Final Exam lectures 11, 12 & 13. Flashcards
Damage to the inner ear, targeting cochlear and vestibular structures and sensory function, due to exposure to certain pharmaceuticals, chemicals, and/or ionizing radiation
ototoxicity/vestibulotoxicity
ototoxicity/vestibulotoxicity
Damage to the inner ear, targeting cochlear and vestibular structures and sensory function, due to exposure to certain pharmaceuticals, chemicals, and/or ionizing radiation
It is the alteration of hearing or balance by drugs and chemicals acting at the level of brainstem or central connections of the cochlear and vestibular nuclei
neurotoxicity
Define neurotoxicity
It is the alteration of hearing or balance by drugs and chemicals acting at the level of brainstem or central connections of the cochlear and vestibular nuclei
Define hepatotoxicity
Causes liver damage, will result in metabolism issues and toxicity because the drug will not be able to excrete the body appropriately and will sit in the liver too long
Causes liver damage, will result in metabolism issues and toxicity because the drug will not be able to excrete the body appropriately and will sit in the liver too long
hepatotoxicity
Tubular cell injury because of drug accumulation, which may be reversible
It contributes to ototoxicity because renal toxicity causes the drug to accumulate and stay longer in the body
nephrotoxicity
nephrotoxicity
Tubular cell injury because of drug accumulation, which may be reversible
Kidney
It contributes to ototoxicity because renal toxicity causes the drug to accumulate and stay longer in the body
risk factors for ototoxicity
Dosage
Hepatic function
Renal function
polypharmacology
Age
Pre-existing SNHL
Discuss the rationale for the high frequency sensorineural hearing loss related to ototoxicity
The outer hair cells are the first to be destroyed from the base to the apex resulting in a high frequency SNHL
During Ototoxicity what physiology occurs?
The outer hair cells are the first to be destroyed from the base to the apex resulting in a high frequency SNHL
Discuss ototrauma and its effects
Very loud noise; sudden onset with short duration
Very loud noise; sudden onset with short duration
Ototrauma
List primarily ototoxic drugs
Amikacin and neomycin are more ototoxic
List Primarily vestibulotoxic drugs
Streptomycin and gentamicin are more vestibulotoxic
Amikacin and neomycin are more _____
Ototoxic
Streptomycin and gentamicin are more _______
vestibulotoxic
One antibiotic can cancel out desired effects of the other
Antibiotic antagonism
Antibiotic antagonism
One antibiotic can cancel out desired effects of the other
Antibiotic antagonism example
if tetracycline and penicillin are given together, penicillin will not be effective
Antibiotic synergism
Using more than one antibiotic increases the spectrum of kill and produces a desired effect of greater magnitude
Using more than one antibiotic increases the spectrum of kill and produces a desired effect of greater magnitude
Antibiotic synergism
Antibiotic Synergism examples
streptomycin given with penicillin, will kill the enterococci bacteria completely
Limitation of Antibiotic Synergism
Use of multiple antibiotics raises the risk of polypharmacy and adverse reactions including ototoxicity
The target organism for antibiotic therapy
- The target organism for antibiotics are ** bacteria**
- Antibiotics are
ineffective against virus - Affect both gram-positive and gram-negative bacteria
Bacteria that stain dark blue or violet by Gram staining because of high amounts of peptidoglycan in cell wall
Gram-positive bacteria
(positive, Lilys fav color)
Gram-positive bacteria
Bacteria that stain dark blue or violet by Gram staining because of high amounts of peptidoglycan in cell wall
Bacteria cannot retain the crystal violet stain because they typically lack the outer membrane found in gram-positive bacteria
Instead they take up the counterstain (e.g., safranin or fuchsine) and appear red or pink
Gram-negative bacteria
Red, Negative- Inside out
Gram-negative bacteria
Bacteria cannot retain the crystal violet stain because they typically lack the outer membrane found in gram-positive bacteria
Instead they take up the counterstain (e.g., safranin or fuchsine) and appear red or pink
