Term
| what are the three types of anticholinergic drugs? |
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Definition
| antimuscarinics (atropine, propantheline - inhibit cholinergic transmission at postganglionic para-sympathetic receptor sites), ganglionic blocking agents (mecamylamine, trimethaphan - block cholinergic transmission at autonomic ganglia in both parasympathetic and sympathetic nerve fibers), and neuromuscular blockers (not covered this year) |
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Term
| what is the term anticholinergic primarily used to denote? |
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Definition
| muscarinic (G-protein coupled) blockers, which have relatively selective blocking action |
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Term
| what happens with an overly large dose of any of the anticholinergics? |
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Definition
| loss of specificity of receptor blocking action - wide range of ADRs |
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Term
| what are the major organs affected by anticholinergic drugs? |
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Definition
| since parasympathetic nerves are distributed throughout the body, anticholinergic drugs can affect the eye, resp tract, heart, GI tract, urinary bladder, most nonvascular smooth muscle, exocrine glands and the CNS |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the GI? |
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Definition
| decreased motility, secretions -> constipation (interfernce with vagal control) |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the CV? |
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Definition
| tachycardia (though small doses of atropine can produce bradycardia) |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the urinary tract? |
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Definition
| contraction of the sphincter muscle/relaxation of detrusor muscle, resulting in urinary retention |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the eye? |
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Definition
| relaxation of the ciliary muscle: cyclopelagia (paralysis of accomodation), relaxation of the sphincter muscle: mydriasis (excessive dilation of the pupil) - relaxation for the fundoscopic exam |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the exocrine glands? |
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Definition
| decreased sweating, salivation and mucous formation (problem in geriatric pts with swallowing) |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the smooth muscle? |
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Definition
| relaxation of non-vascular smooth muscle (biliary, bronchiolar, intestinal, uterine) |
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Term
| what are the major pharmacologic effects of anticholinergic drugs on the CNS? |
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Definition
| decreased sensitivity to motion, drowsiness, disorientation, possible hallucinations, decreased skeletal muscle activity (similar to alzheimer's) |
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Term
| what are the different kinds of muscarinic blockers? |
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Definition
| belladonna alkaloids, tertiary and quaternary amines |
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Term
| what are the principal naturally occuring anticholinergic drugs? |
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Definition
| the belladone alkaloids atropine and scopolamine. they are are similar but the oxygen added to scopolamine can make a patient a little more drowsy. cocain has a similar structur to atropine |
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Term
| what is the M/A for the belladonna alkaloids atropine and scopolamine? |
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Definition
| competetive antagonistic blockage of postsynaptic muscarinic ACh receptors. large doses block cholinergic transmission at autonomic ganglia and the neuromuscular junction. |
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Term
| how rapidly are belladona alkaloids absorbed? are they selective in blocking action of muscarinic receptors? can they penetrate the CNS? |
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Definition
| they are absorbed rapidly PO, they are relatively selective in blocking action at M receptor sites, and readily enter the CNS. there is a wide range however, of undesirable peripheral and central effects even when used therapeutically |
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Term
| what are uses of the belladonna alkaloids atropine and scopolamine in eye exams, preop, GI issues, myastenthia tx, allergies, and asthma? |
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Definition
| mydriasis and cycloplegia for eye exam, preop reduction of salivation/bradycardia, reduction of GI motility/secretions in cases of peptic ulcer, GI spasms, irritable bowel syndrome, or other GI disorders. reduction of muscarinic side effects assoicated with myasthenia anticholinesterase tx, relief of nasopharyngeal/broncial secretions associated with allergic disorders, relief of bronhoconstriction due to excessive parasympathetic nerve activity in bronchia asthma/other chronic obstructive pulmonary disease |
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Term
| what are uses of the belladonna alkaloids atropine and scopolamine in motion sickness, enuresis, sinus bradycardia/conduction block, sedation, cholinergic OD, and parkinsons? |
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Definition
| belladona alkaloids can be used in prevention/relief from motion sickness, treatment of enuresis as well as urinary urgency, tx of sinus bradycardia/conduction block due to excessive vagal tone, production to sedation/amesia (twilight sleep), antidoe to cholinergic OD/pesticides, relief of parkinsons symptoms and control of extrapyramidal disorders resulting from antipsychotic meds |
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Term
| how are the belladonna alkaloids absorbed? |
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Definition
| atropine and scopolamine are absorbed rapidly from the GI tract and eye. scopolamine is also absorbed significantly throuh the skin behind the ear when applied as a transdermal patch |
