Cholinergic Flashcards
Bella Donna Alkaloids
Antimuscarinic. Naturally occurring. Very potent. Includes atropine, hyoscyamine, scopalamine.
Atropine
Antimuscarinic. Used to treat tachycardia in critical care situations with pronounced vagal activity. Also used to dilate pupils, and as a pre-anesthetic topical prep (reduces respiratory secretions and facilitates intubation).
Hyoscyamine
Antimuscarinic. Used to treat overactive GI tracts (IBS, chronic gastric cramping).
Scopalamine
Antimuscarinic. Anti-nausea, anti-seasickness.
Synthetic antimuscarinics
Benztropine, Ipratropium
Benztropine
Antimuscarinic. Used to manage sx of movement disorders (e.g. extrapyramidal syndrome caused by antipsychotics and others)
Ipratropium
Antimuscarinic. Inhaled anticholinergic used to treat pts with COPD to keep secretions under control. Avoids taking a systemic anticholinergic.
Therapeutic effects M-receptor antagonists: ulcers
Selective blockage of the M1 receptors of parietal cells; inhibits acid secretion
Therapeutic effects M-receptor antagonists: asthma
Blockade of m-receptors on bronchioles SM inhibits the constricting effects of parasympathetic innervation. (Ipratropium)
Therapeutic effects M-receptor antagonists: 1st degree AV block
Blockade of m-receptors on the AV node prevents in an antagonistic fashion the slowing of conduction caused by the PSNS. This improves conduction in minor blocks (atropine).
Therapeutic effects M-receptor antagonists: pre-surgery
Inhibits secretions in the upper airways. Inhibits reflex-induced bradycardia and/or cardiac arrest during surgery. (atropine, glycopyrrolate)
Therapeutic effects M-receptor antagonists: IBS
Inhibits propulsive contractions and hypersecretion caused by PSNS. Use of quaternary ammonium derivatives retards absorption and limits systemic effects. (methscoplomine)
Quaternary derivatives
Antimuscarinic drugs that are polar, and therefore do not readily cross the blood brain barrier to enter the CNS.
Therapeutic effects M-receptor antagonists: hyperhidrosis
Inhibits sweating
Therapeutic effects M-receptor antagonists: ocular exams
Causes pupil dilation. (homatropine)
Therapeutic effects M-receptor antagonists: mushroom poisoning
Some mushrooms contain potent m-receptor agonists, which can cause hypersalivation, bradycardia, bronchospasm, hallucinations). Treated with atropine as antidote.
Therapeutic effects M-receptor antagonists: anticholinesterase poisoning
Anticholinesterases include insecticides and nerve gas. Atropine is used to treat ODs from these drugs.
Therapeutic effects M-receptor antagonists: motion sickness
Prophylactic effectiveness against motion sickness (scopolamine–lipid soluble, CNS effects).
Adverse effects M-receptor antagonists: tachycardia
Blockade of m-receptors in the SA node inhibits vagal effects on the heart. Tachycardia can result.
Adverse effects M-receptor antagonists: Xerostomia (dryness of the mouth)
Blockade of m-receptors in salivary glands inhibits salivation of vagal innervation.
Adverse effects M-receptor antagonists: blurred vision
Can inhibit actions of the ciliary muscles (control lens shape), and therefore cause blurry vision. (Cycloplegia: paralysis of accommodation). Also causes dilation of pupils.
Adverse effects M-receptor antagonists: Sedation
Anticholinergic agents that are lipid soluble can cross into the brain and have sedative effects.
Adverse effects M-receptor antagonists: Anhydrosis
Blockade of m-receptors on the sweat glands inhibit sweat production.
Adverse effects M-receptor antagonists:
Tachycardia, Xerostomia (dry mouth), blurred vision, sedation, anhydrosis (decrease in sweating).
Primary receptor at ganglia:
Nicotinic (Nn)