pathophysiology of ototoxicity
- Loss of hair cells is most severe at the cochlear basal turn moving towards the apex
- structures damaged include; Stria vascularis, spiral ligament, Reissner’s membrane
- Nerve fiber damage is secondary to hair cell loss
- Loss of hair cells is most severe at the cochlear basal turn moving towards the apex
- structures damaged include; Stria vascularis, spiral ligament, Reissner’s membrane
- Nerve fiber damage is secondary to hair cell loss
pathophysiology of ototoxicity
Identify common classes of antibiotics
Aminoglycosides
Penicillin
Macolides
Aminoglycosides indications
Used to treat infections caused by aerobic gram-negative bacteria that can cause serious and life-threatening infections, for e.g.,
- Endocarditis
- Septicemia
- Kidney infections
All the above conditions in turn can increase the risk of ototoxicity
Penicillin Indications
- Amoxicillin is one of the most commonly prescribed drugs in the U.S. for otitis media
- Augmentin is used for otitis media if patients develop resistance or no benefits from amoxicillin
Generally penicillin is not considered to be ototoxic or vestibulotoxic
- Amoxicillin is one of the most commonly prescribed drugs in the U.S. for otitis media
- Augmentin is used for otitis media if patients develop resistance or no benefits from amoxicillin
Penicillin Indications
Second generation Penicillin
Ampicillin, Amoxicillin, Amoxicillin with Clavulanic Acid (Augmentin)
Used to treat infections caused by aerobic gram-negative bacteria that can cause serious and life-threatening infections, for e.g.,
- Endocarditis
- Septicemia
- Kidney infections
All the above conditions in turn can increase the risk of ototoxicity
Aminoglycosides indications
_________ is one of the most commonly prescribed drugs in the U.S. for otitis media
Amoxicillin is one of the most commonly prescribed drugs in the U.S. for otitis media
_______ is used for otitis media if patients develop resistance or no benefits from ________
Augmentin is used for otitis media if patients develop resistance or no benefits from amoxicillin
Amoxicillin is one of the most commonly prescribed drugs in the U.S. for _________
otitis media
Augmentin is used for otitis media if patients ______ ______ or _____ _____ from amoxicillin
Augmentin is used for otitis media if patients develop resistance or **no benefits ** from amoxicillin
True or False
penicillin is ototoxic & vestibulotoxic
FALSE
penicillin is not considered to be ototoxic or vestibulotoxic
Other structures damaged during ototoxicity
Stria vascularis, spiral ligament, Reissner’s membrane
Nerve fiber damage is secondary to hair cell loss
During Ototoxicity
____________ are affected first
___________ and rest of the _________ can be damaged in more severe cases
Outer hair cells are affected first
Inner hair cells and rest of the organ of corti can be damaged in more severe cases
True or False
Aminoglycosides only cause permanent functional effects
FALSE
Aminoglycosides can result in ** both ** acute physiological and permanent functional effects
- Hearing loss can sometimes be reversible following discontinuation of drug
what is the Primary target of aminoglycoside antibiotics
Cochlear hair cells are the primary targets of aminoglycoside antibiotics
During Aminoglycosides in the vestibular system what occurs?
- Type 1 hair cells are lost first
- Primary site of lesion depends on the drug,
- All aminoglycosides can damage one or both end organs
True or False Ototoxicity and vestibulotoxicity with aminoglycosides is always Dose dependent?
FALSE
Ototoxicity and vestibulotoxicity with aminoglycosides is dose-dependent unless it’s genetic ototoxicity
Ototoxic monitoring after drug discontinued
ototoxic hearing loss can be progressive, occurring > 6 to 12 months after drug regimen is discontinued
Ototoxic monitoring is necessary for several weeks and months after the drug is discontinued
** - After discontinuation, 3, 6, 9, 12 months of monitoring *** (3 mos 1st year)
** - Annually for platinum based drugs **
What drug is used to treat
Endocarditis
Septicemia
Kidney infections
Aminoglycosides
What drug primarily used to treat otitis media?