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Term
| what are belladonna alkaloid ADRs for the GI? |
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Definition
| dry mouth, vomiting, dysphagia, bloating, constipation, paralytic ileus, possibly gastroesophageal reflux |
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Term
| what are belladonna alkaloid ADRs for the CV? |
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Definition
| tachycardia, facial flushing, HTN |
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Term
| what are belladonna alkaloid ADRs for the CNS? |
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Definition
| headache, confustion, drowsiness, nervousness, restlessness, insomnia, delirium, hallucinations, elevated body temp |
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Term
| what are belladonna alkaloid ADRs for the eye? |
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Definition
| blurred vision, photophobia, cycloplegia, increased intraocular tension |
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Term
| what are belladonna alkaloid ADRs for the skin? |
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Definition
| rashes, urticaria, systemic allergic reactions |
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Term
| what are belladonna alkaloid ADRs for the GU? |
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Definition
| urinary retention, dysuria, impotence |
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Term
| what are other general belladonna alkaloid ADRs? |
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Definition
| reduced sweating, suppression of lactation, possible respiratory depression |
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Term
| what are possible contraindication for belladonna alkaloids? |
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Definition
| narrow angle glaucoma, *severe coronary artery disease, GI obstruction/intestinal atony/paralytic ileus/hepatic disease/ulcerative colitis, renal obstruction/disease, and myasthenia gravis |
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Term
| what drugs can increase the effects of the belladona alkaloids? |
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Definition
| antihistamines, tricyclic anti-depressants, antipsychotics, anti-anxiety drugs, quinidien, procainamide |
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Term
| what drugs can decrease the effect of the belladonna alkaloids? |
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Definition
| antacids that can impair GI absorption |
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Term
| what drugs might antimuscarinics enhance the effects of? |
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Definition
| bronchodilators (adrenergics, theophylline) |
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Term
| what drug's effect might be decreased by antimuscarinics? |
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Definition
| cholinergics such as pilocarpine or physostigime |
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Term
| what are the tertiary amines? |
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Definition
| dicyclomine, oxybutin, oxyphencyclimine, cyclopentolate, tropicamide, benztropine, trihexyphenidyl, diphenhydramine, and ethopropazine |
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Term
| what are the benefits of the tertiary amines? |
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Definition
| they are well absorbed PO, have good lipid-solubility, and are widely distributed into peripheral/central tissues |
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Term
| what are the antispasmotic tertiary amine anticholinergics? |
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Definition
| dicyclomine for IBS, oxybutinin for bladder instability, and oxyphencyclimine for peptic ulcers |
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Term
| what are the mydriatic tertiary amines? what are they used for? |
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Definition
| cyclopentolate (24 hr duration) and tropicamide (6 hr duration) are used to produce mydriasis/cycloplegia for eye exams b/c they have shorter durations than the belladona alkaloids |
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Term
| what are possible ADRs for the mydriatic tertiary amines? |
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Definition
| disorientation, retrograde amnesia, hallucinations, cardiac arrhythmias (a-fib/supraventricular tachycardia), and death in children |
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Term
| what are the antiparkinson's/anti-extrapyramidal disorder tertiary amine anticholinergics? how do they work? |
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Definition
| benztropine, trihexyphenidyl, diphenhydramine, and ethopropazine are used to balance ACh and dopamine (parkinsons = dopamine deficiency, extrapyramidal disorders = dopamine blockage) these are more selective than belladonna alkaloids. |
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Term
| what are the peripheral ADRs associated with the antiparkinson's/anti-extrapyramidal disorder tertiary amine anticholinergics? |
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Definition
| constipation, urinary retention, and tachycardia |
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Term
| what is benztropine used for? trihexyphenidyl? |
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Definition
| **benztropine: initiation of therapy, trihexyphenidyl: maintenance of therapy |
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Term
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Definition
| benadryl, an antihistamine with central anticholinergic activity. it has less peripheral side effects than other agents, and has a sedative effect |
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|
Term
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Definition
| a antiparkinson's/anti-extrapyramidal disorder tertiary amine with a high degree of peripheral anticholinergic action and less efficacy than other agents |
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Term
| what are the quaternary amines? what are they mainly used for? |
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Definition
