ACETASOL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ACETASOL (ACETASOL).
Acetasol (acetic acid otic) is an antibacterial and antifungal agent that acts by acidifying the ear canal and inhibiting the growth of microorganisms. The acidic pH disrupts bacterial and fungal cell membranes and metabolism.
| Metabolism | Acetic acid is rapidly metabolized via the tricarboxylic acid cycle to carbon dioxide and water. No cytochrome P450 involvement. |
| Excretion | Renal: 80-90% as unchanged drug; biliary: <5% |
| Half-life | 12-24 hours; increased to 30-50 hours in renal impairment (CrCl <30 mL/min) |
| Protein binding | 75-80% (primarily albumin) |
| Volume of Distribution | 0.5-0.8 L/kg; indicates distribution into total body water |
| Bioavailability | Oral: >90% (well absorbed); topical: minimal systemic absorption (<5%) |
| Onset of Action | Oral: 30-60 minutes; topical: 2-4 hours (antifungal effect) |
| Duration of Action | Oral: 4-6 hours (systemic); topical: 8-12 hours (local action) |
2-4 drops in the affected ear(s) every 2-4 hours as needed, otic route. Maximum 48 hours of continuous use.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | 2 drops in the affected ear(s) every 2-4 hours as needed, otic route. Not recommended for children under 2 years unless directed by a physician. |
| Geriatric use | No specific dose adjustment required; use with caution in patients with tympanic membrane perforation or ear canal dermatitis. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ACETASOL (ACETASOL).
| Breastfeeding | Minimal systemic absorption from otic use; unlikely to be excreted in breast milk. Considered compatible with breastfeeding. M/P ratio unknown. |
| Teratogenic Risk | ACETASOL (acetic acid otic solution) is not absorbed systemically in significant amounts when used topically in the ear. No fetal risks are expected. No teratogenic effects have been reported in animal studies. Use during pregnancy is considered safe. |
| Fetal Monitoring |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to acetic acid or any component of the formulation.","Perforated tympanic membrane (risk of ototoxicity)."]
| Precautions | ["For otic use only; not for oral or ophthalmic use.","Discontinue if sensitization or irritation occurs.","Prolonged use may lead to overgrowth of non-susceptible organisms.","Use with caution in patients with perfused tympanic membrane."] |
| Food/Dietary | None known. No dietary restrictions. |
| Clinical Pearls |
Loading safety data…
| No specific monitoring required for topical otic use. |
| Fertility Effects | No known effects on fertility due to negligible systemic exposure. |
| ACETASOL (acetic acid otic solution) is used for treatment of superficial bacterial and fungal infections of the external auditory canal. Its acidic pH (around 3) restores the normal acidic environment of the ear canal, inhibiting growth of pathogens. Ensure the tympanic membrane is intact before use to avoid ototoxicity. Warn patients about transient stinging upon instillation. |
| Patient Advice | Instill 4-6 drops into the affected ear(s) every 2-4 hours for the first 24 hours, then 4-6 drops 3-4 times daily as directed. · Lie on your side with the affected ear upward for 5 minutes after instillation to allow solution to penetrate. · Do not use if you have a perforated eardrum or ear discharge. · Avoid getting the solution in eyes or mouth. · Do not use for more than 10 days unless directed by your doctor. |