Penicillin
Amoxicillin & Augmentin
What drug is used to treat
Otitis media
Respiratory tract infections including
- Strep throat,
tonsillitis, pharyngitis
Sexually transmitted diseases
Useful when patients are allergic to penicillin
Macrolides Indications
Macrolides Indications
Otitis media
Respiratory tract infections including
- Strep throat,
tonsillitis, pharyngitis
Sexually transmitted diseases
Useful when patients are allergic to penicillin
Which antibiotics are commonly used to treat otitis media?
Penicillin
- Amoxicillin & Augmentin
Macrolides
- Erythromycin, clindamycin, azithromycin
Which antibiotics are MOST often associated with ototoxicity?
Aminoglycosides
Macrolides (generally reversible)
Glycopeptide antibiotics (e.g., vancomycin)
_____ , ______dividing cells respond best to chemotherapy
Small, rapidly dividing cells respond best to chemotherapy
______ _______ do not respond well to chemotherapy
Solid tumors do not respond well to chemotherapy
Why do Solid tumor not respond well to chemo?
Because of the slower growth/division of these cells
These tumors often require radiation and/or surgery as well
Why are normal cells affected by chemotherapy
Normal cells also rapidly divide and are subjected to the effects of chemotherapy
Tumor cells mutate, which allows them to_______
Tumor cells mutate, which allows them to metastasize
What is it when a tumor Metastasize
- Original tumors may respond well to chemotherapy, but metastatic lesions may be less responsive, poor prognosis
- Because as they mutate, their response to chemotherapy may change (e.g., altered cell receptors)
Describe the challenges associated with antineoplastic combination chemotherapy
Antineoplastic = chemotherapeutic medications
- particularly platinum-based drugs
This fact results in dose-limiting toxicities
- The challenge is to give an adequate dose to kill the cancer cells without killing too many healthy cells
Many toxicities
what is Antineoplastic
Antineoplastic = chemotherapeutic medications
List Platinum-derived compound
Cisplatin
Carboplatin
Multifactorial mechanism of Cisplatin Ototoxicity (60%)
Indications for what drug
Germ cell tumors
- Ovarian & testicular tumors (including metastatic lesions)
Bladder cancer
Gynecological
Lung tumors
Tumors of head/neck region and brain tumors
Many childhood tumors including neuroblastoma
Cisplatin
Cisplatin indications
Germ cell tumors
- Ovarian & testicular tumors (including metastatic lesions)
Bladder cancer
Gynecological
Lung tumors
Tumors of head/neck region and brain tumors
Many childhood tumors including neuroblastoma
Indications for what drug
is the same as cisplatin, Less nephrotoxicity, equal ototoxic and more vestibulotoxic
Carboplatin
Carboplatin indications
SAME AS cisplatin
Germ cell tumors
- Ovarian & testicular tumors (including metastatic lesions)
Bladder cancer
Gynecological
Lung tumors
Tumors of head/neck region and brain tumors
Many childhood tumors including neuroblastoma
What drug treats tumors and less Nehrotoxic, Same ototoxic but more vestibulotoxic in comparison to cisplatin
Carboplatin
Carboplatin Limiations
- ototoxic I s equal to cisplatin
- more vestibulotoxic
- Significant bone marrow toxicity, which is dose limiting
- BM Toxicity can be overcome by treatment with stem cell rescue - Mechanism of toxicity is probably reactive oxygen and nitrogen species
Toxicity risk increases with previous cisplatin or aminoglycoside administration
Multifactorial mechanism of Cisplatin-induced ototoxicity
Damage caused by free radical generation and inhibition of anti-oxidation processes
Cisplatin-induced Permanent hearing loss is probably caused by
Loss of OHCs in the basal turn initially resulting in earlier high frequency SNHL
Damage later spreads to rest of the cochlea
Degeneration of the stria vascularis also occurs
Folate analog inhibitors indications
Methotrexate is in this class of drugs and used to treat
- Severe cancers of the blood, bone, lung, breast, head and neck, rheumatoid arthritis, psoriasis, and Cogan’s syndrome
- It is often given in conjunction with Vinblastine & Cisplatin
Folate metabolism is
Folate (natural form of vitamin B9) metabolism is fundamental to both cancerous and normal cells
True or False
Folate analog inhibitors are not ototoxic
FALSE
Highly ototoxic, especially in children especially if given with other cancer drugs, also nephrotoxic, and neurotoxic
Teratogenic and abortifacient (used in ectopic pregnancy)
Recommendation to wait 3 to 6 months after taking methotrexate to get pregnant
Folate analog inhibitors Limitations
Highly ototoxic, especially in children especially if given with other cancer drugs, also nephrotoxic, and neurotoxic
Teratogenic and abortifacient (used in ectopic pregnancy)
Recommended wait time for pregnancy after taking methotrexate
Teratogenic and abortifacient (used in ectopic pregnancy)
Recommendation to wait 3 to 6 months after taking methotrexate to get pregnant
Folate depletion and its resultant reduction of DNA synthesis is what?
