Flashcards in Pharm 4 Lecture Deck (21):
What is the site of action of ganglionic blockers?
Nicotinic receptors at the ganglia
Names for Anticholinergics
3 Categories of of Anticholinergics
2. Ganglionic Blockers
3. Neuromuscular Blockers
Neuromuscular Blockers: Non-Depolarizing
Act as antagonists
All are given IV but vary in 1/2 life, length, metabolism and propensity to cause histamine release
Neuromuscular Blockers: Depolarizing
Act as agonists
Typical adult dose: 0.4-1.0 mg
For bradycardia, repeat q3-5 min up to 3x
Typical adult dose
How do we use antimuscarinics?
Patients with advanced heart disease often have increased parasympathetic tone
Adjunct Parkinson's Disease Therapy
Excessive GI hypermotility (Lomotil)
urinary urge incontinence
What are the side effects of antimuscarinics?
Hot dry skin
tachycardia (knocking out vagus nerve)
sedation/stasis of urine
What are the uses for ganglionic blockers?
Hypertensive crises, dissecting aortic aneurysms, reduce bleeding during neurosurgery
Ganglionic Blocker Side Effects
Profound hypotension via loss of sympathetic tone
Negative ionotrope (no reflex tachy)
short duration of action (5-15 minutes)
Typical adult dose:
1.0-3.0 mg bolus
What is neuromuscular blocker agent used for?
Extensively in surgery to prevent patient movement
Does not sedate, tranquilize, or anesthetize the patient
Tubocurare developed clinically (paralyze diaphragm)
What are nondepolarizing neuromuscular blockers antagonized by?
What are nondepolarizing neuromuscular blockers synergistic with?
Halogenated hydrocarbon gas anesthetics
Aminoglycoside antibiotics (amikacin, gentamycin)- inhibit ACh release
Very short-acting (shorter duration of action than any nondepolarizing agent (<8min) so useful in intubation
Broken down by pseudocholinesterase when circulating in the plasma (but not AChE at the NMJ)
Must diffuse away from the NMJ to be metabolized and allow ACh back into its receptors