Anti-Muscarinics Flashcards
Anticholinergics include
anti-muscarinics and ganglionic blockers
Atropine
- Reverse muscarine or ACh inhibition poisoning
- long lasting pupil dilation (for ophth exams)
- anti-diarrheal (mixed with opiod) = lomotil
- prevent M side effects in patient receiving ChE inh for myesthenia gravis.
- intestinal spasms/pain
- reduction of GI secretions
- alt for amblyopia (pharmacological patch)
- 3 amine so CNS effects
Scopolamine
- motion sickness
- cause drowsiness
- patch
- 3 amine so CNS effects
Tropicamide
- short acting
- pupil dilation
- cyclopentolate and homatropine are similar
Cyclopentolate
-Similar to homatropine and tropicamide
Homatropine
-Similar to tropicamide and cyclopentolate
Ipratropium
- quart amine
- administered by inhalation
- COPD – bronchodilation
- tiotropium is similar but longer lasting
Tiotropium
similar to Ipratropium but longer lasting
Tolterodine
- Antag at bladder mAChRs
- Overactive bladder, nocturia and incontinence
Dicyclomine
- GI mAChRs – so relaxes the intestinal smooth muscle
- Overactive bowel
Glycopyrrolate
- used preop to inh secretion
- inh sweating
- inh M overshoot after ChE inhibition (prevent M side effects for patient on neostigmine)
Benztropine
- lipid soluble
- relieves extrapyramidal effects in Parkinson’s patients or antipsychotic patients
What side effects to they block
DUMBELS and SLUD
salivation, lacrimation, urination, defecation
effects of increasing doses of atropine
0.5- dry mouth and decreased sweating
1- incr HR, very dry mouth and thirst
2- blurred vision, tachycardia and palpitations
5- urinary retention, hot and dry skin, restlessness and fatigue
10- rapid and weak pulse, ataxia, hallucinations, delirium and coma
affects of atropine overdose
hot as a hare (decr sweating, incr temp) mad as a hatter (confusion, delirium) red as a beet (flushed face, tachycardia) dry as a bone (decr secretions, thirsty) blind as a bat (pupil dilation)
contraindications
glaucoma
classes of other drugs with anti M activity
- sedating antihistamines
- tricyclic antidepressants
- phenothiazine antipsychotics
- older NMB
- Quinidine
- Meperidine
Anti-muscarinics
so they have symp because allows symp influence to become predominant.
Often distinguished by the duration of action and lack of CNS penetrance
ocular effects of atropine
- mydriasis - relaxes the iris sphincter, which allows symp tons to predominate on radial muscle.
- blocks accommodation- relaxes/paralyzes the ciliary muscle, which increases tension on the ligaments, thereby flattening the lens.
- inhibits lacrimation
cardiac effects of atropine
- standard doses may incr HR and antrioventricular conduction
- very low doses may initially decrease HR by first blocking presyn Rs
respiratory effects of atropine
- bronchodilation
- inhibit secretions
GI and urinary tract effects of atropine
- relaxes gastrointestinal tone, (not sphincters) prolonging intestinal transit time.
- inh gastric acid secretion
- relaxes detrusor muscle of bladder causing urinary retention.
CNS affects of atropine
- first causes stimulation, followed by a sedating effect
- high doses can cause confusion and/or hallucinations
other effects of atropine
inh sweating, possible leading to hyperthermia
short acting mydriatic agents
Tropicamide, cyclopenolate, homatropine
antiM adverse effects
Dry mouth (xerostomia), blurred vision, hot/flushed skin, constipation, difficulty urinating, tachycardia, confusion, sedation
diphenhydramine
Antihistamine with anti-muscarinic activity
tricyclic anti-depressants
Class of drug with anti-muscarinic activity
chlorpromazine
Antipsychotic with anti-muscarinic activity
amblyopia
Atropine is an alternate treatment to the eye patch
low doses of atropine
Produce dry mouth and decreased sweating
mod doses of atropine
Produces increased heart rate, blurred vision, possible urinary retention
high doses of atropine
Produces rapid and weak pulse, ataxia, hallucinations, delirium and coma
The effect of Atropine on bradycardia
Blocks M2 receptors allowing B1 receptors to predominate at the cardiomyocyte
SLUD
Mnemonic for adverse actions of antimuscarinics; blocks salivation, lacrimation, urination, defecation
DUMBELS
Mnemonic for Diarrhea, Decreased blood pressure, Urination, Miosis, Bronchoconstriction and Bradycardia, Excitation of skeletal muscle, Lacrimation, and Salivation and Sweating
oxybutinin
Antimuscarinic used for overactive bladder; main side effects are dry mouth and constipation; contraindicated for narrow-angle glaucoma.
