Reversal of anticholinergic induced CNS toxicity cholinergic drugs
Drugs that block skeletal neuromuscular junction are often used during general anesthesia to maintain SM paralysis during surgery
Indirect acting cholinergic stimulants inhibit cholinesterase enzyme at neuromuscular junction allowing endogenously released Ach to remain active at the synaptic site and overcome the neuromuscular blockade until the curarelike agents have metabolized
Reversal of neuromuscular blockage
Indirect acting cholinergic stimulants
----Reverse toxic effects of anticholinergic drugs
Inhibit Ach breakdown allowing endogenously released Ach to overcome anticholinergic drugs
Adverse Effects Cholinergic Drugs
GI distress
Increased salivation
Bronchoconstriction
Bradycardia
Visual problems
Exaggerated during parasymp activity
Anticholinergic Drugs
Attempt to diminish response to cholinergic stimulation
Competitive antagonists of the postsynaptic cholinergic receptor but doesn’t activate it
----Binding blocks the receptor from the effects of the endogenous Ach, diminishing the cellular response to cholinergic stimulation
Categories
----Antimuscarinic and antinicotinic agents
--------Most common: atropine
Anticholinergic drugs Mechanism of Action
Preferential for certain muscarinic receptors
Specificity is not exclusive therefore other tissues affected as well
Antagonize GI muscarinic receptors
Other drugs work on the ENS cholinergic synapses
GI disorders anticholinergic drugs
Blocks effects of endogenous Ach release
Antispasmodic drugs: Decrease GI smooth muscle tone or spasms
Parkinson disease
Caused by deficiency in dopamine in basal ganglia
Leads to overactivity of ventral cholinergic synapses
Cardiovascular system
Block effects of vagus nerve on myocardium
Ach slows HR and conduction of action potentials
----Atropine reverses these effects
Cholinergic poisoning
Inhibit the Ach-e enzyme throughout the body causing overstimulation of nicotinic and muscarinic receptors inf organs
Eye
Block ach mediated contraction of pupillary sphincter muscle causing dilatation (mydriasis)
Motion sickness
Block cholinergic transmission from the brain and brainstem related nausea and vomiting
Administered trans dermally via patches
Preoperative med
Decrease respiratory secretions during general anesthesia
Respiratory tract
Vagus nerve causes bronchoconstriction
Anticholinergic drug blocks effects of vagal releases Ach and relax smooth muscle
Urinary tract
Atropine
Elevate urinary frequency and incontinence by causing hypertonicity of bladder reducing contraction of the bladder detrusor muscle; allowing the bladder to fill more normally
Adverse Effects anticholinergic drugs
Cant be targeted for one specific organ without also achieving response in other tissue