What is the recommended dosing of ofloxacin (a fluoroquinolone antibiotic) for adult patients with otitis externa?

From the Guidelines

For adult otitis externa, ofloxacin otic solution 0.3% is typically dosed as 5-10 drops into the affected ear(s) twice daily for 7 days. This dosing regimen is based on the most recent and highest quality study available, which emphasizes the importance of topical antimicrobials in treating acute otitis externa 1. Before application, the ear canal should be gently cleaned and dried to ensure effective treatment. The patient should lie with the affected ear upward for 5 minutes after instillation to ensure the medication reaches the entire ear canal.

• Ofloxacin is effective against most common pathogens causing otitis externa, including Pseudomonas aeruginosa and Staphylococcus aureus, which are responsible for nearly all cases of acute otitis externa in North America 1.
• This fluoroquinolone antibiotic works by inhibiting bacterial DNA gyrase, preventing DNA replication and ultimately killing the bacteria.
• Patients should complete the full course of treatment even if symptoms improve before completion to prevent recurrence or antibiotic resistance.
• If symptoms worsen or do not improve after 7 days, patients should seek further medical evaluation as they may need alternative treatment or further assessment for complications.

From the FDA Drug Label

For patients 13 years and older: Ten drops (0.5 mL, 1. 5 mg ofloxacin) instilled into the affected ear once daily for seven days. The recommended ofloxacin dosing for adult otitis externa is ten drops (0.5 mL, 1.5 mg ofloxacin) instilled into the affected ear once daily for seven days 2.

• The solution should be warmed by holding the bottle in the hand for one or two minutes to avoid dizziness which may result from the instillation of a cold solution.
• The patient should lie with the affected ear upward, and then the drops should be instilled.
• This position should be maintained for five minutes to facilitate penetration of the drops into the ear canal.

From the Research

Ofloxacin Dosing for Adult Otitis Externa

• The recommended dosing for ofloxacin in the treatment of adult otitis externa is 0.3% otic solution, with various studies indicating different administration frequencies and durations 3, 4, 5.
• A study published in 1999 found that ofloxacin otic solution 0.3% was as effective as topical neomycin/polymixin B/hydrocortisone preparations in the treatment of otitis externa, with a clinical cure rate of over 80% in adults 3.
• Another study published in 2004 evaluated the efficacy and safety of ofloxacin otic 0.3% solution administered once daily for 7 days in the treatment of otitis externa, and found a cure rate of 91% among clinically evaluable patients, with 68% of patients cured within 7 days 4.
• A study published in 1997 compared the safety and efficacy of ofloxacin otic solution with Cortisporin otic solutions in otitis externa in adults and children, and found that ofloxacin given twice daily was as safe and effective as Cortisporin given 4 times daily 5.
• The dosage of ofloxacin for adult otitis externa can be summarized as follows:
  • 0.3% otic solution, 10 drops, twice daily for 10 days 3, 5
  • 0.3% otic solution, 10 drops, once daily for 7 days 4

Safety and Efficacy

• Ofloxacin otic solution 0.3% is well tolerated, with adverse events usually classed as mild to moderate, and the most frequent adverse events being bitter taste and pruritus 3.
• The incidence of adverse events with ofloxacin otic solution 0.3% is similar to that with other ototopical preparations and significantly less than that with oral amoxicillin/clavulanic acid 3.
• Ofloxacin otic solution 0.3% is not associated with ototoxicity, and is effective in achieving clinical and microbiologic cure of otitis externa 3, 4.