Tobramycin

Description

Tobramycin ophthalmic solution USP, 0.3% is a sterile topical ophthalmic antibiotic formulation. Each mL of this solution contains tobramycin as the active ingredient at a concentration of 0.3% (3 mg). The formulation includes benzalkonium chloride as a preservative at 0.01% (0.1 mg). Inactive ingredients consist of boric acid, sodium sulfate decahydrate, sodium chloride, tyloxapol, sodium hydroxide and/or sulfuric acid (to adjust pH), and water for injection. The pH of the solution ranges from 7.0 to 8.0, with an osmolality of 260-320 mOsm/kg. Tobramycin is classified as a water-soluble aminoglycoside antibiotic, with a molecular weight of 467.52 g/mol and a molecular formula of C18H37N5O9. Its chemical name is O-3-Amino-3-deoxy-α-D-glucopyranosyl-(1→4)-O-2,6-diamino-2,3,6-trideoxy-α-D-ribo-hexopyranosyl-(1→6)-2-deoxy-L-streptamine.

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 and is supported by clinical studies demonstrating its safety and efficacy in pediatric populations.

Appropriate monitoring of bacterial response to topical antibiotic therapy should accompany the use of tobramycin ophthalmic solution 0.3% to ensure optimal therapeutic outcomes.

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.

Contraindications

Tobramycin ophthalmic solution 0.3% is contraindicated in patients with a known hypersensitivity to any of its components. Use in these patients may lead to severe allergic reactions.

Warnings and Precautions

Topical ophthalmic medications are intended solely for external application to the eye and must not be injected. It is imperative that healthcare professionals ensure that patients understand this critical usage guideline to prevent serious complications.

Patients may exhibit sensitivity to aminoglycosides when applied topically. The spectrum of hypersensitivity reactions can range from localized effects to more severe systemic responses. These reactions may include, but are not limited to, erythema, itching, urticaria, skin rash, and in rare cases, anaphylaxis or anaphylactoid reactions, as well as bullous reactions.

In the event that a patient experiences any signs of sensitivity or hypersensitivity to tobramycin ophthalmic solution 0.3%, it is essential to discontinue use immediately and consider alternative therapeutic options. Monitoring for these reactions is advised to ensure patient safety and to facilitate timely intervention if necessary.

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 systemic aminoglycosides have been associated with additional adverse reactions such as neurotoxicity, ototoxicity, and nephrotoxicity. Furthermore, aminoglycosides may exacerbate muscle weakness in patients with known or suspected neuromuscular disorders, including myasthenia gravis and Parkinson’s disease.

Patients should be aware that sensitivity to topically applied aminoglycosides may occur, with the severity of hypersensitivity reactions ranging from local effects to more generalized reactions. These may include erythema, itching, urticaria, skin rash, and in severe cases, anaphylaxis or anaphylactoid reactions, including bullous reactions. If a sensitivity reaction to tobramycin ophthalmic solution 0.3% occurs, it is advised to discontinue use immediately.

Drug Interactions

There are currently no documented drug interactions associated with the use of this medication. Additionally, there is no information available regarding interactions with laboratory tests. As such, no specific recommendations for dosage adjustments or monitoring are warranted at this time.

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. Clinical studies have demonstrated that tobramycin is safe and effective for use in children.

Geriatric Use

Elderly patients may not exhibit overall differences in safety or effectiveness compared to younger patients when treated with this medication. However, it is essential for healthcare providers to remain vigilant in monitoring geriatric patients due to the potential for altered pharmacokinetics and increased sensitivity to medications in this population.

While no specific dosage adjustments are mandated based on age alone, clinicians should consider individual patient factors, including comorbidities and concurrent medications, when determining the appropriate treatment regimen for elderly patients. Regular assessment and monitoring are recommended to ensure optimal therapeutic outcomes and to mitigate any potential risks associated with treatment in this demographic.

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 outlined 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 prudent in these cases, although specific parameters are not defined in the available information.

Overdosage

There is currently no specific information available regarding overdosage for this medication. Healthcare professionals are advised to monitor patients closely for any signs of adverse effects or symptoms that may arise from excessive dosing.

In the event of suspected overdosage, it is recommended that healthcare providers initiate supportive care and symptomatic treatment as necessary. Patients should be evaluated for potential complications, and appropriate interventions should be implemented based on the clinical presentation.

For further guidance, healthcare professionals may refer to established protocols for managing drug overdosage or consult a poison control center.

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

Patients should be advised not to wear contact lenses if they exhibit any signs or symptoms of a bacterial ocular infection. Healthcare providers should emphasize the importance of maintaining proper hygiene when using the medication, specifically instructing patients not to touch the dropper tip to any surface, as this may lead to contamination of the solution.

In the event that a patient experiences a sensitivity reaction to tobramycin ophthalmic solution 0.3%, they should be instructed to discontinue use immediately and consult their healthcare provider.

For nursing mothers, it is crucial to discuss the potential risks associated with tobramycin ophthalmic solution, as adverse reactions may occur in nursing infants. A careful decision should be made regarding whether to discontinue nursing or the medication, weighing the importance of the drug to the mother against the potential risks to the infant.

Additionally, healthcare providers should inform patients that the safety and effectiveness of this medication in pediatric patients below the age of 2 months have not been established, and caution should be exercised when considering its use in this population.

Storage and Handling

Tobramycin Ophthalmic Solution, USP 0.3% is supplied in a suitable container that ensures the integrity of the product. It should be stored at a temperature range of 2°C to 25°C (36°F to 77°F) to maintain its efficacy.

Once opened, the solution can be used until the expiration date indicated on the bottle, provided that it has been stored under the recommended conditions. Proper handling and storage are essential to ensure the product remains safe and effective for use.

Additional Clinical Information

No additional information is available regarding laboratory tests, abuse information, or postmarketing experience.

Clinicians should counsel patients on the proper use of the medication, emphasizing that the dropper tip should not come into contact with any surface to prevent contamination of the solution. Additionally, patients exhibiting signs and symptoms of bacterial ocular infection are advised against wearing contact lenses.

FDA Insert (PDF)

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

View full prescribing information (PDF)