Cholinergic Drugs: Agonists, Antagonists, and Inhibitors

What is the primary action of bethanechol on the heart?

Slowing it down

Why is bethanechol described as a quaternary ammonium compound?

Because it has a positive charge

In which system does bethanechol increase tone and motility?

Gastrointestinal system

What is the primary effect of bethanechol on the smooth muscle in the lung?

Constriction of bronchi Signup and view all the answers

What is the onset of action for bethanechol when administered orally?

30-60 minutes Signup and view all the answers

What is the duration of action for bethanechol?

~1 hour Signup and view all the answers

Why are cholinergic drugs not recommended in the elderly population?

They can worsen existing health conditions in the elderly Signup and view all the answers

What is the role of cholinesterase inhibitors in preventing acetylcholine breakdown?

They prevent acetylcholine breakdown Signup and view all the answers

What is the primary effect of muscarinic antagonists?

Blocking acetylcholine effects Signup and view all the answers

Why should cholinergic drugs be used with caution in pregnant females?

They can affect fetal development Signup and view all the answers

Why should cholinergic drugs not be used in lactating females?

They decrease milk production due to anticholinergic side effects Signup and view all the answers

Which of the following is a therapeutic use of bethanechol?

Treatment of urinary retention Signup and view all the answers

What are the adverse effects of bethanechol?

Hypotension, abdominal cramps, and diarrhea Signup and view all the answers

What are the symptoms of muscarinic poisoning?

Profuse salivation, visual disturbances, and bradycardia Signup and view all the answers

What is the main therapeutic use of pilocarpine?

Treatment of glaucoma Signup and view all the answers

What are the alternative names for muscarinic antagonists?

Parasympatholytic drugs and anticholinergic drugs Signup and view all the answers

What is the mnemonic used to remember the side effects of muscarinic poisoning?

SLUDGE Signup and view all the answers

Why do certain drugs like anti-histamines need to be used with caution in patients receiving muscarinic antagonists?

They may exacerbate the adverse effects of muscarinic antagonists Signup and view all the answers

What is the primary effect of cevimeline?

Treatment of dry mouth in Sjogren's syndrome Signup and view all the answers

Acetylcholine is used for rapid miosis after delivery in which procedure?

Cataract surgery Signup and view all the answers

What is the effect of direct-acting muscarinic agonists on cholinesterase inhibitors?

They potentiate the effects of cholinesterase inhibitors Signup and view all the answers

Why is pilocarpine an exception among muscarinic agonists?

It can cross cell membranes easily. Signup and view all the answers

What effect does atropine have on muscarinic receptors?

It desensitizes them. Signup and view all the answers

Why should bethanechol be used with caution in lactating females?

It decreases milk production due to anticholinergic side effects Signup and view all the answers

What is the primary effect of atropine on muscarinic receptors?

Inhibition Signup and view all the answers

How does bethanechol affect the heart?

It slows it down Signup and view all the answers

What is the primary therapeutic use of muscarinic antagonists?

Dilating the bronchi in the lung Signup and view all the answers

What is the duration of action for bethanechol when administered orally?

30-60 minutes Signup and view all the answers

Why are cholinergic drugs not recommended for the elderly population?

They affect receptors causing unwanted side effects Signup and view all the answers

What is the main effect of bethanechol on smooth muscle in the lung?

Constriction of bronchi Signup and view all the answers

What is the primary therapeutic use of bethanechol?

Treating urinary retention Signup and view all the answers

What is the adverse effect of bethanechol that can result in exacerbation of asthma?

Increased motility of GI tract Signup and view all the answers

Which structure is mentioned as an exception among muscarinic agonists due to its ability to cross membranes easily?

Pilocarpine Signup and view all the answers

What is the mnemonic used to remember the side effects of muscarinic poisoning?

SLUDGE Signup and view all the answers

What are the symptoms of muscarinic poisoning?

Visual disturbances, bronchospasm, and hypotension Signup and view all the answers

What is the role of cholinesterase inhibitors in muscarinic poisoning?

Exacerbating muscarinic symptoms Signup and view all the answers

Why should certain drugs like anti-histamines be used with caution in patients receiving muscarinic antagonists?

They may have prominent anti-muscarinic actions Signup and view all the answers

What is the primary effect of cevimeline?

Treating dry mouth in Sjogren's syndrome Signup and view all the answers

What are the pharmacologic effects of muscarinic receptor blockade caused by atropine?

