About Ototoxic Medications
Ototoxicity is the property of being toxic to the ear, specifically the cochlea or auditory nerve and sometimes the vestibular system, for example, as a side effect of a drug. Some medications can have ototoxic side effects, such as causing ringing in the ears, loss of balance, internal noises in the auditory system, dizziness, etc.
Ototoxic medications cause damage to the sensory cells used in hearing and balance. These sensory cells are located in the inner ear. Certain medications can damage the ear, resulting in hearing loss, ringing in the ear, or balance disorders. Such drugs are considered ototoxic.
Try to avoid the use of ALL medications that may adversely affect the results of Auditory Integration Training.
This is a partial listing of those medications about which we have information. There are undoubtedly others which we are not yet aware of, and new drugs become available constantly, so this is NOT A COMPLETE LISTING.
It is recommended that you check with your physician and pharmacist, or use the Physician’s Desk Reference to check on medications.
There are more than 200 known ototoxic medications (prescription and over-the-counter) on the market today. It is important to discuss with your doctor the potential for hearing or balance damage of any drug you are taking. Sometimes there is little choice. Treatment with a particular medication may provide the best hope for curing a life-threatening disease or stopping a life-threatening infection. These include medicines used to treat serious infections, cancer and heart disease. Hearing and balance problems caused by these drugs can sometimes be reversed when the drug therapy is discontinued. However, sometimes the damage is permanent. When a decision is made to treat a serious illness or medical condition with an ototoxic drug, your health care team should consider the effects of the medications on your hearing and balance systems. The team should discuss with you how these side effects will affect your quality of life.
List 1. Most Dangerous Ototoxic (Toxic to the Ear) Medications
Aminoglycoside antibiotics - Amikacin, Gentamicin, Kanamycin, Neomycin (Neosporin)
List 2: Controversial - Potentially Ototoxic Medications
List 3. In Rare Cases Are Ototoxic Medications
Ampicillin - antibiotic
Antimicrobial Phisohex - topical antibacterial cleanser
The following medications also have potential side effects that might affect the auditory system according to the Physician’s Desk Reference:
Beta Blockers (Propranolol, Corgard)
HCI (Norpramin, Gantricin, Garamycin, Naltrexone (Trexan)
Tegretol IV Ceclor reportedly may cause auditory hypersensitivity
Aminoglycosides and Ototoxicity: These include kanamycin, neomycin, amikacin, streptomycin, and gentamicin. They are toxic to the cochlea and also affect the stria vascularis, causing vestibular problems. They produce damage through the ability to generate free radicals in the inner ear. Babies have suffered congenital deafness when their mothers took kanamycin or streptomycin during pregnancy. Neomycin is the worst offender relating to cochlear toxicity. Aminoglycosides are especially toxic when instilled into the ear. Gentamici is both vestibular otoxic and causes vertigo or is cochlear toxic, causing hearing loss.
Antineoplastics: Cisplatin affects the cochlea and stria vascularis through its ability to generate free radicals within the inner ear. Researchers have examined various compounds with possible protective activity that might be administered concomitantly with cisplatin to prevent ototoxicty.However, none of those investigated are clearly effective.
Loop Diuretics: Loop diuretics include furosemide, ethacrynic acid and bumetanide. They affect the potassium gradient of the stria vascularis, as well as the electrical potential of the endocochlear structure. They produce tinnitus and hearing loss. The hearing loss may be perceptible or may be apparent only with audiometric testing. Their toxicity is dose-related. Ototoxicity is more likely when the patient receives a rapid infusion of injectable loop diuretics in renal failure, which allows the medications to accumulate. Ototoxicity from furosemide is usually reversible but may be permanent in rare instances Ethacrynic acid no longer used due to the potential for ototoxicity, especially when given intravenously those whose regimen also included aminoglycosides
Antineoplastics: Cisplatin affects the cochlea and stria vascularis through its ability to generate free radicals within the inner ear. Researchers have examined various compounds with possible protective activity that might be administered along with cisplatin to prevent ototoxicty. However, none of those investigated are clearly effective.
Quinine: Quinine has the potential to cause tinnitus, loss of hearing or vertigo. The hearing loss may be irreversible. It was once widely sold as a non-prescription product. However, the FDA found its traditional use for nocturnal leg cramps was ineffective. They issued an opinion that it is outdated as an anti-malarial as well.The Patients who take 200 to 300 mg of quinine over a sustained period experience a 20% risk of hearing loss.
Salicylates: Salicylates impact the cochlea. In high doses, they cause tinnitus and loss of hearing. Both are usually seen only with higher doses and stop the low on discontinuation in most instances. The relationship between salicylate serum concentrations and the level of hearing loss is linear. Serum concentrations below 20 to 50 mg/dL produce little risk of hearing loss. Concentrations exceeding this level expose the person yo a possible hearing loss of 30 decibels or above. Hearing loss could occur with topical administration of counterirritants containing methyl salicylate. It is preferable to consider the use of therapeutic heat wraps as a safer alternative for knee or back pain or for pains in the shoulder-to-arm area, particularly in patients with risk factors that would predispose them to ototoxicity.
