Drugs Modulating ANS Function (Cholinergic and AntiCholinergic Drugs) Flashcards
What are the two Cholinergic Receptors
Nicotinic, Muscarinic
What drug are all muscarinic sites blocked by
Atropine
What drug blocks Effector cells of skeletal muscle innervated by somatic nerves
Curare
What drug blocks Autonomic ganglion cells of sympathetic & parasympathetic nerves
hexamethonium
What drug blocks Adrenal medullary cells and some adrenergic nerve terminals
hexamethonium
What are the locations of M1 receptors
CNS
Gastric Gland
Salivary Gland
What are the locations of M2 receptors
Heart
GIT
CNS
What are the locations of M3
Salivary Gland Gastric Gland Eye GIT Blood vessels
What drug inhibit Cholinesterase
Neostigmine
What drug inhibit AcH release by inhibiting synthesis
Hemicholinium- blocks choline uptake
Botulinium, Mg, aminoglycosides- inhibit release mechanism
What drug blocks the action of AcH
Atropine, Tubocurarine
What are the two types of Cholinergic Agonists
Direct Acting Agonist
Indirect Acting
What type of Cholinergic Agonist inhibit acetylcholinesterase
Indirect Acting
What substance may cause respiratory paralysis after large doses due to inhibition of presynaptic release of Ach & post-synaptic sensitization to Ach
Aminoglycosides
What are the two types of Cholinoreceptor activating drug
Choline ester, Alkaloids
What are the Choline Esters drugs
Acetylcholine
Metacholine
Bethanechol
What are the Alkaloid drugs
Pilocarpine
Muscarine
Nicotine
Labeline
What are the different types of cholinesterase inhibiting drugs
Alcohol
Carbamates
Organophosphates
What are some examples of Organophosphates
Therapeutics
Insecticides
Nerve Gases
True or false, the effects of AcH is short lived
True
What are the main receptors that acetylcholine act on
Muscarinic and nicotinic
Why are nicotinic effects not normally seen
Ach does not readily penetrate tissues which surround skeletal m & autonomic ganglia
What are adverse effects of AcH
Diarrhoea and decreased blood pressure Urination Miosis Bronchoconstriction & bradycardia Excitation of skeletal m Lacrimation Salivation & sweating
Nicotinic Effects of Acetylcholine can be protected based stimulation of nicotinic receptors on
Sympathetic and Parasympathetic Ganglia
Adrenal Medulla
Skeletal M
What is the therapeutic use of Acetylcholine
Miosis during ophthalmic sx
(rarely use b/c of widespread effects & rapid hydrolysis by cholinesterase
What are the adverse effects of Acetylcholine
Generalized cholinergic stimulation
What receptors does Acetylcholine activate
M, N
What is the therapeutic use of Bethanechol
Increases intestinal motility esp after sx. Stimulates detrusor m of bladder →used to treat urinary retention
What are the adverse effects of Bethanechol
Generalized Cholinergic Stimulation
What receptors does Bethanechol activate
M and some mild N properties
What is the therapeutic use of Methacholine
Diagnosis of asthma and bronchial hyperactivity
What are some adverse effects of Methacholine
Generalized cholinergic stimulation
What receptors does Methacholine activate
M
What is the therapeutic use of Pilocarpine
Very good at stimulating miosis & opening of trabecular meshwork around canal of Sclemn► used treatment of glaucoma
What are the adverse effects of Pilocarpine
Unlike other direct acting agonists, pilocarpine is able to enter brain & cause CNS disturbances -hallucinations, convulsions & generalized cholinergic stimulation
What receptors does Pilocarpine activate
M
Give an example of Cholinesterase inhibiting drug Alcohols
Edrophonium
Give an example of Cholinesterase inhibiting drug Carbamates : Teritiary Animes
Physostigmine
Give an example of Cholinesterase inhibiting drug Carbamates: Quaternary Ammoniums
Neostigmine
Pyridostigmine
Give an example of Cholinesterase inhibiting drug : Organophosphate: Therapeutics
Isoflurophate Echothiophate
Give an example of Cholinesterase inhibiting drug : Organophosphate Insecticides
Malathion
Parathion
Give an example of Cholinesterase inhibiting drug : Organophosphate Nerve Gases
Sarin
What is the therapeutic use of Physostigmine
For overdoses of atropine, phenothiazines, tricyclic antidepressants
What are the adverse effects of Physostigmine
Convulsions
Muscle paralysis secondary to overstimulation
Generalized cholinergic stimulation
What is the therapeutic use of Neostigmine
Treatment of myasthenia gravis
Treatment of urinary retention & paralytic ileus
Antidote for non-depolarizing neuromuscular blockade as with tubocurarine
What are the adverse effects of Neostigmine
Excessive cholinergic stimulation
True or false, Neostigmine actions are more prominent on CVS and eye than NMJ and GIT
False, more prominent on NMJ and GIT than CVS and eye
What is the therapeutic use of Endrophonium
Used to diagnose myasthenia gravis (MG). Not useful for maintenance therapy – short duration of action ( 5-15 min)
Used to differentiate MG from cholinergic crisis (excessive Ach)
True or False, In the test for Myasthenia Gravis, Edrophonium will drastically improve in patients with chollinergic weakness than Myasthenia Gravis
False, myasthenic weakness substantially improved by edrophonium; cholinergic weakness is aggravated
What is the therapeutic use of Pyridostigmine
Long duration of action
Used for long term treatment of myasthenia gravis
What is the adverse effects of Pyridostigmine
Excessive Cholinergic Stimulation
What organophosphate is not highly lipid soluble
Echothiophosphate
Recovery of enzymatic Activity in organophosphate depends on
Synthesis of new enzymes- process that may take weeks
What is used to treat organophosphate Toxicity
Support respiration
Very high doses of atropine (muscarinic receptor)
Cholinesterase reactivator- Pralidoxime
What are the different types of Neuromuscular blocks
Neuromuscular
Ganglionic
Muscarinic
What are the drugs associated with muscarinic blockers
Atropine Scopolamine Homatropine Cyclopentolate Tropicamide Pirenzepine
What are the types of Neuromuscular blockers
Non-depolarizing
Depolarizing
What are the drugs associated with ganglionic blockers
Nicotine
Hexamethonium
Trimethaphan
What are the therapeutic uses of atropine
Treatment of bradycardia
Mydriasis & Cycloplegia
Gastrointestinal spasms
Organophosphate poisoning
What are the toxic affects of Atropine
Red as a beet , blind as a bat , dry as a bone , hot as a hare & mad as a hatter “
→ Cutaneous vasodilation → atropine flush , blurred vision ,
↓ secretions , hyperthermia ( atropine fever due to ↓ sweat ), delirium & hallucinations
What drug classes may have Anticholinergic side effects
Antihistamines Antipsychotics Tricyclic antidepressants Monoamine oxidase inhibitors ( MAOI ) Lithium
