Neuro pharmacology

Section 1

Question	Answer
epinephrine	alpha agonist. decreases aqueous humor synthesis due to vasoconstruction
epinephrine SE	mydriasis, stinging, done use in closed angle
bromonidine	alpha blocker, drecreses aqueous humor synthesis
timolol, betatocolol, carteolol	beta blockers, decrease aqueous humor secretion
acetezolamide	decrease aqueous humor secretion du to decreased HCO3-
pilocarpine, carbachol	direct cholinomimetic. increases outflow of aqueous humor, contracts ciliary mucsle and opens trabecular meshwork.
physostigmine, echothiophate	indirect cholinomimetic increases outflow of aqueous humor, contracts ciliary mucsle and opens trabecular meshwork.
cholinomimetics SE	miosis, cyclospasm
use in emergency	pilocarpine. v. effective at opening meshwork into canal of schlemm
latanoprost	PGF2alpha. increases outflow of aquesous humor.
prostaglandin side effects	darkens color of iris
	memorize

Opioid analgesics

 

Question	Answer
opioids	morphine, dextromethorphan, meperidine, methadone, heroin, codeine, fentanyl
opioids mechanism	open K channels, close Ca chennel at recepttior to modulate synaptic transmission. inhibit release of ach, 5ht, ne, glutamate, substance p
binds at mu	morphine
binds at delta	enkephalin
binds at kappa	dynorphin
opioid uses	pain, cough suppression, diarrhea, acute pulmonary edema, maintanance for addicts
opioids for diarrhea	loperimide and diphenoxylate
toxicity and tx	resp depress., pinpoint pupils, CNS depress. Tolerance does NOT develop for miosis and constipation
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Question	Answer
butorphanol mechanism	partial agonist at mu receptiors, agonist at kappa
butorphanol uses	pain, causes less respiratory depression than full agonists.
butorphanol	causes withdrawal if patient is on full agonist
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tramadol mech : very weak agonist, also inhibits 5ht and NE uptake

Question	Answer
tramadol use	chronic pain
tramadol SE	similar to opiods, decrease seizure threshold(TRAMatic)
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Epilepsy drugs

phenytoin

Question	Answer
phenytoin mechanism	use dependent blockade of na channels, increasing the refractory period. inhibits glutamate release from excitatory presynaptic neurons.
phenytoin uses	tonic clonic siezures, IB antiarrythmic
phenytoin SE	nystagmus, ataxia, diplopia, sedation, SLE, induces p450. gingival hyperplasia in kids(w/ chronic use), periph. neurop., hirsutism, megaloblastic anemia(decrease folate absorption), teratogen
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drugs

Question	Answer
carbamazempine	increases sodium cahnnel inactivation.
sarbamazepine uses	1st line for tonic clonic, also 1st line for trigeminal neuralgia
carbemazapine SE	diplopia, ataxia, blood dyscrasias- agran, aplastic anem, liver tox, tertaogen, induction of p450, SIADH, stevens johnson
lamotrigine mech and use	blocks voltage gated na channels. simple, partial, tonic clonic
lamitrogine SE	stevens johnson syndrom
gabapentin mech	desgined as GABA analog, but primarily inhibits HVA(hi volt. activated) calcium channels. peripheral neurop, bipolar disorder
topiramate mech an use	blockes sodium channels, increase GABA action, simple partial, tonic clonic
gabapentin SE	sedation, ataxia
topiramate SE	sedation, mental dulling, kidney stones, weight loss
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drugs cont'd

 

Question	Answer
valproic acid mech	increase na channel inactivation, increase GABA conc
valprioc uses	1st line for tonic clonic, also use in absense, also for myoclonic
valproate SE	gi distress, rare but fatal hepatotox, (measure LFT), neural tube defects in fetus, tremor, weight gain, contraindicated in preg
phenobarb SE	sedation, tolerance, dependence, induction of p450
ethosuximide mech	blocks thalamic t-type Ca channels
ethosuximide uses	only first line for absense
ethosuximide SE	GI distress, fatigue, headache, urticaria, stevens johnson
tiagibine mech	inhibits GABA reuptake
vigabatrin mech	irreversible inhibits GABA transaminase so increases GABA
levetiracetam mech	unknown, may modulate gaba and glu release
for absence siezures	valprotate, ethosuximide
1st line status propylaxis	phenytoin
1st line for acute status	benzo
1st line for tonic clonic	phenytoin, carbemazipine, valproic
drugs that inactivate sodium channels target sodium channels	-Phenytoin -Carbamezepine -Lamotrigine -topiramate -Valproic acid
drugs that increase GABA action/concen or decrease reuptake or breakdown	action/ concen: Topiramate - Valproic acid vs reup/breakdown: -Tiagabine -Vigabatrin
	memorize

