First Aid pharmacology Flashcards
TD50/ED50
safer drugs have higher TI values
Examples of drugs with low TI values
digoxin, lithium, theophylline, warfarin
Sweat glands and adrenal medulla are innervated by what?
sympathetic nervous system; cholinergic nerve fibers
Nicotinic Ach receptors ligand gated Na/K channels. what are the 2 receptors, where are they found
N(N) autonomic ganglia; N(M) (neuromuscular junction)
What type of receptors do muscarinic Ach act through?
G protein coupled receptors . M1-5
qiss qiq siq sqs
alpha 1, alpha2, beta1, beta 2, M1, M2, M3, D1, D2, H1, H2, V1, V2
alpha 2
decrease sympathetic outflow, decrease insulin release, decrease lipolysis, increase platelet aggregation
beta 2
vasodilation, bronchodilation, increase heart rate, increase contractility, increase lipolysis, increase insulin release, decrease uterine tone (tocolysis), ciliary muscle relaxation, increase aqueous humor production
M1
CNS, enteric nervous system
M2
decrease HR and contractility of atria
M3
increase exocrine gland secretions (lacrimal, salivary, gastric acid), increase gut peristalsis, increase bladder contraction, bronchoconstriction, increase pupillary sphincter contraction (miosis), ciliary muscle contraction (accomodation)
D1
relaxes renal vascular smooth muscle
D2
modulates transmitter release, especially in brain
H1
increase nasal and bronchial mucus production, increase vascular permabliity, contraction of bronchioles, pruritis, and pain
H2
increase gastric acid secretion
V1
vascular smooth muscle contraction
V2
H20 permability and absorption in the collecting tublus of the kidney (V2 is found in the 2 kidneys)
Metyrosine
blocks conversion of tyrosin to DOPA
Reserpine
blocks dopamine entry into vesicles
Amphetamine
stimulates release and blocks reuptake
AT II
located on presynaptic membrane, increases release of NE at synapse
Bretylium, guanethidine
inhibits release of NE on presynaptic membrane
Clinical use of Bethanechol
postoperative ileus, neurogenic ileus, and urinary retention
Action of Bethanechol
Activates Bowel and Bladder smooth muscle; resistant to AChE. Bethany, call (bethanechol), me maybe, if you want to activate your bowels and bladder
Carbachol clinical use
Glaucoma, pupillary constriction, and relief of intraocular pressure.
Pilocarpine clinical use
Potent stimulator of sweat, tears, and saliva; open-angle and closed angle glaucoma
Pilocarpine mech
contracts ciliary muscle of eye (open-angle glaucoma), pupillary sphincter (closed angle glacoma); resistant to AChE. “ you cry, drool, and sweat on your PILOow”
Neostigmine use
postoperative an neurogenic ileus and urinary retention, myasthenia gravis, reversal of neuromuscular junction blockade (postoperative)
PyRIDdostigmine use
myasthenia gravis (long acting) ‘gets rid of myasthenia gravis’
Phystostigmine use
anticholinergic toxicity
What are he anticholinesterases to treat Alzheimer disease?
Donepezil, Rivastigmine, Galantamine
What to use for Dx of myasthenia gravis? why?
Edrophonium. short acting; myasthenia gravis now diagnosed with antibody-AChR Ab test
With all cholinomimetic agents, what should you watch out for?
Exacerbaions of COPD,Athsma, Peptic ulcers
Give an example of an oranophosphate
Parathion; Organophosphates common in insecticides; posoning usually seen in farmers.
What is the antidote for organophosphate posioning (irreversibel acetylchoinesterase inhibitor)?
Atropine (antimuscarinic) + Pralidoxime (regenerates AChE if given early)
Muscarinic antagonists: Atropine, Homatropine, Tropicamide
produces mydriasis and cycloplegia
Muscarinic antagonists: Benztropine
PARKinson disease: ‘PARK my BENZ’
Muscarinic antagonists: Scopolamine
Motion Sickness
Muscarinic antagonists:Ipratropium, Tiotropium
Respiratory: COPD, Athsma
Muscarinic antagonists:Oxybutynin, darifenacin, solifenacin
Genitouinary. Reduce urgency in mild cystitis and reduce bladder spasms. Other agents: tolterodine, fesoterodine, trospium
Muscarinic antagonists: Glycopyrrolate
Gastrointestinal, respiratory: Parentaral: preoperative use to reduce airway secretions. Oral: drooling, peptic ulcer.
