Nervous system/drugs Flashcards
Parasympathetics
- Parasympathetics use neurons that are cholingergic (that is, ACh is the main neurotransmitter)
- Pelvic splanchnic nerves and CN lll, Vll, lX, X
- M2 (inhibitory) decrease HR and contra filing of atria
- M3 (q) bladder contraction
Sympathetics
- Sympathetics use neurons that are adrengergic use Epinephrine and NE as the main neurotransmitters)
- Sweat glands are part of sym. Pathway but are innervated by cholinergic fibers
- a1 -phospholipids C,protein kinase C, ca2+=smooth muscle contraction.
ACh receptors
Nicotinic ACh receptors are Ligand-gated Na+/K+ Channels: Nn (found in autonomic gangia, adrenal medulla) and Nm (neuromuscular junction in skeletal muscle)
direct cholingeric drugs
Bethanechol
Carbachol
Methacholine
pilocarpine
indirect cholinergic drugs
- parasympathetic
- donepezil, rivastigmine, galantamine
- edrophonium
- neostigmine
- physostigmine
- pryidostigmine
Bethanochol
- No nictotinic activity
- Resistant to AChE
- Activates Bowel and bladder
- uses:Postoperative Joey’s, neurogenic Josh’s, urinary retention.
Anti cholinergic drugs
- atropine
- anti dumbbelss
- sympathetic; cant see, pee or shit.
Alzheimer’s drugs
Donepezil
Rivastigmine
Galantamine
Neostigmine
- No CNS penetration
- used to reverse neuromuscular blockade (post op)
Physostigmine
- PHreely Crosses BBB (tertiary amine)
- antidote (Phyxes) for atropine overdose
Pyridostigmine
-Increases muscle strength
Organophosphates
- Irreversibly inhibit AChE = DUMBBELSS
- Antidote is atropine (competitive inhibitor) + pralidoxime (regenerates AChE if given early)
Pralidoxime
-Regenerates AChE
Atropine
- Dilates eye
- Cycloplegia (paralysis of ciliary muscle leading to loss of accommodation)
Fenoldopam
- D1
- Promotes Natriuresis
Isoproterenol
- Can worsen ischemia
- B1=B2
- Reflex tachycardia (vs Norepinephrine)
- Decreased MAP
- Unopposed B2
Norepinephrine
- Reflex bradycardia
- a1>a2>B1
- Unopposed a1
Phenylephrine
- a1>a2
- Used for ocular procedures to dilate eye.
- Ischemic priapism (pain and rigidity of penis)
A1 stimulator drugs
Midodrine
Phenylephrine
Norepinephrine
Mirabegron
- B3
- Used in urinary urge incontinency/overactive bladder (sudden urge to urinate followed by involuntary loss of urine)
Albuterol, Salmeterol, terbutaline
- B2 > B1
- Albuterol used for acute asthma or COPD.
Terbutaline
-Acute bronchospasm in asthma and tocolysis (anti-contraction to prevent premature labor)
Salmeterol
- Long term asthma
- COPD management
Anti-sympathetics
- AKA a2 agonists
- Anti-hypertensive drugs
- Clonidine, guanfacine
- a-methyldopa
- tizanidine
Clonidine
Guanfacine
- Used in hypertensive urgency
- Symptoms control in opioid withdrawal
- Rebound hypertension with abrupt cessation .
A-methyldopa
- HTN in pregnancy
- Side effect: Direct Coombs + hemolysis
Tizanidine
- Relief of spasticity
- Side effect: xerostomia (dry mouth)
Alpha blockers
-Non-selective: Phenoxybenzamine Phentolamine -a1 selective: Prazosin, terazosin, Doxazosin, tamsulosin -a2 selective: Mirtazapine
Phenoxybenzamine
- Irreversible
- non selective alpha blocker
- SE: reflex tachycardia and orthostatic hypotension
Phentolamine
- Reversible
- non-selective
- cocaine induced HTN
- patients taking MAO inhibitors who eat tyramine containing foods.
- SE: reflex tachycardia and orthostatic hypotension.