Taking More Than One Ototoxic Medication At A Time: If more than one potentially ototoxic medication is given to the same person, the effect can be increase. If a person is already taking a potentially ototoxic medication, any addition should be examined carefully to detect additional ototoxins.
Tea Tree Oil: Tea tree oil is an alternative medical treatment effective for bacteria and fungi. In one article, researchers discovered that it may be toxic to the cochlea, producing deficiency in the high-frequency region of hearing. Therefore, it must be used with caution and using tea tree oil in the ears for an infection appears unwarranted due to the lack of information on efficacy and should also be avoided to prevent possible cochlear toxicity. Use homeopathy for ear infections instead!
Preparations. Treatment of ear disease can be
accomplished with the use of systemic or topical preparations. Drug
therapy cannot achieve the concentrations allowed with the use of
ototopical drops, so topical drops also have the advantages of rapid
delivery, good compliance and lower cost. Some drops are combinations of
two or more ingredients. If the product is used for otitis externa, the
danger in the application of potentially ototoxic medications is that
the person might have a perforation in the eardrum. This perforation
might have occurred as a result of trauma, otitis media, or following
placement of ventilation tubes. If a perforation is present,
instillation of preparations with ototoxic potential could lead to inner
ear damage. Topical medications, such as those containing
neomycin/polymyxin B, may
produce vestibular and/or cochlear toxicity when the person has a
perforated ear drum.
Note: Otitis externa (inflammation or infection of the external auditory canal) can be treated with quinolones, such as ofloxacin otic drops (Floxin Otic), without fear of ototoxicity.
Importance of Dose and Dosing Interval of Ototoxic Medications
If a medication has ototoxic potential, its blood levels should remain as low as possible. This may require assessing blood levels frequently and adjusting the dosage downward if blood levels exceed those required to gain the desired therapeutic effect.
Tinnitus: Usually the first sign of ototoxicity is ringing in the ears, called tinnitus. A hearing loss may also develop over time. This hearing loss may go unnoticed until your ability to understand speech is affected.
Balance Problems: Balance problems can also occur as a result of ototoxic medications. A loss of balance and and feeling unsteady on your feet may occur. Sometimes these problems are temporary because the human body can learn to adapt to reduced balance control. Hearing and balance problems caused by ototoxic drugs can sometimes be reversed when the drug therapy is discontinued.
Dizziness: The effects of ototoxic medications can affect your quality of life. Not being able to hear conversations or feeling a little dizzy may cause you to stop participating in usual activities.
Hearing: Hearing problems that are caused by ototoxic drugs can sometimes be reversed when the drug therapy is discontinued.
Dizziness:The effects of ototoxic medications can affect your quality of life. Not being able to hear conversations or feeling a little dizzy may cause you to stop participating in usual activities.
Permanent Damage: Ototoxic medications known to cause permanent damage include certain aminoglycoside antibiotics, such as gentamicin (note: a family history may increase susceptibility) and cancer chemotherapy drugs, such as cisplatin and carboplatin.
Temporary Damage: Drugs known to cause temporary damage include salicylate pain relievers, aspirin, used for pain relief and to treat heart conditions), quinine (to treat malaria) and loop diuretics, to treat certain heart and kidney conditions).
Loud Noise Exposure: In some instances, exposure to loud noise while taking certain drugs will increase their damaging effects.
There are three major locations where medications cause ototoxicity.
Cochlea: Some ototoxic medications are "cochleotoxicity". Ototoxicity involving the cochlea produces hearing loss, usually commencing with high frequencies but often eventually progressing to the lower frequencies that encompass speech. The hearing loss may be one-sided or both sides and may fluctuate in severity. Cochlear damage may also manifest as tinnitus. The tinnitus may be constant or fluctuate. Those with preexisting tinnitus may notice the problem worsening or the appearance of a new sound that was not present before the medication was administered.
Vestibulum: Some ototoxic medications are "vestibulotoxic" medications. Vestibulotoxicity shows often as balance-related problems or disequilibrium. The person reports a spinning sensation that is often aggravated by motion and is associated with nausea.
Stria Vascularis: Some ototoxic medications effect the stria vascularis. The stria vascularis is a type of epithelium that is uniquely able to produce endolymph, which is the the fluid in the membranous labyrinth of the ear, in the cochlea. Too much endolymph causes Meniere's syndrome.
You should monitor your hearing and balance systems before and during treatment. Before starting the treatment, a baseline record of your hearing and balance can be recorded by an audiologist. The baseline record should include an audiologic hearing test that uses high-pitched testing, word recognition, and other tests when possible. This information can help you and your doctor make any important decisions to stop or change the drug therapy before your hearing is damaged.
For cases in which the drugs cannot be stopped or changed, the patient and the audiologist can take steps to manage the effects of the hearing loss that results.
During the course of your treatment, you should have periodic hearing tests as part of the monitoring process. This will help enable you to report any hearing changes, ringing in the ears, or balance problems that you may notice.