Cholinergics
Drugs that stimulate parasympathetic nervous system (PNS).
Mimic parasympathetic neurotransmitter acetylcholine
Muscarinic recpetors (cholinergic)
stimulate smooth muscle and slow the heart rate
Nicotinic receptors (cholinergic)
(neuromuscular) affect the skeletal muscles
Why are many cholinergic agonists nonselective?
They can affect both the muscarinic and nicotinic receptors
Effects of cholinergics on eye
constrict pupil
Effects of cholinergics on lungs
constrict bronchioles and increase secretions
Effects of cholinergics on heart
decreased heart rate, blood vessels dilate
Effects of cholinergis on GI
increase peristalis and secretions, relax sphincters, cause urination
Effects of cholinergics on bladder
muscles contract
Effects of cholinergics on salivary glands
increased salivation
direct acting cholinergics
Selective to muscarinic receptors, nonspecific because muscarinic receptors are located in smooth muscles
Heart, GI, GU, glands
Bethanechol Chloride (Urecholine)
direct acting cholinergic agonist, acts on the muscarinic receptor, primarily used to increase urination
Metoclopramide HCL (Reglan)
direct acting cholinergic agonist, used to treat GERD
Metoclopramide
direct acting cholinergic agonist, increases gastric emptying time
Indirect acting cholinergic agonists
dont act on receptors, inhibit or activate the enzyme cholinesterase, permitting acetylcholine to accumulate at the receptor sites
Pilocarpine (Pilocar)
direct acting cholinergic, constricts pupils
Functions of indirect acting cholinergics
Break down cholinesterase enzyme into choline and acetic acid, Allow Ach to activate muscarinic and nicotinic cholinergic receptors
Effects of indirect acting cholinergics
Stimulate skeletal muscles, increase tone GI motility, bradycardia, miosis. Bronchial constriction, promote urination
Side effects of indirect acting cholinergics
bradycardia, asthma, peptic ulcers
Contradictions of indirect acting cholinergics
intestinal and urinary obstruction
Primary use of indirect acting cholinergics
treat myasthenia gravis, glaucoma, alzheimers, muscarinic antagonist poisoning
Use of Reversible cholinesterase inhibitors
Pupil constriction in glaucoma
Increase muscle strength in myasthenia gravis
Side effects of Reversible cholinesterase inhibitors
Muscle cramps, twitching, bradycardia, increase bronchial secretions
Anticholinergics
inhibit actions of acetylcholine by occupying the acetylcholine receptors
Effects of Anticholinergic drugs on heart
large doses increase P; small doses decrease P
Effects of Anticholinergic drugs on lungs
bronchodilation, decrease secretions
Effects of Anticholinergic drugs on GI
Relax smooth muscle tone, decrease motility and peristalsis, decrease secretions
Effects of Anticholinergic drugs on urinary tract
Relax detrusor muscle, increase sphincter constriction
Effects of Anticholinergic drugs on eyes
dilate pupils, decrease accommodation
Effects of Anticholinergic drugs on glands
decrease salivation, perspiration
Effects of Anticholinergic drugs on CNS
decrease tremors and rigidity of muscles. Drowsiness, disorientation, and hallucinations can result from large doses
Atropine (anticholinergic) action
Increase P, decrease motility and peristalsis, decrease salivary secretions
-Contraindicated in glaucoma
Atropine side effects
Tachycardia, palpitations, nasal congestion, flushing, photophobia, blurred vision, dry mouth and skin, abdominal distention, urinary retention, impotence
Atropine nursing interventions
Monitor vital signs, urine output, bowel sounds
Safety: use bedside rails, caution against driving motor vehicles
Provide mouth care and eye drops
Avoid hot environments
Avoid alcohol, cigarettes, caffeine, and aspirin at bedtime
Warn to wear sunglasses i
Antihistamines
Treats motion sickness
Scopolamine (Transderm Sc?p)
Dimenhydrinate (Dramamine)
Donepezil (Aricept)
AChE inhibitor - Alzheimer's disese
Antihistamine side effects
Dry mouth, visual disturbances, constipation, urinary retention, flushing, muscle weakness, tachycardia, hypotension
What is used for motion sickness?
anticholinergics ex)scopolamine
What is used for antiparkinsons?
trihexphenidyl HCl (cogentin)
biperiden lactate (akineton)
benzotropine
Atropine?
anticholinergic for IBS
nicotinic
parasympathetic targets, fast postsynaptic response
M1 - muscarinic
smooth muscles, glands of the gut-contraction and glandular secretion, slow
M2
smooth and cardiac muscles of cardiovascular system, contraction, intropic on cardiac muscle
M3
smooth muscles and glands, contraction and glandular secretion