Flashcards in AGENTS, CONTROLLING THE FUNCTIONS OF THE PERIPHERAL NERVOUS SYSTEM - Cholinoreceptor blocking drugs Deck (78):
The group of nicotinic receptor-blocking drugs consists of
- Neuromuscular junction blockers
M3 receptor subtype is located
On effector cell membranes of glandular and smooth muscle cells
Which drugs is both a muscarinic and nicotinic blocker?
Indicate a muscarinic receptor-blocking drug
Which agents is a ganglion-blocking drug?
Indicate the skeletal muscle relaxant, which is a depolarizing agent
Which drugs is a nondepolarizing muscle relaxant?
Indicate the drug, which is rapidly and fully distributed into CNS and has a greater effect than most other antimuscarinic agents?
The effect of the drug on parasympathetic function declines rapidly in
- Smooth muscle organs
The effect of the drug on parasympathetic function declines rapidly in all organs EXCEPT
The mechanism of atropine action is
Competitive muscarinic blockade
The tissues most sensitive to atropine are
The salivary, bronchial and sweat glands
Atropine is highly selective for
- M1 receptor subtype
- M2 receptor subtype
- M3 receptor subtype
Which antimuscarinic drugs is often effective in preventing or reversing vestibular disturbances, especially motion sickness?
Mydriasis, a rise in intraocular pressure and cyclo
Patients complain of dry or “sandy” eyes when receiving large doses of
All of the following parts of the heart are very sensitive to muscarinic receptor blockade
- Sinoatrial node
- Atrioventricular node
All of the following parts of the heart are very sensitive to muscarinic receptor blockade except:
Tachycardia, little effect on blood pressure and bronchodilation
Atropine is frequently used prior to administration of inhalant anesthetics to reduce
Atropine is now rarely used for the treatment of peptic ulcer because of
- Slow gastric empting and prolongation of the exposure of the ulcer bed to acid
- Low efficiency and necessity of large doses
- Adverse effects
Which antimuscarinic drugs is a selective M1 blocker?
Which drugs is useful in the treatment of uterine spasms?
Atropine may cause a rise in body temperature (atropine fever)
In infants and children
The pharmacologic actions of scopolamine most closely resemble those of
Compared with atropine, scopolamine has all of the following properties
- More marked central effect
- More potent in producing mydriasis and cycloplegia
- Lower effects on the heart, bronchial muscle and intestines
Compared with atropine, scopolamine has all of the following properties EXCEPT
Less potent in decreasing bronchial, salivary and sweat gland secretion
Which drugs is useful in the treatment of Parkinson′s disease?
Indicate the antimuscarinic drug, which is used as a mydriatic
Which agents is used as an inhalation drug in asthma?
Which agents is most effective in regenerating cholinesterase associated with skeletal muscle neuromuscular junctions?
Indicate an antimuscarinic drug, which is effective in the treatment of mushroom poising
Antimuscarinics are used in the treatment of
- Motion sickness
Antimuscarinics are used in the treatment of the following disorders EXCEPT
The atropine poisoning includes all of the following symptoms EXCEPT
Bradicardia, orthostatic hypotension
The atropine poisoning includes all of the following symptoms
- Mydriasis, cycloplegia
- Hyperthermia, dry mouth, hot and flushed skin
- Agitation and delirium
The treatment of the antimuscarinic effects can be carried out with
Contraindications to the use of antimuscarinic drugs are
- Paralytic ileus and atony of the urinary bladder
Contraindications to the use of antimuscarinic drugs are all of the following except
Hexamethonium blocks the action of acethylcholine and similar agonists at
The applications of the ganglion blockers have disappeared because of all of the following reasons EXCEPT
The applications of the ganglion blockers have disappeared because of all of the following reasons
- Orthostatic hypotension
- Lack of selectivity
- Homeostatic reflexes block
Which agents is a short-acting ganglion blocker?
Indicate the ganglion-blocking drug, which can be taken orally for the treatment of hypertension?
The systemic effects of hexamethonium include
- Reduction of both peripheral vascular resistance and venous return
- Partial mydriasis and loss of accommodation
- Constipation and urinary retention
The systemic effects of hexamethonium include all of the following EXCEPT
Stimulation of thermoregulatory sweating
Ganglion blocking drugs are used for the following emergencies
- Hypertensive crises
- Controlled hypotension
- Pulmonary edema
Ganglion blocking drugs are used for the following emergencies EXCEPT
Agents that produce neuromuscular blockade act by inhibiting:
Interaction of acetylcholine with cholinergic receptors
Skeletal muscle relaxation and paralysis can occur from interruption of functions at several sites, including
- Nicotinic acethylcholine receptors
- The motor end plate
- Contractile apparatus
Skeletal muscle relaxation and paralysis can occur from interruption of functions at several sites, including all of the following EXCEPT
Muscarinic acethylcholine receptors
Nondepolarisation neuromuscular blocking agents
Prevent access of the transmitter to its receptor and depolarization
Which drugs has “double-acetylcholine” structure?
Indicate the long-acting neuromuscular blocking agent
Which neuromuscular blocking drugs is an intermediate-duration muscle relaxant?
Indicate the nondepolarizing agent, which has the fastest onset of effect?
Indicate the neuromuscular blocker, whose breakdown product readily crosses the blood-brain barrier and may cause seizures
Which competitive neuromuscular blocking agent could be used in patients with renal failure?
Indicate the nondepolarizing agent, which has short duration of action
Which depolarizing agent has the extremely brief duration of action?
Neuromuscular blockade by both succinylcholine and mivacurium may be prolonged in patients wit
- An abnormal variant of plasma cholinesterase
- Hepatic disease
Depolarizing agents include
- React with the nicotinic receptor to open the channel and cause depolarisation of the end plate
- Cause desensitization, noncompetive block manifested by flaccid paralysis
- Cholinesterase inhibitors do not have the ability to reverse the blockade
Depolarizing agents include all of the following properties EXCEPT
Interact with nicotinic receptor to compete with acetylcholine without receptor activation
Which neuromuscular blockers causes transient muscle fasciculations?
Indicate muscles, which are more resistant to block and recover more rapidly
Which neuromuscular blocking agent has the potential to cause the greatest release of histamine?
Which of the following muscular relaxants causes hypotension and bronchospasm?
Indicate the neuromuscular blocker, which causes tachycardia
Which neuromuscular blocking agents cause cardiac arrhythmias?
Effects seen only with depolarizing blockade include
- Muscle pain
Effects seen only with depolarizing blockade include all of the following EXCEPT
A decrease in intraocular pressure
Which neuromuscular blocking agent is contraindicated in patients with glaucoma?
Indicate the following neuromuscular blocker, which would be contraindicated in patients with renal failure
All of the following drugs increase the effects of depolarizing neuromuscular blocking agents EXCEPT
Drugs that increase the effects of depolarizing neuromuscular blocking agents
- Antiarrhythmic drugs
- Local anesthetics
Which diseases can augment the neuromuscular blockade produced by nondepolarizing muscle relaxants?