Atropine
used to treat bradycardia and for ophthalmic applications
Atropine
can cause acute angle closure in elderly (due to mydriasis), urinary retention in men with prostatic hypertension, and hyperthermia in infants
Jimson weeed (Datura)
gardeners pupil (mydriasis due to plant alkaloids)
Epinepherine
beta > alpha
Norepinephrine
a1 > a2> beta
Isoproterenol receptor/use:
beta1=beta2; electrophysiologic evaluation of tachyarrhythmias. can worsen ischemia
Dopamine
D1=D2>beta>alpha; Use: ustable bradycardia, HF, shock; inotropic and chronotpic alpha effects predominate at high doses.
Dobutamine
beta1 > beta2 > alpha. Use: Heart failure (inotropic>chronotropic), cardiac stress testing
Phenylepherine
alpha1 > alpha 2. Use: hypotension (vasoconstrictor), ocular procedures (mydriatic), rhinitis ( decongestant)
Albuterol, salmeterol, terbutaline
beta2 > beta1. terbutaline to reduce premature uterine contractions
Ephedrine mech and use
indirect general agonist, releases stored catecholamines; Nasal decongestion, urinary incontinence, hypotension
Cocaine mech
indirect general agonist, reuptake inhibitor. Causes vasoconstriction and local anesthesia; never give beta blockers if cocaine intoxication is suspected (leads to unopposed alpha1 activation and extreme hypertension
What are the sympatholytics (alpha 2 agonists)?
Clonidine and alpha methyl-dopa
Clinical use of clonidine
hypertensive urgency (limited situations); does not decrease renal blood flow. ADHD, severe pain, and a variety of off label indications (ethanol and opioid withdrawal).
Clonidine CNS toxicity
CNS depression, bradycardia, hypotension, respiratory depresssion, and small pupil size
alpha-methyldopa clinical use
Hypertension in pregnancy; safe in pregnancy
alpha-methyldopa toxicity
Direct Coombs positive hemolytic anemia, SLE-like syndrome
phenoxybenzamine reversible or irreversible?
irreversible
phentolamine reversible or irreversible?
reversible
phenoxybenzamine use
pheochromocytoma (used preoperatively) to prevent catecholamine hypertensive crisis
phenoxybenzamine toxicity
orthostatic hypotension, reflex tachycardia
phentolamine use
give to patients on MAO inhibitors who eat tyramine containing foods
phenoxybenzamine and phentolamine selective or nonselective?
nonselective
what are the alpha1 selective alpha inhibitors?
prazosin, terazosin, doxazosin, tamsulosin
Use of alpha 1 selective antagonists?
urinary symptoms of BPH; PTSD (prazosin); hypertension (except except tamsulosin)
Toxicity of alpha 1 selective blockers
1st dose orthostatic hypotension, dizziness, headache
alpha 2 selective alpha BLOCKER
mirtazapine
mirtazapine use?
depression
mirtazapine
sedation, increased serum cholesterol, increased appetite
What beta blockers reduce mortality in MI?
metoprolol, cervedilol, and bisoprolol
what beta blockers for a SVT?
metoprolol, esmolol
Timolol
decrease secretion of aqueous humor
toxicity of beta blockers
impotence, CV adverse effects, CNS adverse effects (seizures, sedation, sleep alterations), dyslipidemia, and asthmatics
What beta blocker can cause dyslipidemia?
metoprolol
What are the B1 selective antagonists?
acebutolol (partial agonist) , atenolol, betaxolol, esmolol, metoprolol
what are the nonselective antagonists?
nadolol, pindolol (partial agonist) , propranolol, timolol
what are the nonselevtive alpha beta antagonists?
carvedilol, labetalol
Nebivolol mech
cardiac selective beta adrenergic blockade with stimulation of beta3 receptors which activate nitric oxide synthase in the vasculature
