Autonomic Drugs Flashcards
Acetylcholine
- direct cholinoceptor agonist; N or M, but doesn’t cross fat
- rapidly degraded
- administration: IV, bc not lipophilic, so poorly absorbed in GI tract
- used for:
1. Miosis (short-lived ) in eye surgery
2. provocation test in coronary angiography
Methacholine
- direct cholinoceptor agonist; choline ester; quaternary amine
- longer half-life
- used for bronchial challenge
Carbachol
- direct cholinoceptor agonist; choline ester; quaternary amine; topical use; N and M receptors (N
Bethanechol
- direct cholinergic agonst; choline ester; quaternary amine;
- not susceptible to AChE
- acts on M3 (used for GI/GU), weak M2
- used for urinary retention, gastric emptying abnormalities
- NOT FOR OBSTRUCTION
Muscarine
- direct cholinergic agonist; muscarinic alkaloid; acts on muscarinic recpetors
- not susceptible to AChE; long half-life; very potent
- seen in poisoning; not therapeutic
- salivation, tear flow
- abdominal pain, nausea, diarrhea, blurred vision
- resolve within 2 hrs
Pilocarpine
- direct cholinergic agonist; muscarinic alkaoid; tertiary amine with poor systemic absorption
- topical for eyes
- M3 predominates; DRUG OF CHOICE FOR GLAUCOMA
Quinidine
- antiarrhythmic
- has antimuscarinic properties
Procainamide
- antiarrhythmic
- antimuscarinic properties
TCAs
- anti-depressant, decreases catecholamine metabolism, increasing concentration at synaptic cleft
- antimuscarinic properties
Nicotine
- direct cholinoceptor agonist; acts on nicotinic receptors
- varying effects
- Nm receptor: depolarizing blockade, Ca++ rushes in, leads to fasciculations, spasm
- Nn receptors; depends on predominate stimulation
- Cardiac: increased HR, etc due to catecholamine release from stimulated adrenal medulla
- Vasculature: peripheral vasoconstriction
- GI: increased motility, secretion
Contraindications to cholinoceptor agonists
- asthma
- peptic ulcers
- GI tract disorders
Edrophonium
- indirect cholinoceptor agonist (AChE inhibitor); used for diagnosis of MG
- short acting
- given IV
Neostigmine, pyridostigmine
- indirect cholinoceptor agonist (AChE inhibitor); quaternary amine (no CNS)
- uses:
- ileus
- urinary retention
- treatment of myasthenia gravis
- reversal of succinyl choline
Physostigmine
- indirect cholinoceptor agonist (AChE inhibitor); tertiary amine so ENTERS CNS
- used for:
- treatment of atropine
- glaucoma
Donepazil
- indirect cholinoceptor agonist (AChE inhibitor); lipid soluble
- use for:
- treatment Alzheimers
Tacrine
- indirect cholinoceptor agonist (AChE inhibitor); lipid soluble
- use for:
- treatment Alzheimers
Echothiophate
- irreversible AChE inhibitor; lipid soluble, long acting
- is almost poison; instead treats glaucoma
Malathion
- irreversible AChE inhibitor; lipid soluble, long acting
- insecticide; v bad. treat with atropine
Parathion
- irreversible AChE inhibitor; lipid soluble, long acting
- insecticide; v bad. treat with atropine
Sarin
- irreversible AChE inhibitor; lipid soluble, long acting
- this is nerve gas. awkward.
Atropine
- is a blocker! tertiary amine (enters CNS); all the different M inhibitors; competes with AChE
- progression from
- mydriasis and cycloplegia (can’t accommodate)
- hyperthermia
- tachycardia
- sedation
- urinary retention
- hallucination
minimal effect on BP along, because sympathetic tone predominates
uses:
- antispasmodic
- anti-secretory
- anti-diarrheal
if intox:
- sx
- physostigmine
ipratropium
properties: nonselective muscarinic inhibitor, but inhaled affects M3; quaternary amine
Effects: decreases bronchoconstriction, secretions
uses: first for COPD, second for asthma flares
benztropine
properties: cholinergic inhibitor; tertiary amine so CNS absorption; acts on brain M receptors
Effects: re-establish dopaminergic-cholinergic balance
- decrease GI/GU secretions
- increased heart rate
Use:
- Parkinson’s treatment (2nd line)
- decrease bad effects antipsychotics
hexamethonium, mecamylamine
nicotinic cholinergic inhibitors; no longer used because of toxicities
-reduce predominant autonomic tone
