Exam 1 Drugs: Muscarinics (31) Flashcards
1
Q
Acetylcholine
A
- Agonist
- Quaternary, short t1/2
- topical use to induce miosis
- adverse: hypotension, brady, flushing, dyspnea, corneal edema & clouding
- do not know about safety in children
2
Q
Methacholine
A
- Agonist
- Quaternary, highly resistant to AChEs
- > duration and selectivity than ACh
- slight nicotinic action
- used for diagnosis of bronchial airway hyperreactivity (inhalation via nebulizer, airway constricts)
- adverse: dyspnea, lightheadedness, headache, pruritis, throat irritation
- contra: recent heart attack/stroke, aortic aneurysm, uncontrolled hypertension
3
Q
Bethanechol
A
- Agonist
- Quaternary, completely resistant to AChEs (long duration of action)
- almost completely selective for muscarinic action
- treats urinary retention (w/o obstruction)
- stimulates GI peristalsis post-op (not used for this anymore)
- adverse: sweating, shivering, nausea, dizziness, increased freq urination, rhinitis
- contra: acute iritis or glaucoma after cataract extraction, narrow-angle glaucoma
4
Q
Carbachol
A
- Agonist
- Quaternary, completely resistant to AChEs (long duration of action)
- substantial nicotinic activity (cannot be used systemically because of unpredicable activity)
- low antagonism by atropine
- used topically to reduce pressure in glaucoma (and induce miosis)
- adverse: sweating, shivering, nausea, dizziness, increased freq urination, rhinitis
- contra: acute iritis or glaucoma after cataract extraction, narrow-angle glaucoma
5
Q
Pilocarpine
A
- Agonist
- Tertiary, dominant muscarinic action
- treatment of xerostomia from Sjogren’s Syndrome by increasing secretions
- secretions increased at sweat glands and salivary
- also a miotic agent
- taken orally for xerostomia, topically for glaucoma treatment (MOSTLY TREATS XEROSTOMIA)
- adverse: SWEATING, shivering, nausea, dizziness, increased freq urination, rhinitis
- contra: iritis or glaucoma following cataract removal, narrow angle glaucoma
- may cause CV pressor effects
6
Q
Cevilimine
A
- Agonist
- Tertiary, high affinity M3 (more specific than Pilocarpine)
- this affinity enhances both lacrimal and salivary gland secretion
- treats Sjogren’s Syndrome xerostomia
- longer lasting and fewer side effects than pilocarpine
7
Q
Metaclopramide
A
- Dopamine ANTAgonist
- tertiary
- treats GERD and prevention of chemo-induced emesis (vomiting)
- adverse: extrapyramidal effects (serious), restlessness, drowsy, fatigue, nausea, xerostomia, diarrhea, constipation
- contra: pheochromocytoma (tumor that releases Nor and EP), seizure disorders, patients taking anti-psychotics that could cause extrapyramidal effects
- chronic use could lead to tardive dyskinesia (epe)
8
Q
Atropine
A
- Antagonist
- tertiary, naturally occurring, does not cross BBB at therapeutic doses, long acting (5-6 days)
- mainly muscarinic action, marginal nicotinic
- used to treat Anti-ChE overdose, acute brady, excessive salivation, mucus secretion during surgery, premed anesthesia procedure, antidote for mushroom poisoning
- more effective at reversal of exogenous cholinergic activity than endogenous
- systemic dose: no occular effect, topical: 7-12 days
- adverse: cardiac arrythmia, coma, resp depression, raised intraoccular pressure (all serious). Also tachy, constipation, xerostomia, blurred vision
- contra: narrow angle glaucoma
- toxic doses cause atropine flush (dilates cutaneous blood vessels)
- infants and elderly: low doses may not accelerate heart
- Generally CNS stim followed by depression (exception HR slow @ v low doses)
9
Q
Scopalamine
A
- Antagonist
- tertiary, crosses BBB
- CNS effects @ much lower doses compared to atropine and faster onset
- treatment of motion sickness, nausea, and vomiting
- causes CNS depression w/ drowsiness, amnesia, fatigue, dreamless sleep
- also causes euphoria so subject to abuse
- adverse: HR increased, drug induced psychosis (both serious), also somnolence, xerostomia, blurred vision
- contra: narrow angle glaucoma
- delivery: transdermal patch
10
Q
Homotropine
A
- Antagonist
- tertiary, semisynthetic deriv of atropine
- duration 12-24 hrs
- uses: mydriasis and cycloplegia for refraction. treat acute inflammatory conditions of the uveal tract
- adverse: increased intraoccular pressure, systemic antichol effects with repeat dosing (both serious), also local irritation, vascular congestion, edema, exudate, eczema
- contra: narrow angle glaucoma
- Homotropine Methyl Bromide: quaternary deriv of homotropine (use in combo with hydrocodone as antitussive agent) (less potent than atropine in anti-muscarinic, but 4x more potent in ganglionic blocking)
11
Q
Cyclopentolate
A
- Antagonist
- tertiary, fast acting (effect maximal 15-60 mins, recovery w/in 24 hrs)
- produces mydriasis and cycloplegia
- adverse: increased intraoccular pressure, systemic effects w/ repeat dosing (both serious), also: local irritation, vascular congestion, edema, exudate, eczema
- contra: narrow angle glaucoma
- often used pediatric
12
Q
Tropicamide
A
- Antagonist
- shorter half life than atropine (15-60mins), preferred to atropine, may need two doses and examination within 30 mins
- induces mydriasis for fundus examination and cycloplegia for refraction
- preferred when short procedure/don’t need full cycloplegia
- adverse: increased intraoccular pressure, CV events and death when used with hydroxyamphetamines (both serious), also stinging, blurred vision, photophobia
- contra: narrow angle glaucoma
13
Q
Dicyclomine
A
- Antagonist
- tertiary, half life 1.8 hours but action up to 6
- treats IBS and minor diarrhea
- adverse: increased intraoccular pressure, tachy (both serious), also urinary retention, confusion
- contra: narrow angle glaucoma, GI or urinary obstruction, Myasthenia Gravis
14
Q
Hyoscamine
A
- Antagonist, belladonna alk
- longer action than Dicyclomine
- treats peptic ulcer disease, IBS, hypermotility disorders (GI and bladder), infant colic
- adverse: increased intraoccular pressure, tachy, and palpitations (all serious), also xerostomia, urinary hesitancy and rentention, blurred vision, mydriasis
- contra: narrow angle glaucoma, myasthenia gravis
15
Q
Methscopolamine
A
- Antagonist
- Quaternary amonium deriv of Scopolamine
- less potent than atropine, poorly absorbed
- treats peptic ulcer disease as an alternative or added therapy
- adverse: cardiac arrhythmia, malignant hyperthermia, anaphylaxis, seizure (all serious), also constipation, xerostomia, urinary retention, increased sweating
- contra: GI obstruction, narrow angle glaucoma
- delayed but measurable CNS and cognitive anti-chol effects
