Ototoxicity, Presbycusis and Noise Induced Hearing Loss Flashcards
Ototoxicity HL induced by
medications (& others)
Presbycusis HL associated with
aging
Noise-induced hearing loss (NIHL) HL induced by
noise exposure
Who is affected by ototoxicity, presbycusis, and NIHL?
Ototoxicity
Adults and children (high-risk register)
Presbycusis
Adults
Noise-induced hearing loss (NIHL)
Adults and children
How can ototoxicity affect cochleovestibular function?
Partial or total reduction of cochleovestibular function from exposure to toxic chemical substance
What are teratogens?
substances that cause birth defects
What is latrogenic?
complications caused by medical or surgical intervention (caused by HCP)
Ototoxicity =
Ototoxicity = iatrogenic
Do all patients who take ototoxic medications usually get HL?
Not all patients who take ototoxic medications will get hearing loss
Degree of ototoxicity varies
What are the susceptibility risk factors of ototoxicity HL?
Pre-existing hearing loss
Age
Renal function
Drug dosage
Method of administration
Susceptibility risk factors related to:
Mitochondrial gene mutation (12S ribosomal RNA gene in Chinese)
Ototoxic HL presents with: (5)
SNHL
Tinnitus
Dizziness/imbalance
Nausea
Reduced speech discrimination
Give 5 medications that cause ototoxic HL:
Aminoglycosides (antibiotics)
Diuretics
Salicylates
Antimalarial agents
Chemotherapeutic agents
When do we use aminoglycosides?
Commonly used to treat gram-negative bacteria associated sepsis
- UTI or pneumonia
Aminoglycosides are usually given:
IV lines
Poorly absorbed through GI tract
Rarely given as ototopical drops
How do Aminoglycosides affect IE structures?
Directly damage inner ear structures
- Cochlea
Basal turn > apical turn
Outer hair cells > inner hair cells > stria vascularis - Vestibular organ
Utricle and saccule
Vertigo/dizziness may be present
How does ototoxic HL due to aminoglycosides appear on the audiogram?
High frequency affected first (> 8 KHz)
May not initially be detected by audiogram
Bilateral SNHL
Irreversible
Acute or chronic loss
Aminoglycosides: Neomycin and Kanamycin
are more likely to cause________________
cochlear toxicity first
Aminoglycosides: Gentamycin and Streptomycin are more likely to cause________________
to cause vestibular toxicity first
Intratympanic therapy used in severe Meniere’s disease (close monitoring required)
When used in early pregnancy, some aminoglycosides may cause ______________________________________________________
When used in early pregnancy, some aminoglycosides may cause ototoxicity and other congenital anomalies in the newborn
How do diuretics affect your system and hearing?
Affects the fluid flow in your body
Damages the stria vascularis
Tinnitus and vertigo
May be temporary/reversible SNHL
High doses can cause permanent SNHL
Salicylates are commonly found in ________________________ and ____________________________
Salicylates are commonly found in antipyretics and analgesics
Antipyretics are:
Antipyretics-fever relieving drugs
Analgesics are:
Analgesics-pain relieving drugs
How do salicylate drugs affect hearing?
Mechanism of HL
Reduced blood flow to cochlea
(No hair cell loss)
What are features of salicylates hearing loss?
Common cause of high frequency tinnitus
Reversible, mild to moderate SNHL (rarely permanent)
What are antimalarial agents? (3)
Not commonly used in North America
Originally thought malaria caused hearing loss but it was the drug to treat malaria
Hearing loss depends on the dose
How do Quinine drugs affect hearing?
A similar mechanism as aspirin
Reduced blood flow to the cochlea
Reversible, bilateral SNHL
Rarely dizziness
High-pitched tinnitus
What are Chemotherapeutic Agents?
Systemic cancer treatment drugs
Most agents kill cells that divide rapidly (main properties of cancer cells)
Other normal cells that divide rapidly include bone marrow, digestive tract and hair follicles
They are also targeted
Chemotherapeutic Agents affect
Bone marrow causing:
Digestive tract:
Hair follicles:
Bone marrow causing: immunosuppression
Digestive tract: mucositis (inflammation of lining of GI tract)
Hair follicles: hair loss