Ototoxic medication

Ototoxic Medication

Anatomy of the Human Ear

Ototoxic medications are drugs that have the potential to cause damage to the ear, specifically the cochlea or auditory nerve, leading to hearing loss or tinnitus. These medications can affect the inner ear structures responsible for hearing and balance, and their effects can be temporary or permanent.

Mechanism of Ototoxicity

Ototoxicity can occur through various mechanisms depending on the class of medication. Some drugs may directly damage the hair cells in the cochlea, while others may interfere with the blood supply to the inner ear or disrupt the electrolyte balance within the ear's fluid compartments.

Aminoglycosides

Bacterial Protein Synthesis

Aminoglycosides, such as gentamicin and streptomycin, are antibiotics that can cause ototoxicity by binding to the ribosomal RNA of bacteria, inhibiting protein synthesis. This action can also affect the mitochondria of human cells, leading to the production of reactive oxygen species that damage cochlear hair cells.

Chemotherapeutic Agents

Chemical structure of cisplatin and carboplatin

Chemotherapeutic agents like cisplatin and carboplatin are known to cause ototoxicity. These drugs can induce apoptosis in cochlear cells by forming DNA adducts and generating oxidative stress, leading to cell death and hearing loss.

Loop Diuretics

Loop diuretics, such as furosemide, can cause ototoxicity by altering the ionic composition of the endolymph in the cochlea. This disruption can lead to edema and damage to the hair cells, resulting in hearing impairment.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Cyclooxygenase enzyme

NSAIDs, including aspirin and ibuprofen, can cause reversible ototoxicity. They inhibit the cyclooxygenase (COX) enzymes, reducing the production of prostaglandins, which can affect cochlear blood flow and lead to temporary hearing loss.

Symptoms of Ototoxicity

The symptoms of ototoxicity can vary depending on the drug and the individual. Common symptoms include:

• Tinnitus (ringing in the ears)
• Hearing loss, which can be unilateral or bilateral
• Vertigo or balance disturbances
• A feeling of fullness in the ears

Prevention and Management

To prevent ototoxicity, it is important to monitor drug levels and adjust dosages appropriately. Regular audiometric testing can help detect early signs of hearing loss. In some cases, alternative medications with lower ototoxic potential may be used.

Management of ototoxicity involves discontinuing the offending drug if possible and providing supportive care. Hearing aids or cochlear implants may be necessary for those with significant hearing loss.

Related Pages

• Hearing loss
• Tinnitus
• Cochlea
• Antibiotics
• Chemotherapy