Selective a1 blockers
Tamsulosin
Terazosin
Doxazosin
Prazosin
Tamsulosin
- Not given in HTN like other a1 blockers.
- 1st-dose orthostatic hypotension
Prazosin
- Used in PTSD
- Urinary symptoms of BPH
- 1st-dose orthostatic hypotension
Doxazosin side effects
-SE: dizziness, headache, 1st-dose orthostatic hypotension
Selective A2 blockers
Uses and Side effects
-Mirtazapine:
Uses:
-Depression
SE:
- increased cholesterol
- Increased appetite
- Sedation
BP response to epinephrine and when adding alpha blockade
-Epinephrine is b > a so when adding alpha blocker there is unopposed beta action:
B1: reflex tachycardia
B2: reversal of MAP from net increase to a net decrease.
BP response to phenylephrine and when adding alpha blockade
- a1 > a2
- Phenylephrine is a PURE alpha agonist therefore response is suppressed but NOT reversed (lacks beta agonist properties)
Selective B1 blockers
- A to M
- Acebutolol (partial agonist)
Non-selective B blockers
- B1 > B2
- N to Z; nadolol, pindolol (partial agonist), propranolol, timolol
Both alpha and beta blockers
- Carvedilol
- Labetalol
Nebivolol
-Combination of B1 (cardiac selective) blockade with B3 blockade (increases NO and decreased SVR)
Anti-cholingergic, drugs that treat irritable bowel syndrome anti- spasmodics.
Hyoscyamine
Dicyclomine
Cholinergic drugs affect on bladder and GI
- Contracts bladder (treats urinary retention; bethanechol, neostigmine)
- Contacts gut (treats ileus; lack of movement in the intestine leading to build up of stuff; neostigmine and bethanochol)
Ingested seafood
- Histamine (scombroid poisoning)
- Ciguatoxin
- Tetrodotoxin
Pufferfish
- Tetrodotoxin
- Puffer Prevents depolarization
- Blocks fast voltage gated Na+ channels
- loss of reflexes
Histamine (scombroid poisoning)
- spoiled dark meat fish
- mahi mahi, tuna, mackerel bonito
- bacterial histidine decarboxylase converts histidine to histamine.
- mimics anaphylaxis;flushing, burning sensation in mouth, angioedema, bronchospasm
Ciguatoxin
- reef fish; barracuda, snapper, moray eel
- Cigua Causes depolarization
- Perioral numbness
- reversal of hot and cold sensations,
Argus to avoid in elderly patients (BEER CRITERIA-due to decreased efficacy or increased risk of adverse effects)
- A-BLOCKERS (hypotension)
- anticholingergics, antidepressant, antihistamines, opioids (delirium, sensations, falls, constipation, urinary retention)
- PPI’s, NSAIDS, Benzos
Acetaminophen toxicity antidote
N-acetylcysteine (replenishes glutathione)
AChE inhibitors, organophosphate toxicity antidote
Atropine > Pralidoxime
Arsenic toxicity antidote
Dimercaprol, succiner
Benzodiazepines antidote
Flumazenil
Carbon monoxide antidote
100% oxygen, hyperbaric oxygen
Copper toxicity antidote
Penicillamine, Trientine
Cyanide toxicity
Nitrite, thiosulfate, hydroxocobalamine
Digitalis toxicity
Anti-dig Fab fragments
Heparin toxicity antidote
Protamine sulfate
Iron antidote
Dexferoxamine, deferasirox, deferiprone.
Lead antidote
EDTA, Dimercaprol, succiner, penacilllamine
Mercury antidote
Dimercaprol, succimer
Methanol, ethylene glycol (antifreeze)
Fomepizole > ethanol, dialysis
Methemoglobin
Methylene blue, vitamin C (reducing agent)
Opioids
Naloxone
Salicylates
NaHCO3 (alkalyzes urine), dialysis
TCA’s
NaHCO3 (stabilizes cardiac cell membrane)
Warfarin
Vitamin K (delayed effect) fresh frozen plasma (immediate)
