Cholinergic Pharmacology I Flashcards
Symptoms of intoxication of muscarine mimic what branch of the ANS?
PNS
What was the first identified agonist of muscarinic receptors?
Muscarine (compound found in certain mushrooms)
SLUD refers to the rapid classic spectrum of generalized muscarinic receptor activation. What does SLUD stand for?
Salivation, lacrimation, urination, defecation
What is the effect of a muscarine receptor agonist on the skin?
Vasodilation
Why does ACh have virtually no therapeutic applications?
It’s actions are diffuse, rapid hydrolysis via AChe and BChe
What muscarinic agonist can be taken orally for post operative abdominal distinction and has the effects of increasing the contractile force of smooth muscle throughout the gastrointestinal tract?
Bethanecol
What are 3 examples of muscarinic agonists?
Bethanecol, methacholine, pilocarpine
What muscarinic agonist taken orally is used in gastric atony and increases the force of gastric contractions?
Bethanechol
What muscarinic agonist taken subcutaneously is used for non obstructive urinary retention and increases smooth muscle contractions of the bladder body?
Bethanechol
What muscarinic agonist is used in the diagnoses of asthma by causing Bronchoconstriction and broncho secretion that could trigger an asthmatic event in a patient with asthma also has slight susceptibility to ChE?
Methacholine
What muscarinic agonist can be taken orally for xerostomia (dry eye/mouth) and facilitates lacrimal and salivary secretions?
Pilocarpine
What muscarinic agonist instilled into the eye is used to treat glaucoma by increased drainage of aqueous humor and relieves intraocular pressure
Pilocarpine
Glaucoma is characterized by too much pressure buildup in what part of the eye causing the lens to be pushed back into the retina?
Anterior chamber
Where does the aqueous humor drain?
Canal of schlemm
What are the two mechanisms behind glaucoma?
Too much production
Not enough drainage
What is characterized by an increase in intraocular pressure, leads to damage of ocular disk and irreversible blindness, leading cause of blindness in African Americans and third leading cause in Caucasians?
Glaucoma
What are the two types of glaucoma?
Narrow angle (acute congestive) Wide angle (chronic simple)
What type of glaucoma requires drug treatment for management of an acute attack?
Narrow angle (acute congestive)
What type of glaucoma has a gradual insidious onset and requires chronic drug therapy?
Wide angle (chronic simple)
How do muscarinic agonsts (pilocarpine) lead to increased drainage of the aqueous humor by widening the canal of schlemm and decreasing ocular pressure?
Mimics PNS by causing ciliary muscle to contract/accomodation (when ciliary muscle contracts it opens canal of schlemm wider)
Why are bethanechol and pilocarpine therapeutically useful muscarinic agonists?
Resistant to ChE
Limited or no nicotinic activity
Retain activity at relevant organ systems
What muscarinic agonist has miotic action useful in reversing a narrow angle glaucoma attack, reversing mydriasis produced by atropine and some usefulness in wide angle glaucoma?
Pilocarpine
What are some contraindications of muscarinic agonist use?
Asthma - increase bronchial secretion and smooth muscle contraction precipitating asthma attack
Peptic ulcer disease - increase acid secretion
Sweating, abdominal cramps, difficulty in visual accommodation, salvation
Atropine is a plant alkaloid and potent selective muscarinic receptor antagonist from what plant?
Atropa Belladonna
What blocks M3 muscarinic receptors in the eye, which blocks ACh action on circular fibers causing circular fibers to relax and pupil diameter to increase?
Atropine
Muscarinic receptor antagonists inhibit what branch of the ANS?
PNS
Why is there slight cardiac slowing with small doses of atropine?
Regulatory muscarinic receptors that regulate PNS if these are blocked PNS works better
The effects of atropine are consistent with what?
PNS inhibition
What are 4 muscarinic receptor antagonists?
Atropine, scopolamine, ipratropium, pirenzipine
What muscarinic receptor antagonist has some selectivity for M1 receptors over M2 or M3?
Pirenzipine
How does one overcome the lack of selectivity for the muscarinic receptor antagonists?
Local administration (ex: pulmonary inhalation, installation into the eyes)
What was historically used for the treatment of peptic ulcers, has some selectivity for M1 now largely replaced by H. Pylori therapy, H2 antagonists, and proton pump inhibitors?
Pirenzipine
What muscarinic antagonist is used to treat irritable bowel syndrome, can reduce tone and motility throughout gut tract, limited usefulness in many cases?
Atropine
What muscarinic receptor antagonist is used to treat urinary disorders?
Oxybutynin ( glycopyrrolate, methscopolamine)
What muscarinic antagonist is used to treat mild cystitis? ( anti microbial therapy essential in bacterial cystitis)
Oxybutynin ( glycopyrrolate, methscopolamine)
What muscarinic receptor antagonist can be taken orally or via catheter to treat bladder spasm, post surgical prostatectomy and neurologic disease?
Oxybutynin ( glycopyrrolate, methscopolamine)
What muscarinic receptor antagonist is used in chronic obstructive pulmonary disease COPD and asthma, blocks all muscarinic receptor subtypes, has minimal inhibitory effect on mucocilliary clearance relative to atropine?
Ipratropium
What muscarinic antagonist has parenteral administration, tachycardia, bronchodilation, and inhibition of secretion?
Ipratropium
What muscarinic antagonist when inhaled actions confined almost exclusively to mouth and airways, 90% of inhaled drug is swallowed, has very inefficient absorption from GI tract and has the common side effect of dry mouth?
Ipratropium
What muscarinic antagonist has some utility in asthma but limited can provide virtually complete protection against Bronchoconstriction produced by subsequent inhalation of substances such as cigarette smoke, not as effective against stimuli such as histamine, bradykinin or prostaglandin
Ipratropium
What muscarinic receptor antagonist is used in ophthalmology to induce mydriasis (pupil dilation- often required for thorough examination of retina and optic disc) and cyclogia (paralysis of ciliary muscle)?
Atropine
What muscarinic receptor antagonist is used to treat motion sickness, the patch (TRANSDERM SCOP) delivers 0.5mg of this drug over 72 hours
Scopolamine
What muscarinic receptor antagonist is used to treat poisoning by muscarine containing mushrooms?
Atropine
What stimulation can result in complex and often unpredictable series of effects, wide range of systems affected: skeletal NMJ, autonomic ganglia, CNS, stimulation can desensitize receptors leading to excitation at low doses and block at high doses?
Nicotine
Low doses stimulate, larger doses result in initial stimulation followed by very quick longer lasting blockade of transmission also increased heart rate, blood pressure, increase in GI motility describes what?
Nicotine effect on ANS
Similar to ANS, stimulant phase usually obscured by rapidly developing paralysis describes what?
Nicotine effect on NMJ
Effective stimulant, high dose stimulation followed by depression-central paralysis, chemoreceptor trigger zone stimulation- vomiting
Nicotine effect on CNS
What amount of acute nicotine is fatal in adults?
60mg
What are 4 things to treat nicotine toxicity?
Induce vomiting
Gastric lavage (stomach pump)
Respiratory assistance
Treatment of shock
