitis; pre and post-operative prophylaxis in interventions on the anterior segment of the eye.
TobraDex is used instead in case of ocular inflammation, when the presence of an anti-inflammatory drug such as dexamethasone is also necessary and when there is an eye infection or the risk of contracting it in adults.

 

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