Folate depletion and its resultant reduction of DNA synthesis is toxic to both malignant and normal cells
Inhibition of folic acid metabolism has been used as …
Inhibition of folic acid metabolism has been used as a mechanism for successful elimination of rapidly dividing cells, i.e., tumor cells
What is Methotrexate and what is it used for
Methotrexate is in the Folate analog inhibitors drug class
- Severe cancers of the blood, bone, lung, breast, head and neck, rheumatoid arthritis, psoriasis, and Cogan’s syndrome
Methotrexate Is often given in conjunction with what?
It is often given in conjunction with Vinblastine & Cisplatin
- Used in combination chemotherapy, often with Cisplatin
- Works by blocking mitosis, cell-cycle specific action
- Ototoxicity at higher doses
- Can be neurotoxic causing numbness, pain, & dizziness
Vinca Alkaloids
Vinca Alkaloids
Indications
Leukemia, lymphoma, breast & testicular cancer, in neuroblastoma combination therapy, and Kaposi’s sarcoma
What drug is used for Leukemia, lymphoma, breast & testicular cancer, in neuroblastoma combination therapy, and Kaposi’s sarcoma
Vinca Alkaloids
what cancer drug Is Generally administered IV
Metabolized in the liver and primary excretion is through the fecal route
Vinca Alkaloids
Vinca Alkaloids discriptors
- Used in combination chemotherapy, often with Cisplatin
- Works by blocking mitosis, cell-cycle specific action
- Generally administered IV
- Ototoxicity at higher doses
- Can be neurotoxic causing numbness, pain, & dizziness
Vinca Alkaloids indications
Leukemia,
lymphoma,
breast & testicular cancer, in neuroblastoma combination therapy, and Kaposi’s sarcoma
What is the most ototoxic antineoplastic drugs and why
Cisplatin (40-60%)
why
- Damage caused by free radical generation and inhibition of anti-oxidation processes
Permanent hearing loss is probably caused by
- Loss of OHCs in the basal turn initially resulting in earlier high frequency SNHL
- Damage later spreads to rest of the cochlea
- Degeneration of the stria vascularis also occurs
Hair cells and spiral ganglion neurons are the most susceptible to apoptosis (Cell death)
What medication class
- Relief of mild to moderate pain
- Reduction in inflammation
- Reduction in fever
- Prevention of stroke
Salicylates (aspirin)
Salicylates (aspirin)
indications
- Relief of mild to moderate pain
- Reduction in inflammation
- Reduction in fever
- Prevention of stroke
Drugs such as ibuprofen, naproxen, and ketoprofen
Therapeutic actions are similar to aspirin
Anti-inflammatory, analgesic, and antipyretic effects (reduce fever)
Other non-steroidal anti-inflammatory analgesics (NSAIDS)
Other non-steroidal anti-inflammatory analgesics (NSAIDS)
Drugs such as ibuprofen, naproxen, and ketoprofen
Therapeutic actions are similar to aspirin
Anti-inflammatory, analgesic, and antipyretic effects (reduce fever)
An antipyretic, primarily used for the treatment of malaria
Off-label use for benign nocturnal night cramps although not approved by FDA for that use (charley horse)
Quinine
Quinine
An antipyretic, primarily used for the treatment of malaria
Off-label use for benign nocturnal night cramps although not approved by FDA for that use (charley horse)
Acetaminophen indications
Useful for treating mild pain and fever but it is not an anti-inflammatory agent
Salicylates (aspirin)
toxicity
Ototoxicity
Tinnitus
Typically Reversible SNHL - (rarely permanent)
Other non-steroidal anti-inflammatory analgesics (NSAIDS)
Toxicity
All are nephrotoxic and also can affect the GI causing ulcers
Reversible tinnitus and hearing loss
They rarely cause significant or permanent SNHL
Quinine toxicity
Temporary ototoxicity and vestibulotoxicity
- Reversible bilateral high frequency SNHL with a characteristic 4000 Hz notch
- High pitched tonal tinnitus
- Dizziness/vertigo
Hallmark of acute toxicity especially in malarial patients is referred to as cinchonism and includes
