Anticholinergic drugs, muscarinic drugs and cholinergicestarase drugs

Question 1

Alpha1

Answer 1

Vasoconstriction
• Ejaculation
• Contraction of bladder neck and prostate

Question 2

Alpha2

Answer 2

Locatedinpresynapticjunction • Minimalclinicalsignificance

Question 3

Beta1

Answer 3

Heart
• Increases:
• Heart rate
• Force of contraction
• Velocity of conduction in atrioventricular (AV) node

• Kidney
• Renin release

Question 4

Beta2

Answer 4

Bronchial dilation
• Relaxation of uterine muscle • Vasodilation
• Glycogenolysis

Question 5

Dopamine

Answer 5

Dilates renal blood vessels

Question 6

receptor Specificity of the Adrenergic Neurotransmitters

Answer 6

Epinephrine can activate all alpha and beta receptors but not dopamine receptors
• Norepinephrine can activate alpha1, alpha2, and beta receptors but not beta2 or dopamine receptors
• Dopamine can activate alpha1, beta1, and dopamine receptors

Question 7

Cholinesterase inhibitors

Answer 7

Indirectly prevent the breakdown of aacetylcholine

Question 8

Muscarinic agonists

Answer 8

Bethanechol
• Other muscarinic agonists
• Toxicology of muscarinic agonists

Question 9

• Muscarinic antagonists (anticholinergic drugs)

Answer 9

• Atropine
• Anticholinergic drugs for overactive bladder(urgeincontinence)
• Other muscarinic antagonists
• Toxicology of muscarinic antagonists

Question 10

• Bethanechol

Answer 10

Parasympathomimetic agent”

• Selective agonist at muscarinic cholinergic receptors
• Heart: Bradycardia
• Smooth muscle:
• Lung: Constriction of the bronchi
• Gastrointestinal system: Increased tone and motility
• Bladder: Contraction of detrusor muscle and relaxation of the trigone and sphincter
• Exocrine glands: Increased sweating, salivation, bronchial secretions, and secretion of gastric acid
• Eye: Miosis and contraction of the ciliary muscle

Therapeuticuses:Urinaryretentionandinvestigational gastrointestinal uses
• Adverseeffects:
• Cardiovascular system: Hypotension
• Gastrointestinal system: Increased tone and motility • Exacerbationofasthma
• Dysrhythmias in patients with hyperthyroidism

Question 11

Other muscarinic agonists

Answer 11

• Cevimeline: Derivative of acetylcholine
• Pilocarpine:Used mainly for topical t herapy of glaucoma
• Acetylcholine:Usedforrapidmiosis(pupilconstriction) after delivery in cataract surgery

Question 12

• Toxicology of muscarinic agonists

Answer 12

• Symptoms:Profusesalivation,lacrimation(tearing),visual disturbances, bronchospasm, diarrhea, bradycardia, and hypotension with possible cardiovascular collapse
• Treatment:Atropineandsupportivetherapy

Question 13

Muscarinic Antagonists

Answer 13

• Certain drugs (antihistamines, tricyclic antidepressants, phenothiazine antipsychotics) have prominent antimuscarinic actions
• Use these with caution—or not at all—for patients receiving other muscarinic antagonists

Question 14

Atropine

Answer 14

• Best-known muscarinic antagonist

Pharmacologic effects (receptor blockade)
• Heart: Increases heart rate
• Exocrine glands: Decreases secretions
• Smoothmuscle:Relaxesthebronchi,decreasesthetoneofthe urinary bladder detrusor, and decreases the tone and motility of the gastrointestinal tract
• Eyes: Mydriasis and cycloplegia
• Central nervous system: Mild excitation to hallucinations and
delirium

 Therapeutic uses
• Preanesthetic medication
• Disordersoftheeye
• Bradycardia
• Intestinal hypertonicity and hypermotility
• Muscarinic agonist poisoning
• Peptic ulcer disease
• Asthma
• Biliary colic

 Adverseeffects
• Xerostomia (dry mouth)
• Blurred vision and photophobia
• Elevationofintraocularpressure
• Urinary retention
• Constipation
• Anhidrosis
• Tachycardia
• Asthma

