Transcript 11-muscarinic & ganglionic blockers

Muscarinic antagonists:Naturally occurring atropine & hyoscine,
homatropine
Quaternary
ammonium
comp:atropine
methonitrate,
propantheline.
Pirenzepine,
selective M1
receptor
antagonist
Pharmacokinetic aspects:hyoscine absorbed transdermally.
4º amines do not cross the BBB
Metabolism & excretion:-
Mechanism:reversible
blockade of
Ach at
muscarinic
receptors.
Organ system
effects:CNS:- atropine at
clinical dose, initial
stimulation followed by
slower longer –lasting
sedative effect ,
Hyoscine sedative
effect
2-Eye:- pupillae
constrictor mydriasis,
cilliary muscle
[cycloplagia].
3- lachrymal secretion.
3-Cardiovascular system:SA node & atrium.
Atropine on isolated heart  tachycardia ,
Intact animals, initial bradycardia followed
by tachycardia
Skeletal muscle blood vessels →
↓vasodilatation .
4-Respiratory system:Atropine bronchodilation
& of secretion
5-GIT:-motility
&secretion.
salivary glands,
gastric secretion.
Pancreatic & intestinal
secretion.
6-Genitourinary
tract:uriters, bladder wall,
7-Sweat glands:in children modest
doses ”atropine
fever”
Quiz?
Your pharmacology laboratory has
been given a new compound for
screening. It is found to increase
heart rate, dilate the pupil, reduce
glandular secretions and decrease
gastrointestinal motility. You would
classify this compound as a(an):1. alpha agonist
2. antimuscarinic
3. beta agonist
4. parasympathomimetic.
A-CNS:- aParkinsonism:benzhexol,
benztropine
b-Motion
sickness:hyoscine
B-Ophthalmic
disorders:ophthalmoscope
examination of
retina
Quiz?
Mydriasis without loss
of accommodation:atropine
sympathomimetic
Scopolamine
Tropicamide
cyclopentolate
C-GIT:i- gastric hypermotility & ulcer.
Pirenzepine
ii-Facilitate endoscopy
iii-Irritable bowel
syndrome, colonic
diverticular disease
e.g. dicyclomine
iv-Traveler's
diarrhoea with
opioid
[diphenoxylate]
v-biliary & renal
colic.
urinary urgency caused by minor
inflammatory bladder disorders
E-Cardiovascula effects:pain of myocardial infarction] depression
of SA, AV node
[sinus bradycardia ]
F-Respiratory disorders:pre- operative medication when
anaestheticsecretion &
laryngospasm,
Hyoscine amnesia,
Ipratropium,
inhalation ,
bronchial asthma,
chronic obstructive
pulmonary disease
(COPD)
Hyperhydrosis
F-Cholinergic
poisoning:Cholinesterase
inhibitors
“insecticides”.
Mushroom
poisoning.
Quiz?
Current primary therapeutic
rationale for using
anticholinergic preoperative
medication:sedation
antisialagogue effects
both
neither
Quiz?
Preferred anticholinergic
drug when sedation is the
principal objective,
preoperatively:atropine
glycopyrrolate
hyoscine
Quiz?
Anticholinergic drug most
likely to be used clinically to
promote bronchodilation:IV atropine
aerosolized atropine
aerosolized ipratropium
bromide
scopolamine
Dry mouth ,
mydriasis,
tachycardia ,
hot flushed skin,
agitation,
delirium,
 body temperature,
blurred vision ,
confusion ,
constipation,
urinary retention .
Reversed by physostigmine .
Quaternary amine poisoning is reversed
by quaternary CI,
hypotension reversed by
sympathomimetic drugs
Contra- indications:Glaucoma,
elderly people with prostatic hypertrophy
tachycardias secondary to
thyrotoxicosis or cardiac insufficiency,
GI obstructive disease,
paralytic ileus,
Non selective M blockers →ulcer
Quiz?
Which of the following is not
a side effect of the
cholinoreceptor blocker
(Atropine)?
A. Increased pulse
B. Urinary retention
C. Bronchospasm
D. Mydriasis
Quiz?
A patient is brought into the emergency room. Upon
examination you find the following: a high fever,
rapid pulse, no bowel sounds and dilated pupils that
do not respond to light. His lungs are clear. His face
is flushed and his skin is dry. He is confused,
disorientated and reports 'seeing monsters'. Based
on these symptoms, you suspect he has been
'poisoned'. Which of the following, is the MOST
obvious and BEST choice as an antidote?
A. Atropine sulfate
B. Physostigmine
C. Neostigimine
D. Acetylcholine
Quiz?
You are working in the post anesthesia care unit
of a hospital. You have just received a patient
back from surgery and you are monitoring his
status. Knowing that the patient has received
atropine, which of the following
statements/observations is UNEXPECTED?
A. The patient is complaining of extreme thirst.
B. The patient complains he is unable to clearly see
the clock located just across from him.
C. The patient's heart rate is elevated.
D. The patient reports he has cramping and diarrhea.
A 55-year-old man was found unconscious
by his wife in the greenhouse behind their
home. During the past week, he had been
complaining of abdominal discomfort and
frequent stools. He had no history of mental
illness or of alcohol or tobacco use, and he
was not taking any medication. He and his
wife operated a small flower shop, and he
was an enthusiastic home gardener. Upon
arrival at the emergency room, the patient
was unconscious, salivating profusely, and
breathing shallowly. His skin was warm and
moist. Blood pressure was 140/90 mm Hg,
pulse 72/min and regular, respirations
30/min, and temperature normal.
There was no evidence of trauma. Both
pupils were constricted and did not
respond to light. Auscultation of the chest
revealed moderate wheezing. The
extremities showed subcutaneous
muscle fasciculations at the time of
admission. These disappeared during
the course of the examination, but
muscle tone decreased and breathing
became shallower during this time. The
neurologic examination revealed coma
with no response to painful stimuli, no
localizing signs, and no abnormal
reflexes.
Q1
What are the possible
toxicologic causes of the
patient's signs and
symptoms?
Q2?
What immediate
nonpharmacologic steps
must be taken?
Q3?
What drugs may be
considered for the
treatment of this patient?
What are the risks and
benefits of their use?