Usage
Loteprednol etabonate + Tobramycin is prescribed for steroid-responsive ocular inflammations with a risk of superficial bacterial ocular infection. This includes conditions like allergic conjunctivitis, acne rosacea of the eyelids, superficial punctate keratitis, herpes zoster keratitis (in conjunction with antiviral therapy), iritis, cyclitis, and selected cases of uveitis. Post-operative inflammation following ocular surgery may also be treated with this medication.
It is a combination drug belonging to the following pharmacological classifications:
- Corticosteroid: Loteprednol etabonate is a corticosteroid that reduces inflammation.
- Aminoglycoside Antibiotic: Tobramycin is an antibiotic that kills bacteria or prevents their growth.
The mechanism of action involves the combined effects of loteprednol etabonate and tobramycin. Loteprednol etabonate works by inhibiting the inflammatory response, while tobramycin inhibits bacterial protein synthesis, leading to bacterial cell death.
Alternate Names
The generic name is Loteprednol etabonate + Tobramycin. A common brand name is Zylet.
How It Works
Pharmacodynamics:
Loteprednol etabonate exerts its anti-inflammatory action by suppressing the migration of polymorphonuclear leukocytes and reversing increased capillary permeability. Tobramycin acts on the bacterial ribosome, inhibiting protein synthesis and leading to bacterial cell death.
Pharmacokinetics:
Following topical ophthalmic administration, systemic absorption of both drugs is minimal. Loteprednol etabonate is minimally absorbed, metabolized in the liver, and mostly eliminated as inactive metabolites.
Mode of Action:
Loteprednol etabonate binds to glucocorticoid receptors, modulating inflammatory gene expression. Tobramycin interferes with the 30S ribosomal subunit in susceptible bacteria, preventing protein synthesis.
Elimination:
Minimally absorbed loteprednol etabonate is eliminated in the bile. Any systemically absorbed tobramycin is primarily excreted unchanged in the urine.
Dosage
Standard Dosage
Adults:
Instill one to two drops into the affected eye(s) every four to six hours. During the initial 24 to 48 hours, the dosage may be increased to one to two drops every one to two hours. The dosing frequency should be gradually tapered as the condition improves. The maximum dose is 24 drops/day.
Children:
Safety and efficacy in children have not been established.
Special Cases:
- Elderly Patients: Dosage adjustments are not typically required.
- Patients with Renal Impairment: Dosage adjustments are not typically required.
- Patients with Hepatic Dysfunction: Dosage adjustments are not typically required.
- Patients with Comorbid Conditions: Exercise caution in patients with a history of herpes simplex keratitis.
Clinical Use Cases
The dosage is generally the same for the indications listed in the usage section. This medication is not typically used in clinical settings like intubation, surgical procedures, or the ICU.
Dosage Adjustments
Dosage adjustments are usually based on the patient’s clinical response. If there’s no improvement in signs and symptoms after two weeks, the treatment duration may be extended to four weeks, especially in patients with moderate to severe disease.
Side Effects
Common Side Effects:
Blurred vision, eye irritation, burning or stinging, foreign body sensation, ocular discharge, increased intraocular pressure, photophobia.
Rare but Serious Side Effects:
Allergic reactions (e.g., hives, difficulty breathing, swelling of face), glaucoma, cataracts, secondary ocular infections.
Long-Term Effects:
Glaucoma, cataracts, thinning of the cornea.
Adverse Drug Reactions (ADR):
Severe allergic reactions, significant worsening of the ocular condition, development of fungal keratitis.
Contraindications
Most viral diseases of the cornea and conjunctiva (including epithelial herpes simplex keratitis, vaccinia, and varicella), mycobacterial ocular infections, and fungal diseases of the eye. Hypersensitivity to any component of the medication.
Drug Interactions
No clinically significant drug interactions have been specifically identified.
Pregnancy and Breastfeeding
Loteprednol etabonate + Tobramycin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. There is no information on the presence of the drugs in human milk. Caution should be exercised when administering to nursing mothers.
Drug Profile Summary
- Mechanism of Action: Loteprednol etabonate: Inhibits inflammation. Tobramycin: Inhibits bacterial protein synthesis.
- Side Effects: Blurred vision, eye irritation, burning/stinging, increased IOP, allergic reactions, glaucoma, cataracts, secondary infections.
- Contraindications: Viral or fungal keratitis, hypersensitivity.
- Drug Interactions: No significant interactions reported.
- Pregnancy & Breastfeeding: Use with caution if benefits outweigh risks.
- Dosage: 1-2 drops in affected eye(s) every 4-6 hours, initially. May increase frequency up to every 1-2 hours during the first 24-48 hours.
- Monitoring Parameters: Intraocular pressure (especially with prolonged use), signs of infection, visual acuity.
Popular Combinations
This medication itself is a popular combination. It is not commonly combined with other ophthalmic medications.
Precautions
- General Precautions: Monitor intraocular pressure with prolonged use (greater than 10 days). Do not use with contact lenses.
- Pregnant Women: Use only if potential benefit outweighs risk.
- Breastfeeding Mothers: Use with caution.
- Children & Elderly: Safety and efficacy not established in children. Elderly patients generally do not require dosage adjustments.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Loteprednol etabonate + Tobramycin?
A: The recommended dosage is 1-2 drops in the affected eye(s) every 4-6 hours. During the initial 24-48 hours, more frequent application (every 1-2 hours) may be necessary.
Q2: What are the common side effects?
A: Common side effects include blurred vision, eye irritation, burning or stinging, foreign body sensation, and ocular discharge.
Q3: What are the contraindications for this medication?
A: Contraindications include viral or fungal infections of the cornea or conjunctiva and hypersensitivity to any component of the medication.
Q4: Can this medication be used during pregnancy?
A: It should only be used during pregnancy if the potential benefit outweighs the potential risk to the fetus.
Q5: Is it safe to use this medication while breastfeeding?
A: There is limited information regarding the use during breastfeeding. Caution should be exercised.
Q6: How long can I use Loteprednol etabonate + Tobramycin?
A: Treatment should be limited to the shortest duration possible. Prolonged use (especially over 10 days) increases the risk of side effects like glaucoma and cataracts. Intraocular pressure should be monitored during prolonged use.
A: Contact lenses should not be worn during treatment with this medication.
Q8: What should I do if my symptoms don’t improve?
A: If symptoms do not improve or worsen after a few days, consult an ophthalmologist.
Q9: What should I do if I experience any serious side effects?
A: Immediately discontinue use and consult an ophthalmologist if serious side effects occur, such as severe eye pain, sudden vision changes, or signs of an allergic reaction.
