Pharmacology - Adrenergic Antagonists and Cholinergic Agonists (Exam 2) Flashcards
Which system do adrenergic antagonists inhibit?
SNS (fight or flight)
Most adrenergic antagonists are _________ antagonists for ____ or ____ receptors
competitive; a or B
Some adrenergic antagonists are _______ acting ____ receptor agonists
centrally; a2
What are adrenergic antagonists used to treat?
Cardiovascular and non-cardiovascular diseases
What do a1 antagonists (blockers) INHIBIT?
Vasoconstriction
Bladder sphincter contraction
Which drug is an a1 selective antagonist/blocker?
Prazosin (and other -osins)
What does Prazosin (a1 selective antagonist) block?
a1 receptors in vascular smooth muscles
What is the pharmacological effect of Prazosin (a1 selective antagonist)?
Vasodilation (decreases BP)
Prazosin (a1 selective antagonist) is used for the treatment of what?
Hypertension
Congestive heart failure
Benign prostate hyperplasia
What kind of drug is Tamsulosin (Flomax)?
a1 selective antagonist/blocker
What does Tamsulosin (Flomax) (a1 selective antagonist/blocker) have an effect on?
Prostate - helps older men urinate
(little effect on BP)
What are the adverse effects of a1 blockers?
Orthostatic and postural hypotension
Floppy iris syndrome during cataract surgery
(a1 agonist is given to dilate the pupil for surgery, but pt taking a1 blocker will have interaction that causes iris to be confused and “floppy”)
Which drugs are non-selective a blockers?
Phentolamine
Phenoxybenzamine
What do Phentolamine
and Phenoxybenzamine (non-selective a blockers) treat?
Epinephrine secreting tumors of adrenal gland
What drugs are B blockers?
-lol drugs
What are B blockers used to treat?
Cardiovascular effects due to B1 blockage
What are the cardiovascular effects of B blockers?
Decreased HR (anti-arrhythmic)
Decreased force of contraction
Decreased BP
What are the physiological effects of B blockers?
Decreased BP, O2 demand, and cardiac workload
What are the adverse effects of B blockers?
Bronchoconstriction
Vasoconstriction
(since B blockers are non-selective, they can affect B2 receptors as well)
Which drug is a 1st generation B blocker?
Propranolol
Is Propranolol (B blocker) selective or non-selective?
Non-selective
What are the side effects of Propranolol (B blocker)?
Bronchoconstriction
Vasoconstriction
(blocks B2 receptors since it is non-selective)
What is a potential outcome of using lidocaine with epinephrine on patients taking Propranolol (B blocker)?
Cardiac arrest
(Patients taking Propranolol have blockage of B2 receptors which inhibits vasodilation. Too much epinephrine causes enhanced vasoconstriction in these patients)
Epinephrine works on which receptors?
a1 (vasoconstriction)
B2 (vasodilation)
What is a potential outcome of using Propranolol (B blocker) on patients with asthma or COPD?
Increased bronchoconstriction
(since B2 receptors in lungs are blocked, thus blocking bronchodilation)
What drug is a 2nd generation B blocker?
Metoprolol
Is Metoprolol (B blocker) selective or non-selective
B1 selective
Which drugs are a 3rd generation B blocker?
Labetalol
Carvedilol
Are Labetalol and Carvedilol (B blockers) selective or non-selective?
Non-selective
What other receptor do Labetalol and Carvedilol (B blockers) block?
a1
(but effect on B is > than a1)
What are the physiological effects of Labetalol and Carvedilol (B blockers)?
Decrease BP, HR, cardiac workload (blocks B1)
Vasodilation (blocks a1)
Which B blockers are 1st line drugs?
Labetalol and Carvedilol
What is Carvedilol (B blocker) used to treat?
Hypertension
Heart failure
What specific cardiovascular diseases are B blockers generally used for?
Arrhythmia
Heart failure
Angina
Hypertension
Which drugs are a/B mixed antagonists (B non-specific, a1)
Labetalol
Carvedilol
What are the adverse reactions of B blockers?
Bradycardia
Fatigue
What happens to patients who chronically use B blockers?