- Tinnitus, hearing loss, dizziness, headache, nausea, and vision changes
Acetaminophen toxicity
No reported temporary or permanent ototoxic or vestibulotoxic effects
- hepatotoxic if taken in greater than recommended dosage
- Overuse or abuse of multi-ingredient substance like Vicodin, however, can cause rapidly progressive profound permanent SNHL
what is Vicodin
Vicodin is a combination of acetaminophen and hydrocodone
Diuretics indications
Primary therapeutic indications include
Hypertension, to reduce edema in patients with congestive heart failure, liver (cirrhosis), or kidney disease
Diuretics Toxicity
Not Ototoxic; Only loop diuretics are believed to be ototoxic
function of diuretics
All diuretics act the same way by preventing the reabsorption of sodium (salt) in the body
Which excretes water decreasing blood volume & pressure
- All are nephrotoxic
- can affect the GI causing ulcers
- Reversible tinnitus and hearing loss
- They rarely cause significant or permanent SNHL
Non-steroidal anti-inflammatory analgesics (NSAIDS)
Non-steroidal anti-inflammatory analgesics (NSAIDS)
ototoxic manifestations
- All are nephrotoxic
- can affect the GI causing ulcers
- Reversible tinnitus and hearing loss
- They rarely cause significant or permanent SNHL
- Show reversible biochemical and/or metabolic changes in cochlea with no permanent morphologic abnormality
- Tinnitus
High-pitched in the frequency of 6000 to 9000 Hz - Becomes louder with continued treatment and abates when treatment ends
- Reversible SNHL
Salicylates
Salicylates ototoxic manifestations
- eversible biochemical and/or metabolic changes in cochlea with no permanent morphologic abnormality
- Tinnitus
High-pitched - Becomes louder with continued treatment and abates when treatment ends
- Reversible SNHL
Temporary ototoxicity and vestibulotoxicity
- Reversible bilateral high frequency SNHL with a characteristic 4000 Hz notch
- High pitched tonal tinnitus
- Dizziness/vertigo
Quinine
Hallmark of acute toxicity especially in malarial patients is referred to as cinchonism and includes
Tinnitus, hearing loss, dizziness, headache, nausea, and vision changes
Quinine use
Quinine ototoxic manifestations
Temporary ototoxicity and vestibulotoxicity
- Reversible bilateral high frequency SNHL with a characteristic 4000 Hz notch
- High pitched tonal tinnitus
- Dizziness/vertigo
No reported temporary or permanent ototoxic or vestibulotoxic effects
- hepatotoxic if taken in greater than recommended dosage
- Overuse or abuse can cause rapidly progressive profound permanent SNHL
Acetaminophen
Acetaminophen
ototoxic manifestations
No reported temporary or permanent ototoxic or vestibulotoxic effects
- hepatotoxic if taken in greater than recommended dosage
- Overuse or abuse can cause rapidly progressive profound permanent SNHL
Loop Diuretics
ototoxic manifestations
- Dose-related, reversible depression of endocochlear potential and intra-labryrinth electrolyte changes
- Reduction in magnitude of the cochlear microphonics (CM)
- Recovery of cochlear potentials occurs gradually
- Reversible hearing loss if used alone
- Significant ototoxicity typically seen when given in high IV doses especially in conjunction with aminoglycosides
- The result can be rapid onset, flat, typically irreversible SNHL, with roaring tinnitus
Loop diuretics can also cause dizziness/vertigo
- Dose-related, reversible depression of endocochlear potential and intra-labryrinth electrolyte changes
- Reduction in magnitude of the cochlear microphonics (CM)
- Recovery of cochlear potentials occurs gradually
- Reversible hearing loss if used alone
- Significant ototoxicity typically seen when given in high IV doses especially in conjunction with aminoglycosides
- The result can be rapid onset, flat, typically irreversible SNHL, with roaring tinnitus
- Loop diuretics can also cause dizziness/vertigo
Loop Diuretics Ototoxic manifestations
What drug does this happen with?
