Oto Pharm Flashcards
Irreversible ototoxic drugs
Aminoglycosides, cisplatin, and maybe loop diuretics (furosemide)
MOA of ototox seen in aminoglycosides
Entry into outer hair cell through mechanoelectrical transucer channels -> formation of AG-Fe complex to form ROS -> Activation of JNK -> nucleus for increase in cell death pathway -> to mitochondria -> increase cytochrome c -> increase capsases and cases-independent apoptosis
MOA of cisplatin ototox
entry into outer hair cell -> formation of monohydrate complex -> activate NOX -> increase ROS -> activate JNK -> … -> apop via CAPSASE DEPENDENT MECH ONLY
MOA of ototox seen with furosemide (loop diuretics)
Block Na/K/2Cl channels also in ear= disruption of fluid balance with edema and loss of fx
T/F: Dose dependent ototox with aminoglycosides and loop diuretics
True
Which drugs are considered inappropriate for use in geriatric pts
Antihistaminergics aka Diphenhydramine, meclizine, and promethazine
Vertigo tx with longest duration
Scopalamine
Which antihistaminergic has a BBW for use by injection
Promethazine
AntiCHOLINERGIC used in vertigo that blocks M1 and stimulation of VIII
Scopalamine
Antihistamines utilized in vertigo affect which receptors
H1 and M1 (block)
Major receptors found in chemoreceptor trigger zone (CTZ).
Serotonin (5-HT), dopamine (D2), and opiods
Major receptors found in solitary nucleus tract (STN)
Enkephalin, histamine, Ach, and Serotonin (5-HT3)
3 phases of vomiting
Pre-ejection, retching, and ejection
Location of the central emesis center
Lateral reticular formation
How does CTZ monitor blood and CSF for toxic substances to trigger nausea and vomiting sensations through central emesis center?
Lack of BBB
Central emesis center receives information from what areas?
Gut (vagus n), CTZ, Cerebral cortex (anticipatory vomiting), and vestibular apparatus (motion sick)
Efferents from central emesis go where?
Nuclei in charge of salivation, respiration and vasomotor activity
Ex of serotonin antagonists
OndanSETRON, graniSETRON, dolaSETRON
ADE of Setrons
Hypersensitivity rxn, QT prolongation, interactions with CYP inhibitors
What drug increases the 5HT-3 blockage of setrons?
Dexamethasone
Most effective class of anti-emetics
Setrons (serotonin blockers)
T/F: D2 antagonists are for use in Chemo-induced NV
False
D2 receptor antagonism works at which part of the NV cascade
Chemoreceptor trigger zone
ADE with chronic use of Clor-azine
Bone marrow suppression and blood dyscrasias and QT prolongations
