Pharm (Pages 225-248) Flashcards
α1
G-Protein Class/Major Functions
q
Increase vascular smooth muscle contraction, Increase pupillary dilator muscle contraction (mydriasis), Increase intestinal and bladder sphincter muscle contraction
α2
G-Protein Class/Major Functions
i
Decreases sympathetic outflow, Decreases insulin release, Decreases, lipolysis, Decreases platelet aggregation
β1
G-Protein Class/Major Functions
s
Increase heart rate, Increase contractility, Increase renin release, Increase lipolysis
β2
G-Protein Class/Major Functions
s
Vasodilation, bronchodilation, Increase heart rate, Increase contractility, Increase lipolysis, Increase insulin release, DECREASED uterine tone (tocolysis), ciliary muscle relaxation, q aqueous humor production
M1
G-Protein Class/Major Functions
q
CNS, enteric nervous system
M2
G-Protein Class/Major Functions
i
Decreased heart rate and contractility of atria
M3
G-Protein Class/Major Functions
q
Increased exocrine gland secretions (e.g., lacrimal, salivary, gastric acid), increased gut peristalsis, increased bladder contraction, bronchoconstriction, decreased pupillary sphincter muscle contraction (miosis), ciliary muscle contraction (accommodation)
D1
G-Protein Class/Major Functions
s
Relaxes renal vascular smooth muscle
D2
G-Protein Class/Major Functions
i
Modulates transmitter release, especially in brain
H1
G-Protein Class/Major Functions
q
Increases nasal and bronchial mucus production, Increases vascular permeability, contraction of bronchioles, pruritus, and pain
H2
G-Protein Class/Major Functions
s
Increases gastric acid secretion
V1
G-Protein Class/Major Functions
q
Increases vascular smooth muscle contraction
V2
G-Protein Class/Major Functions
s
Increases H2O permeability and reabsorption in the collecting tubules of the kidney (V2 is found in the 2 kidneys)
Bethanechol
Clinical applications/action
Postoperative ileus, neurogenic ileus, and
urinary retention
Activates bowel and bladder smooth
muscle; resistant to AChE. “Bethany, call
(bethanechol) me, maybe, if you want to
activate your bowels and bladder.”
Direct agonist
Carbachol
Clinical applications/action
Glaucoma, pupillary constriction, and relief of
intraocular pressure
Carbon copy of acetylcholine.
Direct agonist
Pilocarpine
Clinical applications/action
Potent stimulator of sweat, tears, and saliva
Open-angle and closed-angle glaucoma
Contracts ciliary muscle of eye (open-angle glaucoma), pupillary sphincter (closed-angle glaucoma); resistant to AChE. “You cry, drool, and sweat on your ‘pilow.’ ”
Direct agonist
Methacholine
Clinical applications/action
Challenge test for diagnosis of asthma
Stimulates muscarinic receptors in airway when inhaled.
Direct agonist
Neostigmine
Clinical applications/action
Postoperative and neurogenic ileus and urinary retention, myasthenia gravis, reversal of neuromuscular junction blockade (postoperative)
Increases endogenous ACh.
Neo CNS = No CNS penetration.
Indirect agonist
Pyridostigmine
Clinical applications/action
Myasthenia gravis (long acting); does not penetrate CNS
Increases endogenous ACh; increases strength. Pyridostigmine gets rid of myasthenia gravis.
Indirect agonist
Physostigmine
Clinical applications/action
Anticholinergic toxicity (crosses blood-brain barrier to CNS)
Increases endogenous ACh. Physostigmine “phyxes”
atropine overdose.
Indirect agonist
Donepezil,
rivastigmine,
galantamine
Clinical applications/action
Alzheimer disease
Increases endogenous ACh.
Indirect agonist
Edrophonium
Clinical applications/action
Diagnosis of MG (extremely short acting)
MG is now diagnosed by anti-AChR Ab test
Increases endogenous ACh.
Indirect agonist
With all cholinomimetic agents, watch for:
With all cholinomimetic agents, watch for exacerbation of COPD, asthma, and peptic ulcers when giving to susceptible patients.
Indirect agonist
Cholinesterase inhibitor poisoning
Antidote:
Often due to organophosphates, such as
parathion, that irreversibly inhibit AChE.
Causes Diarrhea, Urination, Miosis,
Bronchospasm, Bradycardia, Excitation
of skeletal muscle and CNS, Lacrimation,
Sweating, and Salivation.
DUMBBELSS.
Organophosphates are components of
insecticides; poisoning usually seen in farmers.
Antidote—atropine (competitive inhibitor) +
pralidoxime (regenerates AChE if given early).
Atropine,
homatropine,
tropicamide
Clinical organ system/applications
Eye
Produce mydriasis and cycloplegia.
Muscarinic antagonist
Benztropine
Clinical organ system/applications
CNS
Parkinson disease—“Park my Benz.”
Muscarinic antagonist
Scopolamine
Clinical organ system/applications
CNS
Motion sickness.
Muscarinic antagonist
Ipratropium,
tiotropium
Clinical organ system/applications
Respiratory
COPD, asthma (“I pray I can breathe soon!”).
Muscarinic antagonist
Oxybutynin,
darifenacin, and
solifenacin
Clinical organ system/applications
Genitourinary
Reduce urgency in mild cystitis and reduce
bladder spasms. Other agents: tolterodine,
fesoterodine, trospium.
Muscarinic antagonist
Glycopyrrolate
Clinical organ system/applications
Gastrointestinal, respiratory
Parenteral: preoperative use to reduce airway secretions.
Oral: drooling, peptic ulcer.