Benzos

Question	Answer
drugs	end in __pam, __lam; chlordiazepoxide
benzodiazapenes mechansim	increases GABA action by increasing frequency of Cl- channel opening= FREnzodiaepines(increase frequency). decreases REM sleep
benzo uses	anxiety, spasticity, status epilepticus(lorazepam & diazepam), detox(fights withdrawal sx), night terrors, sleepwalking, anesthetic, hypnotic, eclampsia(even tho 1st line is Mg SO4)
benzo SE	dependence, additive CNS depression with etoh.
benzo od tx	flumezanil- competitive antagonist at GABA receptor(ligand-gated Cl- channel) for this drug.
Short-acting	Triazolam, Oxazepam, Midazolam= TOM thumb: highest addictive potential
	memorize

NonBenzodiazepine hypnotics

Question	Answer
drugs	Zolpidem, zaleplon, eszopiclone
MoA	act via the BZ1 receptor subtype
what can reverse their effects	flumazenil
clinical use	insomnia
toxicity	ataxia, headaches, confusion. short duration bc of rapid metab. by liver enzymes BUT low dependence compared to benzo's
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barbituates

Question	Answer
barbiturates	phenobarbitol, thiopental, pentobarbital, secobarbital
phenobarbital mech	increases GABA- action
phenobarbital uses	1st line in pregs and children
bariturates mech	facilitate GABAa action by increaseing duration of Chloride opening, so decreasing firing.
barbiturare uses	sedative for anxiety, siezures, insomnia, induction of anesthesia
bariturates SE	dependence, additive CNS effects with etoh, rep or cardio depression, drug interactions owing to induction of p450
bariturate OD	symptom management.
barbiturate contraindication	porphyria(rare inherited or acquired disorders of certain enzymes that normally participate in the production of porphyrins and heme. They manifest with either neurological complications or skin problems, or occasionally both.)
	memorize

Anesthetic gen principles

what must CNS drugs be to cross BBB : lipid soluble

Question	Answer
drugs with decreased solubility in blood mean	rapid induction and recovery
drugs with increased solubility in blood mean	increased potency
MAC	minimal alveolar concentration at which 50% of the population is anesthetized. inversely related with potency
mechanism of anesthetics in lungs	increased rate + depth of ventilation= increased gas tension
increased blood solubility and blood/gas partition coefficient means	increased amount of drug needed to saturate blood and slower onset of action
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inhaled anesthetics

Question	Answer
inhaled anesthetics	halothane, enflurane, isoflurane, sevoflurane, methozyflurane, NO
inhaled anesthetic effects	myocardial depression, resp depression, nausea and emesis, increased cerebral blood flow because of decreased cerebral metabolic demand
halothane tox	hepatotox
methoxyflurane tox	nephrotox
enflurane tox	proconvulsant
nitric oxide tox	expansion of trapped gas.
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IV anesthetics

Question	Answer
IV anesthetics	barbiturates, propofol, benzo, arylcyclohexylamines(ketamines), opiates= B.B King on OPIATES PROPOses FOOLishly
thiopental	high potency high lipid sol, rapid entry to brain. induction of anesthesia and short procedures.
termination of thiopental	rapid redistribution into tissue and fat
midazolam	mc used for endoscopy adjunctively with gas and narcotics. can cause depress.in resp and BP use flumazenil for OD
ketamine	Arylcyclohexylamines= PCP analog that acts as dissasocative anesthetics. blocks NMDA receptor. CV stimulant. disorientation, hallucination, bad dreams
propofol	used for rapid anesthesia induction and short procedures. ~less post op nausea than thipental. potenitaes GABA....don't give to POP stars for home use!!!!!!!!!!!!
	memorize

