OTOTOXIC DRUGS
Rx
SIGN ed Prescription
Catherine H. Tuazon, M.D.
There are many causes of deafness and this includes exposure to loud noise, heredity, trauma, disease, age related deafness and drugs. For this issue, I will touch more on the most common drugs that cause damage to the ears.
- Antibiotics- Drugs used to treat infections caused by bacteria and other microorganisms
Aminoglycoside group of antibiotics include Streptomycin, Kanamycin, Amikacin and Gentamycin Streptomycin is an injectable antibacterial that is used in the treatment of tuberculosis. About 4 to 15% of patients who receive 1 g/day for > 1 wk develop measurable hearing loss, which usually occurs after a short latent period (7 to 10 days) and slowly worsens if treatment is continued. Complete, permanent deafness may follow. Macrolide group of antibiotics include erythromycin, azithromycin The ototoxicity due to erythromycin is related to dosage. The hearing losses due to erythromycin appear to occur in speech frequencies at the same time the deficit occurs at higher frequencies. For this reason, the patient can easily recognize a change in hearing. Azithromycin can be quite toxic to the inner ear in patients who are undergoing treatment for human immunodeficiency virus (HIV) infection.
Neomycin has the greatest cochleotoxic effect of all antibiotics
The most commonly used chemotherapeutic agent and a major ototoxic agent among these compounds is cisplatin. It contains platinum and can cause tinnitus and hearing loss. The tinnitus may be transient or permanent Hearing loss can be profound occurring immediately after the first dose, or can be delayed until several months after completion of treatment. Sensorineural hearing loss strikes bilaterally, progresses decrementally, and is permanent.
Nitrogen mustard, the first clinically useful chemotherapeutic agent causes severe damage to the ear. The toxicity has been characterized by irreversible sensorineural hearing loss and tinnitus.
- Diuretics - A substance or drug that tends to increase the discharge of urine.
- Ethacrynic acid and furosemide given intravenously have caused profound, permanent hearing loss in patients with renal failure who were receiving aminoglycoside antibiotics.
- Antiinflammatory Drugs
Salicylates (aspirin ) in high doses (> 12 325-mg tablets of aspirin per day) cause temporary hearing loss and tinnitus. Manifestations of salicylate ototoxicity are quite well-known: nausea, vomiting, tinnitus, hearing loss, headache, mental changes, and increased respiration. The hearing loss is typically mild to moderate and bilaterally symmetric. It may be flat or just in the high-frequencies. Recovery usually occurs twenty-four to seventy-two hours after cessation of the drug
Quinine and its synthetic substitutes used for the treatment of malaria can also cause temporary hearing loss. Transient hearing loss, usually a first side effect, occurs a few hours after initiating high-dose therapy. With prolonged treatment, patients can be expected to suffer hearing loss. The sensorineural hearing loss is usually reversible bilaterally and symmetric, particularly affecting the high-frequencies first.
Providone iodine preparations and chlorhexidine have both been proven to be toxic to the cochlea and vestibular sensory neuroepithelium in the inner ear after reaching the middle ear space.
Prevention
To avoid damage to the organs of hearing , one should not self-medicate. It is better to consult a medical practitioner before taking any drug. Read also the package insert before taking any over the counter preparations.
*ototoxic- having a deleterious effect upon the eighth nerve or on the organs of hearing and balance.
*tinnitus- a noise in the ears, such as ringing, buzzing, roaring, or clicking.