Increases heart rate, decreases secretions in exocrine glands, relaxes smooth muscle in the bronchi, and decreases the tone of the urinary bladder detrusor Signup and view all the answers

Which adverse effect is NOT associated with atropine use?

Sedation Signup and view all the answers

In which conditions can atropine be used therapeutically?

Asthma and peptic ulcer disease Signup and view all the answers

What is the primary use of AtroPen?

Cholinesterase inhibitor poisoning Signup and view all the answers

What is the alternative term for overactive bladder?

Detrusor instability Signup and view all the answers

Which symptom is NOT associated with overactive bladder?

Dysuria Signup and view all the answers

What is the primary effect of atropine on the eyes?

Mydriasis Signup and view all the answers

What is the route of administration for Atropine drops used in ophthalmology?

Topical Signup and view all the answers

What effect does atropine have on the tone and motility of the GI tract?

Decreases tone and motility Signup and view all the answers

What is an example of a therapeutic use of atropine?

Biliary colic Signup and view all the answers

What adverse effect can result from atropine use?

Elevation of interocular pressure Signup and view all the answers

Which formulation of oxybutynin provides the longest duration of action?

Transdermal patch Signup and view all the answers

What is the main reason for the high incidence of dry mouth associated with oxybutynin use?

Blockade by oxybutynin itself Signup and view all the answers

What is the unique feature of darifenacin that makes it well-tolerated?

M3 selectivity Signup and view all the answers

Which drug interaction can alter oxybutynin blood levels?

Inhibition of CYP3A4 Signup and view all the answers

What is a prominent side effect of darifenacin and oxybutynin in the pediatric and geriatric populations?

Hallucinations and agitation Signup and view all the answers

Which side effect is NOT associated with oxybutynin use?

Constipation Signup and view all the answers

What is the most common side effect associated with darifenacin use?

Dry mouth Signup and view all the answers

Which condition can be exacerbated by the side effects of oxybutynin and darifenacin?

Asthma Signup and view all the answers

What can intensify the anticholinergic side effects when used in combination with oxybutynin?

SSRIs Signup and view all the answers

What is the primary effect of darifenacin on muscarinic receptors?

M3 selectivity Signup and view all the answers

Which muscarinic antagonist is a CYP2D6 and CYP3A4 substrate?

Fesoterodine Signup and view all the answers

What is the mechanism of action of Mirabegron?

Activates adenylyl cyclase and forms cyclic adenosine monophosphate Signup and view all the answers

Which muscarinic antagonist is a moderate inhibitor of CYP2D6 and a minor inhibitor of CYP3A4?

Solifenacin Signup and view all the answers

Which muscarinic antagonist can cause QT prolongation and an increase in blood pressure?

Mirabegron Signup and view all the answers

What is the main adverse effect associated with Trospium?

Constipation Signup and view all the answers

What distinguishes Mirabegron from other drug classes in terms of producing a therapeutic effect?

It activates beta-3-adrenoreceptors by norepinephrine. Signup and view all the answers

Which drugs have been evaluated as non-traditional therapies for overactive bladder?

Venlafaxine and duloxetine Signup and view all the answers

What is the primary role of scopolamine?

Production of cycloplegia Signup and view all the answers

Ipratropium bromide is used to treat which conditions?

Asthma, COPD, and rhinitis caused by allergies or the common cold. Signup and view all the answers

What are the therapeutic uses of mydriatic-cycloplegics?

To produce mydriasis and cycloplegia for ophthalmic procedures. Signup and view all the answers

What is the specific antidote to poisoning by the irreversible cholinesterase inhibitors?

Pralidoxime Signup and view all the answers

What autoimmune process characterizes myasthenia gravis?

Antibodies attack the nicotinic m receptors on the skeletal muscle Signup and view all the answers

Which drug does not cross the blood-brain barrier and will not reduce CNS effects?

Atropine Signup and view all the answers

What is the primary effect of neostigmine during myasthenic crisis?

Cholinesterase inhibition Signup and view all the answers

What is the distinguishing factor between a cholinergic crisis and a myasthenic crisis when challenged with edrophonium?

Increased muscle strength Signup and view all the answers

What is the initial treatment for a cholinergic crisis?

Atropine Signup and view all the answers

What is the role of benzodiazepine in a cholinergic crisis?

