MAOI Flashcards
mao inhibitor is less commonly used due to what 3 side effects
hypotension
lethality of OD
lack of simplicity in dosing
what diet must be followed when taking an MAOI-causing what?
tyramine-free diet(causing systemic HTN)
if a patients do not respond to cyclic antidepressants - what can we give them
MAO inhibitors
how do we determine the dosing of MAO inhibitors
its not affected by age- young and old get the same amount- old have higher levels of MAO
what three maoi are approved in the US for depression or panic disorder
phenelzine
Tranylcypromine
Isocarboxazid
what MAOI is used for parkinson
Selegiline (MAO-B selective inhibitor). Formally known as deprenyl: has been shown to be effective in treatment of early Parkinson’s disease
where do you find MAO-A
platelets
60% found in the brain
where do you find MAO-B
placenta
MAO-B preferentially deaminates:
Phenylethylamine
MAO-A preferentially deaminates:
Serotonin
Norepinephrine
Epinephrine
what type of enzyme inhibition does MAO form- irreversible or reversible?
irreversible
where in the cell is MAO found
mitochondrial membrane
maoi moa
MAO in neurons are only capable of deaminating substrates that are free within the cytoplasm and are unable to gain access to substrates once they are bound in the storage vesicles.
Thus, cytoplasmic concentrations of MAO are maintained at low levels
what is the most common and serious side effect of MAOI- prominent in elderly
orthostatic hypotension
orthostatic hypotension may reflect accumulation of false neurotransmitters called?
octopamine- in the cytoplasm of postganglionic sympathetic nerve endings.
Phenelzine side effects
Phenelzine has anticholinergic like side effects and may produce sedation
Tranylcypromine side effects
Tranylcypromine has no anticholinergic side effects but has mild stimulant effects, which may cause insomnia
if patients complain of paresthesias during MAOI therapy what med can we give
pyridoxine therapy
Administration of “this” drug in combination with maoi may result in excitatory type 1 or depressive type II response.
meperidine
what three derivatives of meperidine has been associated with adverse reactions in patients treated with MAO inhibitors
fentanyl
sufentanyl
alfentanil
If a sympathomimetic is needed and the patient is taking an MAOI - do they need an direct acting or indirect acting
directing acting (phenylephrine) is preferable to an indirect acting drug. regardless of the dose- decrease about 1/3 of normal
what has been a suggested treatment for skeletal muscle rigidity and associated symptoms of hyper metabolism after an overdose with MAO inhibitors.
dantrolene
what is the recommendation for MAO inhibitors and stopping them for anesthesia
there is a growing appreciation that aneshtesia can be safely administered in most patients being chronically treated with mao inhibitor.
can patients on an MAOI have regional anesthesia?
if so can you use epi
it is acceptable but a cautious approach is not to add epinephrine.
is weight gain or weight loss associated with MAOI
weight gain
in contrast to tricyclic antidepressants- what does MAOI fail to produce
cardiac dysrhythmias
what medication is given to treat HTN with MAOI
nitroprusside
if cardiac dysrhythmias persist after control of systemic blood pressure what two meds can be administered
lidocaine and beta blockers
what two drugs can be administered to patients treated with MAOI having electroconvulsive therapy
etomidate and thiopental
what are the symptoms of serotonin syndrome
AMS, CLONUS, hyperthermia
what should be administered for serotonin syndrome
5ht2a- antagonist