local anesthetics

Question	Answer
local anesthetics	procaine, lidocane, tetracaine, (amides lidocaine, mepivacaine, bupivicaine: amides have two I's)
local amides mech	block na channels by binding to specidic receptors on inner portion of channels. preferentially bind to activated Na channels so most effective in rapidly firing nerons. teriarys penetrate membrane in inchance dfrom then bind in charged form
in infected tissue?	need more anesthetic because its harder for bases to penetrate acidic tissue( bc they are charged and can't penetrate membrane)
local anesthetic esters	procaine, cocaine, tetracaine
local anesthetic amides(given when allergic to esters)	lidocaine, mepivicaine, bupivicaine
local anesthetic tox	CNS excitation, hyperthension, hypotension
bupivicaine tox	severe cardio tox
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local anesthetic cont'd

Question	Answer
first nerve to get blocked	small myelinated
last nerved to ge blocked	large unmyelinated
which factor predominates as far as nerve blockage size or myelination	SIZE
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NM blocking drugs

Question	Answer
neuromuscular drugs	muscle paralysis in surgery or mechanical ventilation. selective for motor vs. auto nicotinic receptor
depolarizing neuromuscular drug and it's S/E	succinylcholine= hypercalcemia and hyperkalemia
reversing phase 1 succinylcholine block	no antidote!!!!!!! . cholinesterase inhibitors makes it worse
reversing phase 2 block	cholinesterase inhibitor
phase 1 block	prolonged depolerization
phase 2 block	repolarized but still blocked
	memorize

NM blocking drugs cont'd

Question	Answer
Nondepolarizing neuromuscular drug	tubocurarine, atracurium, mivacurium, pancuronium, vecuonium , rocuronium
nondepol neuromuscular drug mech	compete with Ach for receptors
reversing non depol drug block	neostigmine, edrophonium, and other cholinesterase inhibitors
	memorize

Dantrolene

Question	Answer
dantrolene use	malignant hyperthermia, neuroleptic malignant syndrome(toxicity of antipsychotic)
dantrolene mechanism	prevents release of calcium from SR of skeletal muscle
What causes malignant hyperthermia?	inhalation anesthetics(except N2O) and succinylcholine
	memorize

Parkinson's disease drugs

Question	Answer
main problem in PD?	decrease dopamine and excess cholinergic activity
dopamine agonists	bromocriptine(ergot), pergolide, pramipexole, ropinirole= non-ergot preferred
increase DA	amantidine( also used as antiviral), L DOPA/carbidopa
prevent DA breakdown	selegiline, entacopone, tolcapone
silegilene	selective MAOI type B inhibitor. type B selects DA over NE and 5-HT
COMT inhibitors	entacopone, tolcapone. prevent L-dopa degradation
curb excess cholinergic activity, antimuscarinic, improves tremor and rigiditiy but not bradykinesia	benztropine
main players in PD treatment	BALSA= Bromo,Ama, Levo, Sele, Antimuscarinic
	memorize

L-DOPA/carbidopa

Question	Answer
LDOPA/carbidopa	increase DA in brain. tox is arrhythmias from peripheral conversion to dopamine. longterm use can lead to dyskinesia, and akinesia between doses.
increase bioavailability of da in brain and limit peripheral SE	carbidopa
	memorize

Alzheimer's drug

Question	Answer
Memantine mechanism	NMDA receptor antagonist. helps prevent excitotoxicity(mediated by Ca2+). alz drug
donezapil, galantamine, rivastigmine and S/E	Achase inhibitors....nausea, dizziness,insomnia
	memorize

Huntington's drugs

Question	Answer
HD	increase dopamine, decrease GABA+Ach
Reserpine and Tetrabenzine	amine depleting huntington's drug
haloperidol	da receptor antag, huntingtons
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Sumatriptan

Question	Answer
supatriptan mec	5-HT agonist. causes vasoconstriction and inhibition of trigemenial activation and vasoactive petide release. half life is less than 2 hours
sumatriptan use	acute migraine, cluster headache attacks= a SUMo wrestler TRIP's ANd falls on your head
sumatriptan tox	coronary vasospasm contraindicated in patients with CAD or prinzmetal angina. mild tingling
	memorize