Tobramycin

Description

Tobramycin ophthalmic solution USP, 0.3% is a sterile topical ophthalmic antibiotic formulation designed for the treatment of external ophthalmic infections. Each milliliter of the solution contains 3 mg of tobramycin (0.3%) as the active ingredient, along with inactive components including boric acid, sodium sulfate, sodium chloride, tyloxapol, and purified water. The pH of the solution is adjusted to a range of 7.0 to 8.0 using sodium hydroxide and/or sulfuric acid. Additionally, the formulation includes 0.1 mg (0.01%) of benzalkonium chloride as a preservative.

Tobramycin is classified as a water-soluble aminoglycoside antibiotic, exhibiting activity against a broad spectrum of gram-negative and gram-positive ophthalmic pathogens. The chemical structure of tobramycin is defined by the following chemical name: (2S,3R,4S,5S,6R)-4-amino-2-[(1S,2S,3R,4S,6R)-4,6-diamino-3-(2R,3R,5S,6R)-3-amino-6-(aminomethyl)-5-hydroxyoxan-2-yloxy-2-hydroxycyclohexyl]oxy-6-(hydroxymethyl)oxane-3,5-diol.

Uses and Indications

Tobramycin ophthalmic solution, 0.3%, is indicated for the treatment of external infections of the eye and its adnexa caused by susceptible bacteria. This topical antibiotic is effective in managing bacterial infections in the ocular region.

Appropriate monitoring of bacterial response to topical antibiotic therapy should accompany the use of tobramycin ophthalmic solution to ensure therapeutic efficacy and safety.

Clinical studies have demonstrated that tobramycin is safe and effective for use in pediatric patients, supporting its application in children with indicated conditions.

Dosage and Administration

In cases of mild to moderate disease, the recommended dosage is to instill 1 or 2 drops into the affected eye(s) every 4 hours. For severe infections, the dosage is increased to 2 drops instilled into the eye(s) hourly until clinical improvement is observed. Following improvement, the frequency of administration should be gradually reduced before discontinuation of treatment.

This medication is intended for topical ophthalmic use only.

Contraindications

Tobramycin ophthalmic solution, 0.3% is contraindicated in patients with known hypersensitivity to any of its components.

Additionally, the use of this product is not recommended in patients who exhibit signs and symptoms of bacterial ocular infection while wearing contact lenses.

Warnings and Precautions

Topical ophthalmic use is the sole intended application for this product; it is strictly contraindicated for injection into the eye.

Patients may exhibit sensitivity to topically applied aminoglycosides, which can manifest in varying degrees of hypersensitivity reactions. These reactions may range from localized effects to more severe systemic responses, including erythema, itching, urticaria, skin rash, anaphylaxis, anaphylactoid reactions, or bullous reactions. In the event of a sensitivity reaction to tobramycin ophthalmic solution, 0.3%, it is imperative to discontinue use immediately.

Prolonged use of this antibiotic preparation may lead to the overgrowth of nonsusceptible organisms, including fungi. Should a superinfection occur, it is essential to initiate appropriate therapy without delay.

Cross-sensitivity to other aminoglycoside antibiotics is a possibility. If hypersensitivity develops while using this product, it is crucial to discontinue use and implement suitable therapeutic measures.

Patients should be counseled against wearing contact lenses if they exhibit signs and symptoms of a bacterial ocular infection, as this may exacerbate their condition.

Side Effects

The most frequent adverse reactions associated with tobramycin ophthalmic solution, 0.3%, include hypersensitivity and localized ocular toxicity, which encompasses lid itching and swelling as well as conjunctival erythema. These reactions are reported to occur in less than three out of 100 patients treated with the solution.

In addition to the common adverse reactions, postmarketing experience has identified further adverse reactions, including anaphylactic reactions, Stevens-Johnson syndrome, and erythema multiforme.

It is important to note that additional adverse reactions have been reported with systemic aminoglycosides, which may include neurotoxicity, ototoxicity, and nephrotoxicity. Furthermore, aminoglycosides may exacerbate muscle weakness in patients with known or suspected neuromuscular disorders, such as myasthenia gravis and Parkinson’s disease.

Patients may also experience sensitivity to topically applied aminoglycosides, with the severity of hypersensitivity reactions varying from localized effects to more generalized reactions. These reactions can include erythema, itching, urticaria, skin rash, anaphylaxis, anaphylactoid reactions, and bullous reactions. In the event of a sensitivity reaction to tobramycin ophthalmic solution, 0.3%, it is advised to discontinue use.

Drug Interactions

Cross-sensitivity to other aminoglycoside antibiotics may occur. In the event that hypersensitivity develops with this product, it is advised to discontinue use and initiate appropriate therapy.

No specific drug or laboratory test interactions have been identified in the available data.

Packaging & NDC

The table below lists all NDC Code configurations of Tobramycin, the U.S. brand-name prescription product. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

Safety and effectiveness in pediatric patients below the age of 2 months have not been established. Therefore, caution is advised when considering treatment in this age group.

Geriatric Use

Elderly patients, defined as those aged 65 years and older, have not demonstrated any overall differences in safety or effectiveness compared to younger patients. Therefore, no specific dosage adjustments are necessary for this population based on age alone.

However, healthcare providers should remain vigilant in monitoring geriatric patients for any potential age-related changes that may affect drug metabolism and response. It is essential to consider individual patient factors, including comorbidities and concurrent medications, when prescribing to elderly patients to ensure optimal therapeutic outcomes.