Significant ototoxicity typically seen when given in high IV doses especially in conjunction with aminoglycosides
Loop Diuretics
The result can be rapid onset, flat, typically irreversible SNHL, with roaring tinnitus
How can blood thinners, bleeding disorders, and diabetes impact the management of an audiologic patient?
Small nicks can lead to severe bleeding
Especially important when making impressions, particularly deep canal impressions, and for cerumen management
Purpose for ototoxic monitoring per AAA (2009)
- Early detection so changes in the drug regimen may be considered
- audiologic intervention can occur
audiologic intervention for ototoxic monitoring?
Use of hearing aid and assistive devices
Programming hearing aids to adapt to changes in hearing sensitivity – progressive hearing loss
Educational support for children with hearing loss
True or false
Hearing loss may be unavoidable even with proactive ototoxicity monitoring
TRUE
hearing loss may be unavoidable even with proactive ototoxicity monitoring because the priority is effective management of the life threatening disease
ASHA criteria for clinically significant change in hearing sensitivity due to ototoxic medication
greater than a 20 dB pure-tone threshold shift at one frequency
greater than a 10 dB shift at two consecutive test frequencies
Threshold response shifting to “no response” at three consecutive test frequencies
Significant changes in hearing need to be confirmed within 24 hours
All threshold changes must be confirmed by retest
______ dB pure-tone threshold shift at one frequency is asha criteria for change in HS
greater than a 20 dB pure-tone threshold shift at one frequency
_______ dB shift at two consecutive test frequencies
is asha criteria for change in HS
greater than a 10 dB shift at two consecutive test frequencies
Threshold response shifting to “no response” at _____ consecutive test frequencies
is asha criteria for change in HS
Threshold response shifting to “no response” at three consecutive test frequencies
Significant changes in hearing need to be confirmed within _____
Significant changes in hearing need to be confirmed within 24 hours
All threshold changes must be ___________
is asha criteria for change in HS
All threshold changes must be confirmed by retest
Potential damage caused to the auditory system with radiation therapy
- potentially damage any of the auditory structures within the radiation field, extending from the external ear to the higher auditory pathways
- degrade the external ear and middle ear system
- 1/3 SNHL hearing loss
- cochlear microvascular fibrosis, in turn causing degeneration of OHCs, IHcs, and VIII N fibers
What type of hearing loss from radiation therapy?
present as conductive, mixed, sensorineural, or retrocochlear
How does radiation therapy degrade the external ear and middle ear system
Radiation therapy can degrade the external ear and middle ear system by **thickening of the tympanic membrane, stenosis of the ear canal, inflammation of the ET resulting in a temporary or permanent conductive hearing loss **
degrade the external ear and middle ear system by radiation therapy can result in what type of hearing loss?
temporary or permanent conductive hearing loss
cochlear microvascular fibrosis result of radiation therapy causes what?
