Pharmacology Flashcards
sympathetic alpha-1 R (Gp-q): fxns
- vascular sm muscle contraction
- pupil dilation
- intestine and bladder sphincter contraction
sympathetic alpha-2 R (Gp-i): fxns
- decreases sympathetic outflow
- decreases insulin release and lipolysis
- incr plt aggregation
- decr aqueous humor production (eye)
sympathetic beta-1 R (Gp-s): fxns
- incr HR
- incr heart contractility (inotropy)
- incr renin release (to incr BP via incr ADH, thirst, and vasoconstriction)
- incr lipolysis
sympathetic beta-2 R (Gp-s): fxns
- vasodilation
- bronchodilation
- incr insulin release and lipolysis
- decr uterine tone (tocolysis)
- ciliary muscle relaxation (opp of accommodation), incr aqueous humor production
parasympathetic M1 R (Gp-q): fxns
Works on CNS and enteric nervous system
parasympathetic M2 R (Gp-i): fxns
- Decreases HR
- Decr atrial contractility
parasympathetic M3 R (Gp-q): fxns
- incr exocrine gland secretions (lacrimal, salivary, gastric acid)
- incr gut peristalsis
- incr bladder contraction
- bronchoconstriction
- pupil constriction
- ciliary muscle contraction (Accommodation)
Dopamine D1 R (Gp-s): fxns
- relaxes renal vascular smooth muscle
Dopamine D2 R (Gp-i): fxns
- modulates NT release
Histamine H1 R (Gp-q): fxns
- incr nasal and bronchial mucus production
- incr vascular permeability
- bronchiole contraction
- pruritis
- pain
Histamine H2 R (Gp-s): fxns
- incr gastric acid secretions
Vasopressin V1 R (Gp-q): fxns
- contracts vascular smooth muscle
Vasopressin V2 R (Gp-s): fxns
- incr H2O permeability and reabsorption in collecting tubules
- V”2” for H”2”O reabsorption in collecting “TU”bule
Gq pathway (for H1, Alpha1, V1, M1, M3 = HAVe 1 M&M)
R –Gq-> PLC –> breaks lipids into DAG (-> PK3) and IP3 -> increase Ca2+ –> incr smooth muscle contraction
Gs and Gi pathway
R –Gs/i-> Adenylyl cyclase –> turns ATP to cAMP –> PKA –> incr Ca in heart –> incr heart contractility
MOA of botulinum
blocks ACh release from presynaptic cholinergic neuron at NMJ
MOA of physostigmine, rivastigmine, galantamine, donepezil, edrophonium, neostigmine (and caffeine!)
AchEI
MOA and use of: Bethanechol
Cholinomimetic (Ach)
- activates bowel, bladder: for post-op or neurogenic ileus, urinary retention
MOA and use of: Carbachol
Ach copy
- constricts pupil, relieves intraocular P: for glaucoma
MOA and use of: Methacholine
Stimulates Musc Ach Rs in airway (constricts)
- challenge test for asthma dx
MOA and use of: pilocarpine
Contracts ciliary muscle of eye (for open-angle glaucoma), pupillary sphincter (for closed-angle glaucoma)
- potent stimulatory of sweat, tears, saliva (“cry, sweat, and drool on your PILOow”)
Use of donepezil/galantamine/rivastigmine
incr Ach for Alzeheimer Disease
Use of edrophonium
Old dx for MG (now test for Anti-AChR Ab)
Use of neostigmine
No CNS penetration, so use for postop/neurogenic ileus and urinary retention, postop reversal of NMJ blockade, and MG tx
Use of Physostigmine
Crosses BBB, used to “phy”x atropine OD: incr Ach for anticholinergic toxicity antidote
Use of Pyridostigmine
Incr Ach and muscle strength, long acting MG tx (no CNS penetration)
“pyRIDostiGMine gets RID of MG”
S/E of cholinomimetic drugs
Exacerbation of COPD, asthma, peptic ulcers
Cholinergic toxicity
2/2 AchEi toxicity or organophosphates (irreversibly inhibit AChE): DUMBBELSS Diarrhea Urination Miosis (big pupils) Bronchospasm Bradycardia Excitation of muscle and CNS Lacrimation Sweating Salivation
cholinergic toxicity antidote (2)
atropine (competitively inhibits)
pralidoxime (regenerates AChE if given early)
MOA and use of: Atropine
MOA: muscarinic Ach antagonist
- dilate pupil, and antidote for cholinergic toxicity
MOA and use of: Benztropine
MOA: musc Ach antagonist (CNS)
-for PD-acute dystonia (“park my Benz”)
MOA and use of: Glycopyrrolate
MOA: musc Ach antagonist (GI, resp)
- oral: for drooling, peptic ulcer
- parenteral: preop to reduce airway secretions
MOA and use of: Ipratropium, tiotropium
MOA: musc Ach antag (resp)
- for COPD, asthma
“I PRAy I can breathe soon”
MOA and use of: Oxybutynin, tolteridone
MOA: Musc Ach antagonist (GU)
- reduce bladder spasms and urge incontinence
MOA and use of: Scopolamine
Musc Ach antagonist (CNS)
- for motion sickness
Anticholinergic toxicity
2/2 Atropine, Jimson weed (Datura)
“Can’t pee, can’t see, can’t spit, can’t shit”
