Ganglionic blockers Flashcards
ganglionic blockers
reduce the most prominent autonomic tone in each organ
-these agents have no major clinical uses
hexamethonium (C6)
- was the first effective anti-hypertensive but had problems of poor absorption and side effects.
- prevents baroreceptor reflex
mecamylamine
- improves GI absorption
- recent interest in Tourettes
What to these do in the arterioles
vasodilation, hypotension
what do these do in the veins
dilation
what do these do in the ciliary muscle
cycloplegia
what do these do in the sweat glands
anhidrosis
what do these do in the bladder
urinary retention
Salivary gland predominant tone
Parasympathetic; effect of ganglionic blockade is xerostomia (dry mouth)
nicotine toxicity
GI (nausea, vomiting, salivation, diarrhea); CV (tachycardia and hypertension OR bradycardia and hypotention); CNS (lethargy, confusion, seizures, coma); PNS (diaphoresis, weakness, tremors, fasciculation, paralysis); ENDO (increased catecholamine release)
depolarizing ganglionic blocker: nicotine
Initial activation of ganglionic nAChRs followed by receptor blockade from persistent depolarization; leading to Na channel inactivation
Pharmacological effects of nicotine
Stimulation of autonomic ganglia followed by ganglionic blockade (predominant tone/dose dependent); stimulation of adrenal medulla (secretion of epinephrine); CNS stimulation (alerting, change in respiration); may stimulate the chemoreceptor trigger zone (vomiting); may stimulate muscles (excitation then weakness)