causing degeneration of OHCs, IHcs, and VIII N fibers
Radiation HL is worse when in combination with ________
platinum-based chemotherapies
SNHL from radiation affects high frequencies more than low and results in
It is typically irreversible and progressive
It is typically considered a late adverse effect with onset occurring several years after treatment
Long-term (up to 10 years) audiologic follow-up post treatment is recommended
SNHL from radiation affects _____ frequencies more than ____ frequencies
SNHL from radiation affects the high frequencies more than the low frequencies
List Behavioral and physiologic tests used for ototoxic monitoring
Case history
Otoscopy
conventional audio
extended HF (EHF)
Tymp
Speech
OAE
ABR
what is EHF
High frequency audiometry
- can detect ototoxicity earlier than conventional
Tinnitus monitoring and why
- 40% of patients receiving chemotherapy develop tinnitus
- TOMI
what is the TOMI
Tinnitus monitoring interview
developed to detect tinnitus onset or chnages
ideally administered by and ENT or AUD
Pharmaceutical Cognitive Side Effects
- impaired concentration/ attention, disorientation, & confusion
- Loss of mental acuity, slowed thinking, & mental clouding
- Drowsiness & stupor
- Forgetfulness & dementia
Symptoms of what
- impaired concentration/attention, disorientation, & confusion
- Loss of mental acuity, slowed thinking, & mental clouding
- Drowsiness & stupor
- Forgetfulness & dementia
Pharmaceutical cognitive side effect can include
Pharmaceutical Cognitive side effects can result in
Poorer word recognition scores
Poorer pure tone threshold results
Difficulty following instructions
Poor compliance with use of hearing aids
for Vestibulotoxicity
_______ can happen if it is unilateral. ______ damage if bilateral
Compensation can happen if it is unilateral. Permanent damage if bilateral
Vestibulotoxicity monitoring requires
Monitoring requires assessment of the balance system including the vestibular reflexes such as vestibulo-ocular reflex (VOR) by caloric and rotary chair testing
Vestibulotoxicity treatment includes
Treatment can include
Medication
Vestibular rehabilitation therapy
Management of ototoxicity
- Counseling prior ototoxic drugs to make patients aware of potential ototoxicity
- Counseling patient and family after ototoxicity and recommending technology/aural rehabilitation
- Appropriate intervention
- Frequent follow up and counseling due to potential progressive loss and cognitive pharmaceutical adverse effects
Where is the primary damage occur for ototoxicity?
hair cells - Primary
Primary Target of NSAIDS
Kidneys, Nephrotoxics
what drug when in conjunction with gentamicin is ototoxic but when take alone is not?
Furosemide - Loop diuretic
What are the three primary toxcity reaction of aminogylcosides?
Nephrotoxity - Kidney
Neuromusulcar Blockade
Ototoxicity/Vestibulotoxity
Neuromuscular Blockade
Rare
non-depolarizing type of neuromuscular blockade that can lead to respiratory paralysis
Aminoglycoside Vestibular system toxcity
Type 1 hair cells are lost first casuing disturbances in vest function
Cochlear Hair cells are the primary target of what drug?
Aminoglycosides
Ototoxity Aminoglycosides
- Cochlear Hair cells are the primary target
- The Outer hair cells first from the base to the apex = HF SNHL
why does high frequency SNHL occur in Ototoxity w/ Aminoglycosides
- The Outer hair cells are destroyed first from the base to the apex resulting in HF SNHL
Amikacin, Gentamicin, Kanamycin, neomycin, streptomycin and tobramycin belong to what drug class
Antibiotics
Aminoglycosdies
Gentamicin shows high concentraion where?
Stria Vascularis
When should the OM baseline eval occur for chemotherapeutic drugs
The baseline evaluation should occur before or no later than 24 hours after administration of chemotherapeutic drugs
The baseline evaluation should occur before or no later than 24 hours after administration of _________
chemotherapeutic drugs
When should the OM baseline eval occur for Aminoglycoside antibiotics?
Before or no later than 72 hours following administration of aminoglycoside antibiotics
The baseline evaluation should occur Before or no later than 72 hours following administration of ___________
aminoglycoside antibiotics
A recheck of thresholds within ____ hours of the Baseline Test can be helpful for determining _______
A recheck of thresholds within 24 hours of the Baseline Test can be helpful for determining patient reliability
Monitoring Evaluation occur for Chemo
Monitoring Evaluations are performed:
* Periodically throughout treatment, usually prior to each dose for chemotherapy patients
Monitoring Evaluation occur for antibiotics
Monitoring Evaluations are performed:
* 1 to 2 times per week for patients receiving ototoxic antibiotics
What is a monitoring eval and it is dependent on what?
