Pharmacology Cholinergic Drugs Lilley Chapter 20

acetylcholine

the neurotransmitter responsible for transmission of nerve impulses to effector cells in the parasympathetic nervous system

acetylcholinesterase

the enzyme responsible for the breakdown of acetylcholine (also referred to as cholinesterase)

Alzheimer's disease

a disease of the brain that is characterized by progressive mental deterioration manifested by confusion, disorientation, and loss of memory, ability to calculate, and visual-spatial orientation

atony

a lack of normal muscle tone

cholinergic crisis

severe muscle weakness and respiratory paralysis due to excessive acetylcholine; often seen in patients with myasthenia gravis as an adverse effect of drugs used to treat the disorder

cholinergic receptor

a nerve receptor that is stimulated by acetylcholine

miosis

the contraction of the pupil

muscarinic receptors

cholinergic receptors that are located postsynaptically in the effector organs such as smooth muscle, cardiac muscle, and glands supplied by parasympathetic fibers. stimulated by alkaloid muscarine a substance isolated from mushrooms

Nicotinic receptors

cholinergic receptors located in the ganglia (where presynaptic and postsynaptic nerve fibers meet) of both the parasympathetic nervous system and the sympathetic nervous; so named because they can be stimulated by the alkaloids nicotine

parasympathomimetics

drugs that mimic the parasympathethic nervous system; also referred to as cholinergic agonists.

parasympathetic nervous system

branch of the autonomic nervous system opposite the sympathetic

cholinergic drugs

primarily use for their effects on the GI tract, bladder and eye.

cholinergic drugs GI/bladder effects

stimulate the intestine and bladder which results in increased gastric secretions, gastrointestinal motility and urinary frequency

cholinergic drugs Eye effects

stimulate constriction of the pupil (miosis) and helps decrease intraocular pressure.

cholinergic drugs other effects

increased salivation and sweating, reduced heart rate and vasodilation, and causing the bronchi of the lungs to constrict and the airways to narrow

dosage effects

low doses stimulate the muscarininc receptors (desired), high doses stimulate the undesirable adverse effects of the nicotinic receptors

bethanechol (Urecholine)

Muscarinic (direct-acting) cholinergic agonist used postoperative and postpartum, functional urinary retention, bladder muscle atony

direct-acting cholinergic agonists

bind directly to cholinergic receptors and activate them

indirect-acting cholinergic agonists

stimulate the postsynaptic release of acetylcholine at the receptor site, then allows acetylcholine to bind to and stimulate the receptor.

cholinesterase inhibitors

work by inhibiting the action of acetylcholinesterase (the enzyme responsible for breaking down acetylcholine). There are two types reversible and irreversible

reversible cholinesterase inhibitors

bind to cholinesterase for a short period of time

irreversible cholinesterase inhibitors

bind to cholinesterase have a long duration of activity and the body must generate new cholinesterase enzymes to override the effects of the irreversible drug.

indirect-acting drug effects

cause skeletal muscle contraction and are used for the diagnosis and treatment of myasthenia gravis.

physostigmine (Antilirium)

indirect-acting anticholinesterase considered the antidote for anticholinergic poisoning as well as poisoning by irreversible cholinesterase inhibitors such as insecticides and tricyclic antidepressant overdose

donepezil (Aricept)

cholinesterase inhibitors used to treat Alzheimers, it increases acetycholine levels to help enhance and maintain memory and learning capabilities

contraindications of cholinergic drugs

known drug allergy, GI or GU tract obstruction, bradycardia, defects in the cardiac impulse conduction, hyperthyroidism, epilepsy, hypotension, or COPD.

adverse effects of cholinergic drugs

bradycardia, tachycardia, hypotension, hypertension, syncope, conduction abnormalities, HA, dizziness, convulsions, ataxia, abdominal cramps, increased secretions, N&V, diarrhea, increased bronchial secretions, bronchospasm, lacrimation, sweating, salivat

cholinergic crisis symptoms

circulatory collapse, hypotension, bloody diarrhea, shock and cardiac arrest. Early signs: abdominal cramps, salivation, flushing of the skin, N&V

SLUDGE

cholinergic poisoning, stands for
Salivation
Lacrimation
Urinary continence
Diarrhea
GI cramps
Emesis

interactions with cholinergic drugs

anticholinergics (atropine), antihistamines, and adrenergic agonists may antagonize and lead to a reduced response

pyridostigmine (Mestinon)

indirect-acting anticholinesterase use in myasthenia gravis and antidote for neuromuscular blocker toxicity

causes increased bladder tone and motility

what does bethanechol (urecholine) do?

peptic ulcer

what is a contraindication of bethanechol (urecholine)?

atropine (generic)

what is the antidote for accidental overdose of a cholinergic drug?

to aid in the diagnosis of myasthenia gravis?

what does edrophonium (Tensilon) do?

hypotension, syncope, dyspnea

what are some symptoms of cholinergic crisis?

B. Increased gastrointestinal motility

Cholinergic (parasympathomimetic) drugs have which therapeutic effect?
A. Urinary retention
B. Increased gastrointestinal motility
C. Mydriasis
D. Vasoconstriction

B. Lowering intraocular pressure in patients with glaucoma

Cholinergic (parasympathomimetic) drugs are indicated for which situation?
A. Treating a postoperative patient who has bradycardia
B. Lowering intraocular pressure in patients with glaucoma
C. Inhibiting muscular activity in the bladder
D. Preventing sali

B. urinary atony.

During postoperative teaching, the nurse explains that the patient is receiving bethanechol (Urecholine) to treat
A. postoperative hypotension.
B. urinary atony.
C. respiratory atelectasis.
D. postoperative ischemic colitis.

D. Headache

Which is an adverse effect of bethanechol (Urecholine)?
A. Constipation
B. Hypertension
C. Tachycardia
D. Headache

B. increase levels of acetylcholine in the brain by blocking its breakdown.

The nurse administering donepezil (Aricept) to a patient understands that the expected therapeutic action of this drug is to
A. relieve anxiety and restless behavior of the patient.
B. increase levels of acetylcholine in the brain by blocking its breakdow

B. Take the medication 30 minutes before meals.

When providing teaching to a patient diagnosed with myasthenia gravis, which instruction regarding the administration of physostigmine (Antilirium) is most appropriate?
A. Increase fluid and fiber in the diet to prevent constipation.
B. Take the medicatio

C. Alzheimer's disease

The provider has ordered donepezil (Aricept) for the patient, and the patient states "I have no idea why I take this medication." What is the most common diagnosis associated with the administration of donepezil (Aricept)?
A. Parkinson's disease
B. Bladde