stuff lecture 2 Flashcards
M1 (acts on what, second messengers?)
sweat glands, CNS
Gq/11, PLC, IP3, DAG, increase Ca increase NT release/ excitatory
M2
Heart, SM, presynaptic
*stim Gi, inhibits adenylyl cyclase, inhibits cAMP/ inhibitory
M3
exocrine, SM, endothelium
Gq/11, PLC, IP3, DAG, increase Ca, increase NT release
Nicotinic
Na gated ion channel, Nn (brain and autonomic ganglia) and Nm (skeletal m), excitatory
- brain, adrenal medulla, autonomic ganglia, NMJ
- rapid desensitization
Alpha1
SM, excitatory
Gq, PLC, IP3, DAG, increase Ca, increase NT
alpha 2
presynaptic nerve terminal, some SM
Gi, inhibits adenylyl cyclase, inhibits cAMP
all beta receptors
stimulate Gs, stim adenylyl cylase, stimulate cAMP
B1
heart, increases rate and force
stim Gs, stim adenylyl cyclase
B2
bronchioles, heart, smooth m in skeletal blood vessel (vasodilation)
stim Gs, stim adenylyl cyclase
B3
lipolysis in fat cells
stim Gs, stim adenylyl cyclase
D1, 5
brain and vascular bed
ususally stim Gs, stim adenylyl cyclase, increase cAMP
D2,3,4
Brain and OTHER tissue
stim Gi, inhibits adenylyl cyclase, decrease cAMP
M2 on heart
decelerates SA node, decreases atrial contractility
M3 on eye
contracts iris circular m, contracts ciliary muscle
a1 on eye
contracts iris radial m
B on eye
relaxes ciliary m
B1 on heart
accelerates SA node, accelerates ectopic pacemakers, increases contractility
B2 on heart
accelerates SA node, accelerates ectopic pacemakers, increases contractility
alpha on skin, skeletal BV
contracts BV, contracts skeletal m BV
B2 on skeletal BV
relaxes (vasodilation)
M3, M5 stimulation by drug on BV
releases NO, vasodilation
B2 on lungs
bronchodilation
M3 on lungs
bronchoconstriction
a2 on GI
relaxes SM walls
B2 on GI
relaxes EM wall
a1 on GI
contracts sphincters
SNS on GI secretion
na
M3 on GI
contracts SM walls, relaxes sphincters, increases secretion
B2 on GU
relaxes bladder wall, relaxes uterus preg
PNS on BV
na (except indired NO release via M3 stimulation)
PNS (M) on GU
erection
a1 on GU
contract sphincter
SNS on GU
ejaculation
M3 on GU
contract bladder wall, relax sphincter
SNS (a) on pilomotor SM
contracts
M on eccrine sweat glands
increase secretion
a on apocrine/stress sweat gland
increases secretion (a for apocrine)
B2 on metabolic function
gluconeogenesis and glycogenolysis in liver
a on metabolic function
gluconeogenesis and glycogenolysis in liver
B3 on metabolic function
lipolysis on fat cells
B1 on metabolic function
renin release in kidney
Direct Cholinergic agonists (M agonists)
ACh, Methacholine, Carbachol, Bethanechol (all esters, quaternary) then Pilocarpine and cevimeline
Direct Cholinergic agonsts (N agonists)
Nicotine, varenicline (varenicline is partial N agonist in brain)
M agonist activity on Brain
improve memory, alertness and arousal
tx: alzheimers
therapeutics M agonist eye
Glaucoma (pilocarpine)
- revere narrow angle glaucoma attack
- cause blurred vision, drug of last choice
Muscarinic/cholinergic SE
mushroom/muscarine poisoning: salivation, N/V, HA, visual disturbances, bronchospasm, bradycardia, shock
tx: atropine (M antag) and albuterol (B2 agonist)
contraindication M agonist
PUD, asthma/COPD, bowel obstruction
N stimulation in brain
low dose = alert
high = tremor, emesis, increased respiraiton
toxic = convulsion
N stim in ganglia (Nn)
activates SNS and PNS
SNS: HTN, tachycardia alt with vagal bradycardia
PNS: N/V, diarrhea, urination
N stim at NMJ
muscle twitch/contraction then depolarizing block/paralysis aka desensitization
tx N toxicity
Atropine (block M, decrease PNS)
anticonvulsants
assist respiration
Cholinesterase inhibitors
Neostigmine (quarternary), Physostigmine (tert), Edrophonium, OP (DFP, Echothiphate, Soman, Sarin, Parathion, Malathion)
what are the carbamates of ACHe inhibitors
Neostigmine, Physostigmine