- Monitoring eval are a pared down version of baseline eval
- ME depends on patients drug regimen & physician recomendation
Monitoring and appropriate referrals for further auditory and vestibular testing also are warranted any time when patients’ report what?
Increased hearing difficulties
Tinnitus
Aural fullness
Dizziness
why do Ototoxic medication post-treatment
Because ototoxic hearing loss can be progressive, occurring > 6 to 12 months after drug regimen is discontinued
Time line for continuted Oto Monitoring after drug discontinuation
- For up to a year at 3,6,9 & 12 months
- Then anually thereafter for platinum based drugs
Summary of Ototoxic monitoring time line
- Baseline eval
- recheck of baseline
- Monitoring Eval
- Post treatment Monitoring
Specific times vary based on type
What is considered the most effective indicator of ototoxic HL
Detecting changes in puretone thresholds using serial audiograms is considered the most effective indicator of ototoxic HL
- Paricular when useing ultra HF thresholds are included
Why is OM important after drug discontinuation?
- Drug ototoxicity may occur days or weeks after use of ototoxic drugs - delayed onset
- Hearing loss may be progressive even after discontinuation of the drug
Progression after discontinuation is especially common with what drugs
Progression is especially common with aminoglycoside antibiotics and platinum-based chemotherapeutic agent
True or False
Monitoring Vestibular toxicity is good if you can but not that important since the vestibular system can compensate with minimal long term effects?
FALSE
damage caused by vestibular toxicity can result in compensation by the central vestibular system with minimal long-term effects, BUT in some cases the vestibular damage is permanent, especially if there is bilateral peripheral vestibular damage
How to conduct Vestibular Toxicity
Monitoring requires assessment of the balance system including the vestibular reflexes such as vestibulo-ocular reflex (VOR) by caloric and rotary chair testing
Treatments for Vestibular Toxicity
Treatment can include
Medication
Vestibular rehabilitative therapy
what is radiation therapy used for?
Cranial Radiation therapy is routinely used to treat a variety of brain tumors as well as head/ neck cancers in both children and adults
True or False
Radiation Therapy and hearing loss exhibit a dose reponse relationship
TRUE
as radiation dose incraeses so does the risk and degree of severeity of the hearing loss.
Timeline for post-treatment monitoring for radiation therapy
Long-term (up to 10 years) audiologic follow-up post treatment is recommended
Timeline for post-treatment monitoring for drugs
You typically monitor for over a year in 3 month periods and if there is no change you can stop monitoring
* 3 months, 6 months, 9 months, and 12 months
* Then annually thereafter, especially for platinum-based drugs
Potential damage caused to the auditory system with radiation therapy
- Any auditory structures within raditation field extending from external ear to higher auditory pathways
- degrade external ear and ME
- 1/3 SNHL
- Cochlear Microvascular Fibrosis
Cochlear Microvascular Fibrosis is a result of what?
Cochlear Microvascular Fibrosis is a result of radiation therapy.
* causing degenration of OHC,IHCs and VIII N fibers
SNHL from radiation exposure affects high frequencies more severely than low frequencies and it is….
- It is typically irreversible and progressive
- It is typically considered a late adverse effect with onset occurring several years after treatment
- Long-term (up to 10 years) audiologic follow-up post treatment is recommended
Radiation Therapy monitoring timeline
Radiation Therapy
Baseline Hearing Assessment: Before starting radiation therapy to establish a baseline for comparison.
Regular Monitoring: Typically, hearing should be monitored every 3 to 6 months during and after the completion of radiation therapy, depending on the risk factors and the specific treatment regimen.
Long-Term Follow-Up: Continued monitoring may be necessary for several years post-treatment, as radiation-induced hearing loss can sometimes develop or progress long after the treatment has ended.