Suppresses convulsions Signup and view all the answers

What can atropine be used for if muscarinic responses become excessive due to cholinesterase inhibitors?

Suppress them Signup and view all the answers

What differentiates neostigmine and atropine in terms of their specific effects?

Atropine reduces muscarinic stimulation, while neostigmine reverses inhibition of cholinesterase. Signup and view all the answers

What is the effect of pralidoxime in cholinergic crisis?

Dissociating inhibitors from the active center of cholinesterase Signup and view all the answers

What is the specific antidote to poisoning by irreversible cholinesterase inhibitors?

Physostigmine Signup and view all the answers

Which drug does not readily cross membranes, has minimal effects on the brain and fetus, and is a poor substrate for cholinesterase?

Pyridostigmine Signup and view all the answers

What is the primary clinical application of irreversible cholinesterase inhibitors?

Glaucoma Signup and view all the answers

Which drug is viewed as an indirect acting cholinergic agonist, lacks muscarinic ganglionic and neuromuscular selectivity, and has limited therapeutic applications?

Pyridostigmine Signup and view all the answers

What are the symptoms of muscarinic poisoning?

Dry mouth, blurred vision, photophobia, and hot, dry flush skin Signup and view all the answers

What is the role of atropine in the treatment of muscarine antagonist poisoning?

Blocks muscarinic receptors Signup and view all the answers

What is the main adverse effect associated with trospium?

QT prolongation Signup and view all the answers

Which structure among muscarinic antagonists can cause QT prolongation and an increase in blood pressure?

Scopolamine Signup and view all the answers

What effect does atropine have on the eyes?

Causes dilation of the pupils Signup and view all the answers

What is the primary effect of atropine on the ciliary muscle in the eyes?

Relaxes the ciliary muscle Signup and view all the answers

Which of the following best describes the effect of atropine on the accommodation reflex in the eyes?

Inhibits the accommodation reflex Signup and view all the answers

Which side effect is NOT commonly associated with oxybutynin use?

Hypertension Signup and view all the answers

What can intensify the anticholinergic effects of oxybutynin when used in combination?

Antihistamines Signup and view all the answers

Which population is more likely to experience hallucinations and agitation as side effects of oxybutynin?

Elderly Signup and view all the answers

What is the primary difference in the metabolism of noncatecholamines compared to catecholamines?

Noncatecholamines are not substrates for COMT and metabolize slowly by MAO. Signup and view all the answers

What is the therapeutic effect of activating alpha-1 receptors?

Vasoconstriction in blood vessels of the skin, viscera, and mucous membranes Signup and view all the answers

What is the primary use of B2 receptor agonists?

Treatment of asthma Signup and view all the answers

Which receptor activation is associated with the risk of angina in patients with compromised coronary circulation?

Beta-1 receptors Signup and view all the answers

What effect does activation of B2 receptors have on the uterus?

Relaxation of uterine smooth muscle Signup and view all the answers

Which receptor subtype does epinephrine act on?

A1, A2, B1, B2 Signup and view all the answers

What is a potential adverse effect of B1 receptor activation?

Tachycardia Signup and view all the answers

Isoproterenol is less selective than albuterol because it acts at which receptors?

B1 and B2 Signup and view all the answers

What is the effect of activating alpha-2 receptors in the central nervous system?

Inhibition of NE release Signup and view all the answers

What is a potential adverse effect of oxybutynin due to its action on muscarinic receptors?

Hyperglycemia Signup and view all the answers

Activation of Dopamine receptors can improve perfusion to which organ?

Kidneys Signup and view all the answers

Which group of adrenergic agonists cannot be used orally, has a brief duration of action, and cannot cross the blood-brain barrier?

Catecholamines Signup and view all the answers

What is the primary mechanism by which indirect adrenergic agonists work?

Promotion of norepinephrine release Signup and view all the answers

Which enzyme is responsible for the quick metabolism of catecholamines?

Monoamine oxidase [MAO] Signup and view all the answers

Which adrenergic agonist is known for its inability to be used orally, short duration of action, and inability to cross the blood-brain barrier?

Norepinephrine Signup and view all the answers

Which major class of adrenergic agonists includes dopamine, epinephrine, isoproterenol, and ephedrine?

Catecholamines Signup and view all the answers

What distinguishes catecholamines from noncatecholamines in terms of their availability for oral use and duration of action?

Availability for oral use and duration of action Signup and view all the answers