Tobramycin

Description

Tobramycin Ophthalmic Solution USP, 0.3% is a sterile topical ophthalmic antibiotic formulation designed for the treatment of external ophthalmic infections. The active ingredient, tobramycin, is a water-soluble aminoglycoside antibiotic effective against a broad spectrum of gram-negative and gram-positive ophthalmic pathogens. The chemical name of tobramycin is O-{3-amino-3-deoxy-α-D-gluco-pyranosyl-(1→4)}-O-{2,6-diamino-2,3,6-trideoxy-α-D-ribohexo-pyranosyl-(1→6)}-2-deoxystreptamine, with a molecular formula of C18H37N5O9 and a molecular weight of 467.52.

Each milliliter of the solution contains 3 mg of tobramycin (0.3%). Inactive ingredients include boric acid, sodium chloride, sodium sulfate, tyloxapol, sodium hydroxide and/or sulfuric acid for pH adjustment (7.0 to 8.0), and water for injection. The formulation also contains benzalkonium chloride as a preservative at a concentration of 0.1 mg (0.01%).

Uses and Indications

Tobramycin Ophthalmic Solution USP, 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 patients.

Appropriate monitoring of bacterial response to topical antibiotic therapy should accompany the use of Tobramycin Ophthalmic Solution USP, 0.3% to ensure optimal therapeutic outcomes.

There are no teratogenic or nonteratogenic effects associated with the use of this medication.

Dosage and Administration

In cases of mild to moderate disease, the recommended dosage is to instill one or two drops into the affected eye(s) every four hours. For severe infections, the dosage is increased to instilling two drops 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 USP, 0.3% is contraindicated in patients with known hypersensitivity to any of its components.

Additionally, to prevent contamination of the solution, patients should avoid touching the dropper tip to any surface.

Warnings and Precautions

Topical ophthalmic use is the sole indication for Tobramycin Ophthalmic Solution USP, 0.3%. It is imperative to note that this solution is not intended for injection into the eye. Patients may experience sensitivity to topically applied aminoglycosides; should a sensitivity reaction occur, the use of this product must be discontinued immediately.

Prolonged use of this antibiotic preparation may lead to the overgrowth of nonsusceptible organisms, including fungi. In the event of a superinfection, it is essential to initiate appropriate therapy. Additionally, cross-sensitivity to other aminoglycoside antibiotics may occur. If a hypersensitivity reaction develops, the product should be discontinued, and suitable therapeutic measures should be implemented.

Patients should be counseled against wearing contact lenses if they exhibit signs and symptoms of bacterial conjunctivitis to prevent exacerbation of their condition.

No specific laboratory tests are recommended for monitoring during the use of Tobramycin Ophthalmic Solution USP, 0.3%. However, healthcare professionals should remain vigilant for any adverse reactions and manage them accordingly.

Side Effects

Adverse reactions associated with Tobramycin Ophthalmic Solution USP, 0.3% include both common and serious events. The most frequently reported adverse reactions are hypersensitivity and localized ocular toxicity, which encompasses lid itching, lid swelling, and conjunctival erythema. These reactions have been observed in less than three out of 100 patients treated with the solution.

Patients may experience sensitivity to topically applied aminoglycosides, including Tobramycin. In the event of a sensitivity reaction, it is advised to discontinue use of the product. Additionally, prolonged use of Tobramycin Ophthalmic Solution may lead to the overgrowth of nonsusceptible organisms, such as fungi. Should a superinfection occur, appropriate therapeutic measures should be initiated.

Cross-sensitivity to other aminoglycoside antibiotics is a potential concern; therefore, if hypersensitivity develops while using this product, it is recommended to discontinue use and provide suitable therapy.

In cases of overdosage, patients may exhibit clinically apparent signs and symptoms that resemble adverse reactions, including punctate keratitis, erythema, increased lacrimation, edema, and lid itching.

Tobramycin Ophthalmic Solution USP, 0.3% is contraindicated in patients with a known hypersensitivity to any of its components.