*covalent bond, 30min - 6 hr
slow AChE hydrolysis
Edrophonium vs OP
Edro reversible and short acting 5-10 min, inject
OP: long lasting, phosphorylate AChE can be irreversible so prevent with 2PAM
AChE inhibitor on CNS
alert, improve memory, convulsion, respiratory arrest
AChE inhibitor on heart
*all ganglia activated
* in heart, PNS dominates (ganglia and M receptor stim) –> bradycardia, decrease contractility, decrease CO
BP: little effect bc no cholinergic innervation
AChE at NMJ
low concentration: intensify/prolong ACh action, increase muscle strength (neo tx myasthenia)
high: twitches, fasiculation, NMJ block, paralysis
Echothiophate
OP AChE inhibitor, quaternary, EYEDROP, long duration action, decrease IOP tx narrow angle glaucoma
soman, sarin, tabun
OP AChE inhibitor - n gases, more potent and faster than DFP
Glaucoma tx
direct M agonist (pilocarpine, carbachol) or AChE inhibitor (physostigmine, echothiophate) - SE bc activate ciliary m; near vision accomodation
Reversal of NMJ block
use AChE inhibitor ie neostigmine
AChE inhibitor toxicity
SLUDGE, bradycardia, hypotension, convulsion, NMJ stimulation then paralysis
OP AChE inhibitor toxicity tx
atropine til pupils dilate, 2PAM, respiration, Diazepam for convulsion
Carbamate (neostigmine, physostigmine AChE poisoning)
Carbaryl
Propoxur
Aldicarb
2PAM controversial
antimuscarinic (anticholinergic) drugs aka M antagonists
atropine, scopolamine tropicamide (eye), homatropine (eye) Ipratropium, tiotropium inhaled (lung) Dicyclomine (anti GI spasmodic) Lomotil (atropine +opiod tx diarrhea) Tolterodine, sarifenacin, darifenacin, fesoteridine, solifenacin, oxybutynin, trospium (bladder)
atropine absorption, scopolamine absorption
both good orally
atropine in CNS only at high dose
Scopolamine CNS easily (sedation, euphoria, amnesia) - motion sickness patch
effect of atropine on tissue related to dose
low: salivary, sweat gland, bronchiole
medium: heart, eye, GI, GU
high: CNS
anti M and parkinsons
antimuscarinics sometimes used for parkinsons
scopolamine on CNS
drowsiness, memory loss, relieves motion sickness, dies up secretion (pre-anesthetic)
toxic: hallucinations, agitation, coma
M antagonist on eye
block iris circular m, mydriasis but inhibits ciliary so inhibits near vision, cycloplegia, photophobia, dry eyes, can cause narrow angle glaucoma!
*tropicamide, homatropine
Normal conditions cholinergic input on heart vs with post-synaptic M2 antagonist/block
cholinergic input stimulate M2 receptors in atria, SA/AV node (no BP control)
*PRESYNAPTIC M2 RECEPTORS DECREASE NE RELEASE thus HR is DECREASED aka VAGAL TONE
so if give M2 antagonist like atropine, vagal tone will be inhibited, NE should increase, HR should increase aka TACHYCARDIA (slide 74 lecture 2)
post-synaptic M2 antagonist on heart rate and BP
increase NE bc M2 blocked, decreased vagal tone (vagal tone predominates in normal conditions), less vagal tones means TACHYCARDIA
little effect on BV bc no cholinergic stimulants BUT since M3 stim can cause NO release (and thus vasodilation), blocking the M receptor prevents NO release and thus blocks vasodilation caused in response to M agonists
What affect might atropine OD have on the face
may cause vasodilation of face bc major route of perspiration is blocked, and if atropine is used excessively, perspiration (an M stimulated response) is inhibited (atropine is M antagonist). This inhibits heat loss via perspiration so the body responds by vasodilating the BV in face to decrease heat
overactive bladder meds
M3 antagonists (tolterodine, darifenacin, solifenacin, oxybutynin, trospium)
*ocybutynin, tospium preven bladder spasm after prostrate surgery
how to remember the M antagonists
Mean antagonists. A troop gladly scoped [out] Ipra’s tios home. The cyclone totally loaded Sarah’s sole troubled ox.