B receptor becomes supersensitive
(slow withdrawal of the drug is required)
What do B blockers not mix with?
Ca2+ channel blockers
What are the metabolic effects of B blockers?
Activation of B2 in liver (increases plasma glucose)
Inhibition of B2 (hypoglycemia in type II diabetes)
Muscarinic agonists activate _______ subtypes of the receptor (M1-M5)
most (if not all!)
(this explains their variety of pharmacological actions)
What are cholinergic drug receptors?
Muscarinic and nicotinic
What are muscarinic and nicotinic receptors stimulated by?
ACh
Which physiological systems do central cholinergic systems regulate and influence?
Regulate cardiovascular, respiratory, GI, etc
Influence cognition and emotion
Do cholinergic drugs produce effects on the CNS?
Depends on the lipophilicity of the drug
Cholinergic/muscarinic agonists have ________ actions and have effects on _______ _______ (sympathetic)
parasympathomimetic; sweat glands
Cholinergic agonists affect which system?
Both parasympathetic and sympathetic
(there are cholinergic receptors for ACh in both)
What do cholinergic agonists affect in the parasympathetic system?
Heart
Lungs
GI
What do cholinergic agonists affect in the sympathetic system?
Sweat glands
Muscarinic (parasympathomimetic) drugs have _________ parasympathetic responses
increased
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the heart?
Decreased HR, BP, contractility, AV conduction, cardiac output
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the lungs?
Bronchoconstriction
(bad for asthma/COPD patients)
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the eyes?
Miosis, decreased intraocular pressure
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the blood vessels?
Vasodilation
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the GI system?
Excite smooth muscle
Increased GI activity, motility, secretion
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the bladder?
Contract detrusor muscle
Relax sphincter muscle
Increased urination
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the exocrine glands?
Increased lacrimation, GI secretions, sweating, salivation
What pharmacologic effects do Muscarinic (parasympathomimetic) drugs have on the brain?
Inhibit ACh-esterase, leading to increased ACh
Does every muscarinic drug produce all the physiological effects?
NO
Peripheral nicotinic effects are ________, since they are selective towards _________ receptors
minimal; muscarinic
T/F direct acting cholinergic agonists are clinically useful
FALSE, they are not clinically useful due to short duration of action
What are the analogs of ACh?
Bethanechol
Methacholine
What is the naturally occurring alkaloid?
Pilocarpine (treats xerostomia)
Analogs of ACh and naturally occurring alkaloids produce prominent _________ effects
muscarinic (aka parasympathomimetic)
What are indirect acting cholinergic agonists called?
Anti-cholinesterases
(ACh esterase inhibitors)
T/F both direct acting cholinergic agonists and anti-cholinesterases produce cholinergic effects
True
What drug is an anti-cholinesterase?
Neostigmine
Physostigmine
What are the 2 subclasses of anti-cholinesterases?
- Reversible inhibitors (neostigmine, physostigmine)
- Irreversible inhibitors (organophosphates - pesticides and nerve gas)
What is the derivative of physostigmine (reversible anti-cholinesterase)?
Neostigmine
Anti-cholinesterases require _______ to be present
ACh
Anti-cholinesterases have pharmacological actions identical to those of ACh, producing _______ and _______ effects
Muscarinic and nicotinic
What is Myasthenia Gravis?
Chronic autoimmune disease
Myasthenia Gravis has auto-antibodies against ____ ________ receptors
ACh nicotinic
What is used to treat Myasthenia Gravis by increasing ACh and thus neuromuscular transmission via nicotinic receptors?
Reversible anti-cholinesterase inhibitors (neostigmine)
What neurochemical is affected early in the course of Alzheimer’s?
ACh
What is used to treat Glaucoma?
Pilocarpine
What is used to treat paralytic ileus and bladder atony (after abdominal/pelvic surgery)?
Bethanechol
Neostigmine
What are the adverse effects of cholinergic drugs?
Colon “choline” SLUDGE
Salivation, sweating
Lacrimation
Urination
Defecation
GI distress
Emesis
Do not take _______ drugs with GI or urinary tract obstruction
cholinergic