Drug Interactions

Concomitant use of tobramycin ophthalmic solution with systemic aminoglycoside antibiotics requires caution. It is essential to monitor the total serum concentration of aminoglycosides to avoid potential toxicity.

Additionally, there is a risk of cross-sensitivity to other aminoglycoside antibiotics. In the event that hypersensitivity reactions occur following the use of tobramycin ophthalmic solution, it is advised to discontinue the product immediately and initiate appropriate therapeutic measures.

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 two 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 clinical differences in safety or effectiveness when compared to younger adult 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 treatment to elderly patients.

Pregnancy

Reproduction studies in three types of animals at doses up to thirty-three times the normal human systemic dose have revealed no evidence of impaired fertility or harm to the fetus due to tobramycin, which is classified as Pregnancy Category B. However, there are no adequate and well-controlled studies in pregnant women. Due to the limitations of animal studies in predicting 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 medication in pregnant patients.

Lactation

Because of the potential for adverse reactions in nursing infants from tobramycin, 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

Clinically apparent signs and symptoms of an overdose of tobramycin ophthalmic solution may include punctate keratitis, erythema, increased lacrimation, edema, and lid itching. These manifestations can resemble adverse reaction effects observed in some patients, making it essential for healthcare professionals to differentiate between overdose symptoms and typical side effects.

In the event of an overdose, it is recommended that healthcare providers assess the patient for the aforementioned symptoms. Management should focus on symptomatic relief and supportive care. If necessary, discontinuation of the medication may be warranted to prevent further complications. Monitoring the patient closely for any progression of symptoms is advised, and appropriate interventions should be initiated based on the severity of the clinical presentation.

Nonclinical Toxicology

Reproduction studies conducted in three animal species at doses up to thirty-three 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

Adverse reactions reported in postmarketing experience with tobramycin ophthalmic solution include hypersensitivity and localized ocular toxicity, such as lid itching, swelling, and conjunctival erythema. These reactions have been observed in less than three out of 100 patients treated with tobramycin. Similar reactions may also occur with the topical use of other aminoglycoside antibiotics.

While no additional adverse reactions have been reported specifically from tobramycin therapy, it is advised that when topical ocular tobramycin is administered concomitantly with systemic aminoglycoside antibiotics, careful monitoring of the total serum concentration is warranted.

Patient Counseling

Patients should be advised not to wear contact lenses if they exhibit signs and symptoms of bacterial conjunctivitis. Healthcare providers should emphasize the importance of maintaining proper hygiene when using Tobramycin Ophthalmic Solution USP, 0.3%. Specifically, patients should be instructed not to touch the dropper tip to any surface, as this may lead to contamination of the solution.

For nursing mothers, it is crucial to discuss the potential for adverse reactions in nursing infants due to tobramycin. A careful decision should be made regarding whether to discontinue nursing or the medication, considering the importance of the drug to the mother’s health.

Providers should inform patients that the safety and effectiveness of this medication in pediatric patients under the age of two months have not been established. In the event of a sensitivity reaction to Tobramycin Ophthalmic Solution, patients should be advised to discontinue use immediately.

Additionally, prolonged use of the solution may lead to the overgrowth of nonsusceptible organisms, including fungi. If a superinfection occurs, appropriate therapy should be initiated. Healthcare providers should also be aware of the potential for cross-sensitivity to other aminoglycoside antibiotics; if hypersensitivity develops with this product, it is important to discontinue use and implement suitable therapy.

Storage and Handling

The product is supplied as a sterile solution in a 5 mL plastic dropper bottle. It is essential to store the product at a temperature range of 20° to 25°C (68° to 77°F), in accordance with USP Controlled Room Temperature guidelines. The container must be kept tightly closed to maintain sterility and integrity. Additionally, it is important to protect the product from excessive heat to ensure its efficacy and safety.

Additional Clinical Information

Patients should be counseled on the importance of not touching the dropper tip to any surface to avoid contamination of the solution. Additionally, it is advised that patients refrain from wearing contact lenses if they exhibit signs and symptoms of bacterial conjunctivitis.

FDA Insert (PDF)

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

View full prescribing information (PDF)