HIS 125 Ototoxic Medications Overview


Published on

  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

HIS 125 Ototoxic Medications Overview

  1. 1. Various drugs used for therapeutictreatment have the potential side effectsof causing damage to the inner earstructures.
  2. 2.  If the damage progresses, functional hearing impairment and/or balance, with tinnitus is a common complaint. The revealed impairment can be either permanent or temporary and either unilateral of bilateral in nature.
  3. 3. The severity of a patient’s healthcondition may override the concern forototoxic side effects in medicalmanagement. However, one shouldalways be aware of the “quality of life”,and the importance of maintainingfunctional hearing cannot beoveremphasized.
  4. 4.  Almost every major category of medications contains drugs that can be ototoxic. Substances of abuse/excess such as alcohol, marijuana, and tobacco can be toxic to the auditory system. Heavy metals and chemical solvents can also be ototoxic.
  5. 5.  Aminoglycoside AntibioticsAll aminoglycosides are ototoxic to somedegree. Streptomycin, first used in thesuccessful treatment of tuberculosis, wasalso found to be quite ototoxic.
  6. 6.  Aminoglycoside AntibioticsOthers found to be ototoxic include:1. Gentamicin2. Tobramycin3. Amikacin4. Netilmicin5. Kanamycin6. Neomycin
  7. 7.  Aminoglycoside AntibioticsStreptomycin and Gentamicin are oftenused to ablate inner ear structures forthe relief of Menieres syndromesymptoms.
  8. 8.  Aminoglycoside AntibioticsNetilmicin and neomycin may be theleast ototoxic.
  9. 9.  Aminoglycoside Antibiotics Damage caused by them begins at the basal end of the cochlea and progresses toward the apex. The concentration of them will remain high within the perilymph fluid, long after the concentration within the blood has diminished.
  10. 10.  Cancer ChemotherapeuticsThere are significant potentials for ototoxicityamong these drugs. They include:1. Cisplatin2. Carboplatin3. Nitrogen mustard4. Alpha-Difluoromethylornithine (DFMO)
  11. 11.  Cancer ChemotherapeuticsCisplatin may be the most ototoxic of all.Its effects also reveal cochlear damagebeginning at the basal end (high frequency).Carboplatin is a second generation ofCisplatin and was designed to create lessside-effects however, ototoxicity has beenreported with its use.
  12. 12.  Cancer ChemotherapeuticsChemoprotective agents have been designedto reduce the side-effects of anti-tumor drugs.Research into these medications involvesaudiologists who use standardized measuresto monitor success or failure.
  13. 13.  Loop DiureticsThe most common ones of concernare: furosemide and ethacrynicacid.
  14. 14.  Loop DiureticsBy themselves, they usually only create atemporary threshold shift; however,when used with aminoglycosidespermanent cochlear damage may result.
  15. 15. Other commonly used medicationswhich generally result in temporaryhearing loss are: Salicylates (aspirin is most common) Propionic acid (ibuprofen is most common) Quinine (irreversible HL may result when high dosages are used)
  16. 16. There are several factors whichexacerbate or increase the hearing losseffects of ototoxic drugs. Such as: Excessive noise exposure Drug interactions Opportunistic /physiologic susceptibility Pre-existing hearing loss or vestibular disorder.
  17. 17. Audiometry & Ototoxicity monitoring Most ototoxic drugs compromise the basal end (high frequency) area of the cochlea. A high frequency baseline audiogram is recommended before beginning the use of these ototoxic drugs.
  18. 18. Audiometry & Ototoxic monitoringThis monitoring generally involvesfrequencies above 4K, using highfrequency audiometers.
  19. 19. Audiometry & Ototoxic monitoringIdeally, the highest five frequencieswhich the patient responds, are used asthe baseline for future hearing levelmeasurements.For example: 6K, 8K, 12K, 14K, 16K.
  20. 20. Audiometry & Ototoxic monitoring When the threshold at any frequency shifts by more than ten decibels, ototoxic effects may be present. When adjacent frequencies are involved, most certainly effects have occurred. When a twenty decibel shift occurs at any single frequency, ototoxicity effects are present.
  21. 21. Audiometry & Ototoxic monitoring For Aminoglycoside treated patients, audiometric testing should be done every two to four days during treatment. For Cisplatin patients, audiometric testing should be done within twenty-four hours of each treatment.
  22. 22. Audiometry & Ototoxic monitoring Follow-up audiometric testing should be scheduled up to thirty days after Ototoxic treatments have been discontinued. Audiometric monitoring can be very useful in the successful treatment and best practices outcomes for patient healthcare.