Corticosteroids and Ototoxicity: Evidence and Clinical Implications
Corticosteroids are generally not ototoxic when used appropriately, and in some cases may actually be protective against hearing damage. The evidence does not support classifying corticosteroids as ototoxic agents in standard clinical practice.
Evidence on Corticosteroid Safety in the Ear
- Intratympanic (IT) corticosteroids are widely used for treating sudden sensorineural hearing loss, with no evidence of ototoxicity when properly administered 1
- A clinical study of 272 tympanoplasties using polymyxin B, neomycin, and hydrocortisone suspension showed no ototoxic effects, with slight improvements in hearing at most frequencies tested 2
- Corticosteroids are actually used therapeutically to protect against other forms of ototoxicity, particularly cisplatin-induced hearing damage in cancer patients 1
Mechanism of Action in the Inner Ear
- Corticosteroids reduce inflammation, swelling, and edema in the ear canal by suppressing the inflammatory cascade and reducing the release of inflammatory mediators 3
- When administered intratympanically, corticosteroids achieve higher perilymph concentrations than systemic administration, potentially offering greater therapeutic benefit 4
- Dexamethasone and methylprednisolone are the most commonly used corticosteroids for intratympanic administration, with concentrations ranging from 4-24 mg/mL for dexamethasone and 30 mg/mL for methylprednisolone 1
Potential Adverse Effects
- Intratympanic corticosteroids can cause infrequent adverse effects including pain, transient dizziness, infection, persistent tympanic membrane perforation, and possible vasovagal episodes during injection 1
- These side effects are generally mild and transient compared to the potential benefits in appropriate clinical scenarios 1
- While one older animal study questioned potential ototoxicity of hydrocortisone when applied to the round window niche 5, subsequent clinical evidence has not supported this concern 4, 2
Clinical Applications and Safety Considerations
- Corticosteroids are the mainstay of treatment for autoimmune and inflammatory inner ear diseases 6, 4
- In otitis media with effusion (OME), intranasal corticosteroids have not shown significant benefit and are not recommended as routine treatment 1
- For acute otitis externa, topical antibiotic-steroid combinations are highly effective with minimal risk of ototoxicity when the tympanic membrane is intact 3
Important Distinctions and Precautions
- Unlike aminoglycosides, diuretics, certain anti-inflammatory agents, and antineoplastic agents which have established ototoxic potential, corticosteroids are not classified as primary ototoxic agents 7, 6
- Systemic corticosteroids carry significant risks including sleep disturbances, lipodystrophy, adrenal suppression, metabolic syndrome, weight gain, hypertension, and vertebral fractures, but these are not related to ototoxicity 1
- Treatment duration should typically be limited to a single course of no more than 10 days to minimize the risk of adverse systemic effects 3
In conclusion, while corticosteroids should be used judiciously due to potential systemic side effects, the evidence does not support classifying them as ototoxic agents. In fact, they are often used therapeutically to protect against or treat hearing loss from various causes.