| clindinium, glycopyrrolate, methantheline, and propantheline which are mainly used for reduction of gastric acid secretion in tx of peptic ulcers. they can also be used for decreasing GI/bile motility in spastic disorders, and decreasing motility of urinary tract in a hypertonic neurogenic bladder |
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Term
| what are problems with the quaternary amines? |
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Definition
| low degree of lipid solubility, poor/erratic adsorption, and limited systemic distribution (do not cross BBB) |
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Term
| what is seen with small doses of quaternary amines? |
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Definition
| inhibition of sweating, salivation, and bronchial secretions. *smaller doses will inhibit secretions but not the target |
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Term
| what is seen with medium doses of quaternary amines? |
|
Definition
| mydriasis, cycloplegia, tachycardia, decreased gastric acid secretion, decreased GI/urinary motility |
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Term
| what is seen with large doses of quaternary amines? |
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Definition
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Term
| what is glycopyrrolate used for? |
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Definition
| preanesthetic used to decrease saliva, reduce secretions of GI/resp tracts, prevent bradycardia, and reduction of gastric acid secretion in treatment of peptic ulcers |
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Term
| when is methantheline used? propantheline? |
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Definition
| methantheline is usually used for tx of hypertonic neurogenic bladder, propantheline is more potent. both can also be used for reduction of gastric acid secretion in treatment of peptic ulcers |
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Term
| what is clindinidum used for? |
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Definition
| reduction of gastric acid secretion in treatment of peptic ulcers |
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Term
| how are ganglionic blocking agents generally classified? what are the 2 kinds of ganglionic blocking agents? |
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Definition
| anticholinergic drugs that act *primarily at postsynaptic cholinergic sites within autonomic ganglia are termed ganglionic blocking agents and they are divided into depolarizing and nondepolarizing categories. |
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Term
| what is a depolarizing ganglionic blocking agent? |
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Definition
| nicotine, an alkaloid, which intially stimulates the postsynaptic ganglionic receptor causing elevated BP, HR, GI motility, CNS stimulation and respiration - but with large doses and systemic absorption, repolarization of the membrane can be prevented - blocking stimulation and leading to reduced BP, increased HR, confusion, convulsions, and respiratory failure |
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Term
| how do the non-depolarizing ganglionic blocking agents work? |
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Definition
| nonselective (both symp and parasymp) competetive antagonism of ACh at receptor sites of ganglia in the ANS |
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Term
| what are the net effects of non-depolarizing ganglionic blocking agents? |
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Definition
| the net effects are dependent on which division of the ANS has primary control of the organ/system. if symp: marked vasodilation, (orthostatic hypotension), and decreased venous return (decreased cardiac output). parasymp: decreased GI motility/secretions, dry mouth, urinary retention, constipation, cycloplegia & mydriasis, and impotence |
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Term
| what are the two non-depolarizing ganglionic blocking agents? |
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Definition
| mecamylamine and trimethaphan which are powerful BP reducing drugs but are infrequently used due to the wide range of side effects |
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Term
| what is mecamylamine used for? |
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Definition
| mecamylamine has good absorption from the GI and enteres the CNS. management of moderate to severe essential HTN and uncomplicated malignant HTN when other antihypertensive drugs have failed |
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Term
| what are contraindications for mecamylamine use? ADRs? |
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Definition
| ADRs are consistent with those usually seen with anticholinergics, and contraindications are for coronary insufficiency and recent MI. rapid termination should be avoided due to possible occurence of HTN rebound |
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|
Term
| what is trimethephan often used for? |
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Definition
| if a pt has a hypertensive crisis |
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Term
| what are other effects of trimethaphan? |
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Definition
| direct relaxant effect on vascular smooth muscle and histamine release |
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Term
| how is trimethaphan in terms of duration of action and interactions with other drugs? |
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Definition
| it works for 10-30 min and has a physical incompatibility with other IV solutions (does not mix) |
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Term
| what are restricted uses of trimethaphan? |
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Definition
| producing controlled hypotension during sx, acute control of BP in HTN emergencies, and control of blood pressure in cases of acute dissecting aortic aneurysm |
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|
Term
| what are the ADRs associated with trimethaphan? |
|
Definition
|
|
Term
| what drugs can help with a trimethaphan OD? |
|
Definition
| phenylephrine and mephentermine: vasopressor drugs of choice to reverse significant hypotension |
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