Muscarinic antagonist
Atropine toxicity
Side effects
Increased body temperature (due to decreased sweating);
rapid pulse; dry mouth; dry, flushed skin; cycloplegia; constipation; disorientation
Can cause acute angle-closure glaucoma in elderly (due to mydriasis), urinary retention in men with prostatic hyperplasia, and hyperthermia in infants
Side effects: Hot as a hare Dry as a bone Red as a beet Blind as a bat Mad as a hatter
Jimson weed (Datura) p gardeners pupil (mydriasis due to plant alkaloids)
Epinephrine
Effect/application
β > α
Anaphylaxis, open angle glaucoma, asthma,
hypotension; α effects predominate at high
doses
Sympathomimetics
Norepinephrine
Effect/application
α1 > α2 > β1
Hypotension (but r renal perfusion)
Sympathomimetics
Isoproterenol
Effect/application
β1 = β2
Electrophysiologic evaluation of tachyarrhythmias. Can worsen ischemia.
Sympathomimetics
Dopamine
Effect/application
D1 = D2 > β > α
Unstable bradycardia, heart failure, shock; inotropic and chronotropic α effects predominate at high doses
Sympathomimetics
Dobutamine
Effect/application
β1 > β2, α
Heart failure (inotropic > chronotropic), cardiac stress testing
Sympathomimetics
Phenylephrine
Effect/application
α1 > α2
Hypotension (vasoconstrictor), ocular procedures (mydriatic), rhinitis (decongestant)
Sympathomimetics
Albuterol, salmeterol,
terbutaline
Effect/application
β2 > β
Albuterol for acute asthma; salmeterol for long-term asthma or COPD control; terbutaline to reduce premature uterine contractions
Sympathomimetics
Amphetamine
Effect/application
Indirect general agonist, reuptake inhibitor, also releases stored catecholamines
Narcolepsy, obesity, attention deficit disorder
Indirect sympathomimetics
Ephedrine
Effect/application
Indirect general agonist, releases stored
catecholamines
Nasal decongestion, urinary incontinence,
hypotension
Indirect sympathomimetics
Cocaine
Effect/application
Indirect general agonist, reuptake inhibitor
Causes vasoconstriction and local anesthesia; never give β-blockers if cocaine intoxication is suspected (can lead to unopposed α1 activation and extreme hypertension)
Indirect sympathomimetics
Clonidine
Application/toxicity
Hypertensive urgency (limited situations); does not decrease renal blood flow ADHD, severe pain, and a variety of off-label indications.
CNS depression, bradycardia, hypotension,
respiratory depression, and small pupil size
Sympatholytics (α2-agonists)
α-methyldopa
Application/toxicity
Hypertension in pregnancy
Safe in pregnancy
Direct Coombs + hemolytic anemia, SLE-like
syndrome
Sympatholytics (α2-agonists)
Phenoxybenzamine
(irreversible)
Application/toxicity
Pheochromocytoma (used preoperatively) to prevent catecholamine (hypertensive) crisis
Orthostatic hypotension, reflex tachycardia
Nonselective α-blockers
Phentolamine
(reversible)
Application
Give to patients on MAO inhibitors who eat
tyramine-containing foods
Nonselective α-blockers
Prazosin, terazosin, doxazosin, tamsulosin
Application/toxicity
α1 selective blockers
Urinary symptoms of BPH; PTSD (prazosin);
hypertension (except tamsulosin)
1st-dose orthostatic hypotension, dizziness,
headache
Mirtazapine
Application/toxicity
α2 selective blockers
Depression
Sedation, increased serum cholesterol, increased appetite
β-blocker toxicity
Impotence, cardiovascular adverse effects (bradycardia, AV block, CHF), CNS adverse effects (seizures, sedation, sleep alterations), dyslipidemia (metoprolol), and asthmatics/COPDers (may cause exacerbation)
Avoid in cocaine users due to risk of unopposed α-adrenergic receptor agonist activityDespite theoretical concern of masking hypoglycemia in diabetics, benefits likely outweigh risks; not contraindicated
β1-selective antagonists
(β1 > β2)—acebutolol (partial agonist), atenolol, betaxolol, esmolol, metoprolol
Selective antagonists mostly go from A to M (β1 with 1st half of alphabet)
β Nonselective antagonists
(β1 = β2)—nadolol, pindolol (partial agonist), propranolol, timolol
Nonselective antagonists mostly go from N to Z (β2 with 2nd half of alphabet)
Nonselective α- and β-antagonists
Nonselective α- and β-antagonists—carvedilol, labetalol
Nonselectives α- and β-antagonists have modified suffixes (instead of “-olol”)
Nebivolol
Nebivolol combines cardiac-selective β1-adrenergic blockade with stimulation of β3-receptors, which activate nitric oxide synthase in the vasculature
Acetaminophen
Antidote/treatment
N-acetylcysteine (replenishes glutathione)
AChE inhibitors, organophosphates
Antidote/treatment
Atropine followed by pralidoxime
Amphetamines (basic)
Antidote/treatment
NH4Cl (acidify urine)
Antimuscarinic, anticholinergic agents
Antidote/treatment
Physostigmine salicylate, control hyperthermia
Benzodiazepines
Antidote/treatment
Flumazenil
β-blockers
Antidote/treatment
Glucagon
Carbon monoxide
Antidote/treatment
100% O2, hyperbaric O2
Copper, arsenic, gold
Antidote/treatment
Penicillamine
Cyanide
Antidote/treatment
Nitrite + thiosulfate, hydroxocobalamin
Digitalis
Antidote/treatment
Anti-dig Fab fragments