meaning: Mean antagonists (M antagonists). A (atropine) troup (tropicamide) gladly (glycopyrrolate) scoped (scopolamine) [out] ipra's (ipratropium) tios (triotropium) home. (homatropine) The cyclone (dicyclomine) totally (tolterodine) loaded (lomotil) Sarah's (sarifenacin) sole (solifenacin) troubled (trospium) ox (oxybutynin)
M antagonist - cardiac uses
ATROPINE: decrease bradycardia due to vagal tone, reverse heart block, after MI
GLYCOPYRROLATE: in surgery to prevent excessive vagal reflexes
M antagonist - Respiratory uses
IPATROPIUM (ATROVENT) or TIOTROPIUM (SPIRIVA):
improved breathing in COPD by blocking bronchoconstriction, some asthma help
M3 antagonist - overactive bladder use
Tolteridone, fesoterodine, darifenacin, solifenacin: *promote continence; SE dry mouth, blurred vision
M antagonist - post surgery bladder
Oxybutynin, trospium:
- prevent bladder spasm after prostate survery by blocking muscarinic influence on bladder tone and spasm
- dry mouth main SE
contraindications to using M antagonists
narrow angle glaucoma, BPH
SE: dry mouth, decrease bronchial secretion, tachycardia, mydriasis, cycloplegia, decreased GI motility, urinary retention, dry kin, decreased sweating
Atropine OD and tx
dry as a bone, blind as bat, red as a beet, mad as a hatter
tx: AChE inhiitor (pysostigmine)
other drugs with anticholinergic effects to beware of for M antagonist OD
antihistamine (benadryl), TCA, antipsych, plants, eyedrops, anti-diarrheal prep
What types of NMJ blockers are there and what do they do?
block N receptor on skeletal m; used to produce paralysis during surgery
- depolarizing: stim before blockade
- non-depolarizing: competitive antagonist, produce direct block
How does Succinylcholine (a depolarizing NMJ blocker) work
two succ bin Nicotinic NMJ receptor, top gat opens, sodium flows through then time dep gate closure, channel BLOCKED
*depolarizes before blocking, initial contraction before paralysis; brief action, rapid onset
how does non depolarizing block work
block receptor, prevent ACh effect (inhibit muscle contraction), competitive reversible, used in surgery to relax muscle
*AChE inhibitor used to reverse effect
ganglion receptor blockers mode of action
block N receptor at autonomic ganglia, decrease ANS output, non depolarizing competitive antagonists
*once used to tx HTN, not used now much
what are the ganglion blockers
hexamethonium
mecamylamine (competitive blocker, enters CNS, sedation, mental status affected, mvmt affected
hexamethonium man
pink, pale, warm dry, placid can’t cry, doesn’t blush or get pale, doesn’t sweat,wears a corset and may fidget, dry mouth and throat, far sighted, blinded by light, eyes are red, doesn’t belch, feels the cold, good BP, no ulcers, no hunger pangs, stomach doesn’t rumble, constipated, urinary retention and impotence
SNS
Ganglion blockers affect on body systems
mostly SNS: cycloplegia, mydriasis, vasodilation, decreased vagal tone, orthostatic hypotension, contractility blocked, decreased vagal tone - tachycardia, bladder tone decreased, urinary retention, erection/ejaculation reduced, no sweating
review
slides 100-111 on NMJ block