Pregnancy

Reproduction studies in three types of animals at doses up to 33 times the normal human systemic dose have revealed no evidence of impaired fertility or harm to the fetus due to tobramycin. However, there are no adequate and well-controlled studies in pregnant women. Because animal studies are not always predictive of human response, tobramycin should be used during pregnancy only if clearly needed. Healthcare professionals are advised to weigh the potential benefits against the risks when considering the use of this drug in pregnant patients.

Lactation

Because of the potential for adverse reactions in nursing infants from tobramycin ophthalmic solution, a decision should be made whether to discontinue nursing the infant or discontinue the drug, taking into account the importance of the drug to the mother.

Renal Impairment

Patients with renal impairment have not been specifically addressed in the available prescribing information. There are no dosage adjustments, special monitoring requirements, or safety considerations outlined for individuals with reduced kidney function. Healthcare professionals should exercise caution and consider the lack of data when prescribing to this patient population.

Hepatic Impairment

Patients with hepatic impairment have not been specifically studied in relation to the use of this medication. Consequently, there are no established dosage adjustments, special monitoring requirements, or precautions for individuals with compromised liver function. It is recommended that healthcare providers exercise caution when prescribing this medication to patients with hepatic impairment, given the lack of data on its safety and efficacy in this population. Regular monitoring of liver function may be warranted based on clinical judgment.

Overdosage

In the absence of specific information regarding overdosage, healthcare professionals are advised to exercise caution and adhere to general principles of management in cases of suspected overdose.

It is essential to monitor the patient closely for any potential symptoms that may arise from an overdose. Symptoms can vary widely depending on the substance involved and the individual patient's response.

In the event of an overdose, the following management procedures are recommended:

1. Assessment: Conduct a thorough assessment of the patient's clinical status, including vital signs and level of consciousness.

2. Supportive Care: Provide supportive care as necessary, which may include airway management, oxygen supplementation, and intravenous fluids.

3. Consultation: Consider consulting a poison control center or a medical toxicologist for guidance on specific interventions and treatments that may be appropriate based on the substance involved.

4. Documentation: Document all findings, interventions, and the patient's response to treatment meticulously.

Healthcare professionals should remain vigilant and prepared to implement these general management strategies in the event of an overdose, even in the absence of specific overdosage information.

Nonclinical Toxicology

Reproduction studies conducted in three animal species at doses up to 33 times the normal human systemic dose have demonstrated no evidence of impaired fertility or teratogenic effects associated with tobramycin. However, it is important to note that there are no adequate and well-controlled studies in pregnant women. Given that animal studies may not always accurately predict human responses, the use of this drug during pregnancy should be considered only when clearly necessary.

Postmarketing Experience

Postmarketing experience has identified additional adverse reactions associated with the use of the product. Reports include anaphylactic reactions, Stevens-Johnson syndrome, and erythema multiforme.

Furthermore, systemic aminoglycosides have been associated with neurotoxicity, ototoxicity, and nephrotoxicity in patients undergoing treatment. It has also been noted that aminoglycosides may exacerbate muscle weakness in individuals with known or suspected neuromuscular disorders, such as myasthenia gravis or Parkinson’s disease, due to their potential impact on neuromuscular function.

Patient Counseling

Healthcare providers should advise patients to avoid touching the dropper tip to any surface, as this may lead to contamination of the solution. It is important to inform patients that they should not wear contact lenses if they experience any signs or symptoms of a bacterial ocular infection.

In the event that a patient experiences a sensitivity reaction to tobramycin ophthalmic solution, 0.3%, they should be instructed to discontinue use immediately. Additionally, if a superinfection occurs, appropriate therapy should be initiated without delay.

Healthcare providers should discuss with patients the need to make a decision regarding breastfeeding. This decision should consider whether to discontinue nursing the infant or to discontinue the drug, weighing the importance of the medication to the mother against the potential risks to the infant.

Storage and Handling

Tobramycin ophthalmic solution USP, 0.3% is supplied in a container that allows for easy application. It should be stored at a temperature range of 2°C to 25°C (36°F to 77°F). Care should be taken to avoid exposure to excessive heat, which may compromise the integrity of the product.

Once opened, the solution can be used until the expiration date indicated on the bottle. Proper storage and handling are essential to maintain the efficacy and safety of the product throughout its use.

Additional Clinical Information

Patients should be counseled to avoid touching the dropper tip to any surface to prevent contamination of the solution. Additionally, it is advised that patients refrain from wearing contact lenses if they exhibit signs and symptoms of a bacterial ocular infection.

Postmarketing experience has revealed additional adverse reactions, including anaphylactic reactions, Stevens-Johnson syndrome, and erythema multiforme. Furthermore, neurotoxicity, ototoxicity, and nephrotoxicity have been reported in patients undergoing systemic aminoglycoside therapy. Clinicians should be aware that aminoglycosides may exacerbate muscle weakness in patients with known or suspected neuromuscular disorders, such as myasthenia gravis or Parkinson’s disease, due to their potential impact on neuromuscular function.

FDA Insert (PDF)

This document is the official FDA-approved prescribing information for Tobramycin as submitted by Bausch & Lomb Incorporated. It includes detailed information about indications, dosage, contraindications, warnings, and clinical pharmacology.

View full prescribing information (PDF)