- hyperthermia, tachycardia, dry mouth, dry/flushed skin, no sweating, mydriasis (big pupils), constipation, AMS
R action and use of: Albuterol, Salmeterol
Sympathomimetic: B2 > B1
- Albuterol: acute asthma
- Salmeterol: chronic asthma or COPD control
R action and use of: Dobutamine
Sympathomimetic: B1 > B2, a
- for HF (inotropic > chronotropic), cardiac stress testing
R action and use of: Dopamine
Sympathomimetic: D1 = D2 > B > a
- for unstable bradycardia, HF, shock
- inotropic and chronotropic (alpha effects) at high doses
R action and use of: Epi
Sympathomimetic: Beta > alpha
- for anaphylaxis, asthma, open-angle glaucoma
- alpha effects at high doses
- B2 effects much stronger than NE
- alpha blockage causes BP depression b/c of B2 action (vs phenylephrine which is only effect-suppressed)
R action and use of: Isoproterenol
Sympathomimetic: B1=B2
- EP eval of tachyarrhythmias
R action and use of: NE
Sympathomimetic: a1 > a2 > B1
- for hypotension (but will decr renal perfusion)
R action and use of: Phenylephrine
Sympatomimetic: a1 > a2
- vasoconstriction (for hypotension)
- dilates pupils for eye procedures
- decongestant
- not as susceptible to alpha blockage as Epi (get suppression of pressor effect, but no net BP depression b/c has no B2 action)
action of alpha-1 adrenergic receptors (NE > Epi)
- smooth muscle contraction
- pupil dilation (mydriasis)
- skin, mucosa and GI/GU vasoconstriction/sphincter constriction
action of alpha-2 adrenergic receptors (Epi > NE)
- smooth muscle mixed effects
- platelet activation
action of beta-1 adrenergic receptors (Epi=NE)
+ chronotropy
+ incr intropy
+ incr amylase secretion
action of beta-2 adrenergic receptors (Epi)
smooth muscle relaxation (ex bronchodilation)
MOA and use of: amphetamine
indirect sympathetic general agonist, reuptake inhibitor, releases stored catecholamines
- for: narcolepsy, obesity, ADHD
MOA and effects of: cocaine
indirect sympathetic general agonist and reuptake inhibitor
- causes: vasoconstriction and local anesthesia
- don’t give BB w/cocaine CP b/c can cause unopposed alpha1 action -> extreme HTN
MOA and use of: ephedrine
indirect sympathetic general agonist, releases stored catecholamines
- for: nasal decongestant, urinary incontinence, hypotension
NE effect on BP and HR
NE increases SBP and DBP (from alpha1 vasoconstriction) –> incr MAP –> reflex bradycardia
Isoproterenol effect on BP and HR
Isoproterenol causes B2 vasodilation –> decr MAP –> incr HR via B1 and reflex activity
MOA and use of: Clonidine
a2 agonist (sympatholytic) - for HTN urgency, ADHD, Tourette syndrome
sympatholytic toxicity
Clonidine: CNS depression, bradycardia, hypotension, resp depression, miosis
alpha-methyldopa: direct coombs+ hemolysis, SLE_like syndrome
MOA and use of: Phenoxybenzamine
MOA: irreversible nonselective alpha blocker
- for pheos (to prevent catecholamine-HTN crisis)
MOA and use of: Phentolamine
MOA: reversible nonselective alpha blocker
- for pts on MAOIs who eat tyrosine foods
alpha blocker S/Es (2)
orthostatic hypotension (w/a1 specific, only w/1st dose) reflex tachycardia
MOA and use of: Prazosin, Terazosin, Doxazosin, Tamsulosin (and S/E’s)
MOA: alpha1-selective blockers (-osin endings)
- for BPH, PTSD (prazosin), HTN (except tamsulosin)
S/E: can get HA and orthostasis (1st use), dizziness
MOA and use of: Mirtazepine (and S/E’s)
MOA: alpha2-selective blocker
- for: depression
- S/E: sedation, incr appetite/wt gain (and incr chol)
MOA of Bb effects on: angina
decr heart rate and contractility –> decr O2 consumption
Bb effects on: MI (metoprolol, carvedilol, bisoprolol) and chronic HF
decrease mortality
MOA of Bb effects on: SVT (metop, esmolol)
decr AV conduction velocity (class II antiarrhythmic)
MOA of Bb effects on: HTN
decr CO, decr renin secretion (due to B1-blockade on JGA cells)
MOA of Bb effects on glaucoma (timolol)
decr secretion of aqueous humor
Bb toxicity
impotence, bradycardia, AV block, Sz, sedtion, asthma/COPD exacerbation
B1 selective blockers (B1 > B2): in 1st half of alphabet (A to M)
acebutolol (partial ag), atenolol, betaxolol, esmolol metoprolol
Nonselective Bbs (B1=B2): in 2nd half (N to Z)
nadolol, pindolol (partial ag), propranalol, timolol
nonselective alpha and beta antagonists (modified “olol” to -ilol or -alol)
carvedilol, labetalol
Antidote to acetaminophen toxicity
N-acetylcysteine (NAC) - replenishes glutathione