Druginteractions
• Avoid combining atropine with other drugs capable of causing muscarinic blockade

Question 15

Oxybutynin [Ditropan XL, Oxytrol, Gelnique]

Answer 15

• Anticholinergic agent that acts primarily at M3 muscarinic

receptors

Question 16

• Darifenacin

Answer 16

• GreatestdegreeofM3selectivity
• Can reduce OAB symptoms while having no effect on M1 receptors in the brain or M2 receptors in the heart
• Well tolerated
• Drymouthandconstipation

Question 17

Solifenacin

Answer 17

Not as M3 selective

Adverse effects: Drymouthandblurredvision • QTinterval

Question 18

• Tolterodine

Answer 18

• Nonselective muscarinic antagonist • Feweranticholinergicsideeffects
• QTinterval

Question 19

Tolterodine

Answer 19

Nonselective muscarinic antagonist • Feweranticholinergicsideeffects
• QTinterval

Question 20

• Fesoterodine

Answer 20

• Nonselective muscarinic antagonist • Drymouth

* Constipation

Question 21

• Trospium

Answer 21

• Nonselective muscarinic antagonist • Generallywelltolerated
• Drymouth
• Constipation

Question 22

Scopolamine

Answer 22

• Scopolamine
• Anticholinergicdrugwithactionsmuchlikethoseofatropine
• Therapeutic doses of atropine produce mild central nervous system excitation; therapeutic doses of scopolamine produce sedation
• Scopolamine suppresses emesis and motion sickness, whereas atropine does not
• Principalusesforscopolamine:Motionsickness,production of cycloplegia and mydriasis for ophthalmic procedures, and production of preanesthetic sedation and obstetric amnesia

Question 23

Ipratropium bromide

Answer 23

• Anticholinergic drug
• Usedtotreatasthma,chronicobstructivepulmonary disease (COPD), and rhinitis caused by allergies or the common cold
• Inhalationornasalsprayroutes:Notassociatedwithtypical antimuscarinic side effects (dry mouth, blurred vision, urinary hesitancy, constipation)

Question 24

Dicyclomine

Answer 24

• Indicatedforirritablebowelsyndrome(spasticcolon, mucous colitis) and functional bowel disorders (diarrhea, hypermotility)

Question 25

toxicology of Muscarinic Antagonists

Answer 25

• Symptoms
• Drymouth
• Blurred vision
• Photophobia
• Hyperthermia
• Central nervous system effects
• Hot,dry,andflushedskin
• Treatment
• Physostigmine
• Inhibitor of acetylcholinesterase • Warning
• Differentiate between poisoning and an actual psychotic episode

Question 26

Neostigmine

Answer 26

Cholinesterase Inhibitors

• Pharmacologic effects
• BydecreasingthebreakdownofACh,neostigmineandthe other cholinesterase inhibitors make more ACh available; this can intensify transmission at virtually all junctions where ACh is the transmitter

• Cholinesteraseinhibitorscancausebradycardia,bronchial constriction, urinary urgency, increased glandular secretions, increased tone and motility of gastrointestinal smooth muscle, miosis, and focusing of the lens for near vision

• Neuromusculareffects
• Therapeuticdose:Increasesforceofcontractioninskeletal muscle
• Toxiclevels:Decreaseforceofcontraction
• Central nervous system
• Therapeutic levels: Mild stimulation
• Toxic levels: Depression of the central nervous system
• Therapeutic uses
• Myastheniagravis
• Reversalofnondepolarizingneuromuscularblockade
• Used postoperatively
• Treatmentofoverdose
• Likely to elicit substantial muscarinic responses
• May need to administer atropine (muscarinic antagonist)
• Adverseeffects/acutetoxicity
• Excessive muscarinic stimulation
• Neuromuscular blockade
• Treatment with antagonist [Atropine]
• Precautionsandcontraindications
• Obstructionofgastrointestinalorurinarytract
• Peptic ulcer disease
• Asthma
• Coronaryinsufficiency
• Hyperthyroidism