Muscarinic and nicotinic blockers Flashcards
Nicotinic receptor agonists. Examples
Nicotine
Acetylcholine
Choline
Epibatidine
Lobeline
Varenicline
Cytisine
Natural nicotinic agonists (selective)
Nicotine(small doses)
Lobeline
Synthetic Nicotinic Agonists (selective)
Dimethyl phenyl piperazinium (DMPP)
Tetra methyl ammonium (TMA)
Excessive amounts of selective nicotinic agonists leads to
Sustained depolarization
Ganglion block
Non-selective muscarinic agonists
ACh
Pilocarpine
Carbachol
Anti-ChE
Nicotine is what type of amine and is derived from
Tertiary
Nicotiana tobacum leaves
Overall effects of GANGLIONIC stimulation on Blood vessels (sympathetic)
Vasoconstriction
Hypertension
Reduced peripheral blood flow
Effects of Ganglionic stimulation in the heart, GIT, Eye, UT, salivary gland
Same as Parasympathetic
Bradycardia, Increased tone, Miosis, Urination, watery salivation
Effect of ganglionic stimulation on sweat gland
Increased sweating (sympathetic)
Nicotine is available as transdermal patches for
Treating nicotine dependence
Varenicline :
Partial agonist
Reduces craving for and pleasurable effects of cigarettes
Vesamicol
Inhibits ACh carrier (Vesamicol inhibits acetylcholine uptake in presynaptic vesicles and reduce its release)
Botulinum
Presynaptic toxin that inhibits exocytosis of ACh from vesicles
Tubocurarine
Non-Depolarizing blocking agent(at synapse). Competitive antagonist of ACh
Suxamethonium
Depolarizing blocking agent. Inhibits the Post synaptic ACh receptor
Neostigmine
Anticholinesterase (inhibits AChE enzyme)
Hemicholinium
Inhibits the reuptake of choline (inhibits the choline carrier)
Action on M1 receptor on gastric gland
Histamine release
Acid secretion
Clinically Selective Anticholinergic Drugs (M1)
Pirenzepine
Telenzepine
Dicyclomine
Trihexyphenidyl
Function of M2 receptor on atrium
Shortening of APD, reduced contractility
Function of M2 receptor and on the CNS
tremor, anelgesia
Clinically selective anticholinergic drugs (M2)
Tripitamine, Methoctramine
Effects of M3 on visceral smooth muscle
Contraction
Effects of M3 on vascular endothelium
Release of NO to produce vasodilation
Clinically Selective Anticholinergic drugs (M3)
Darifenacin
Solifenacin
Oxybutinin
Tolterodine
When activated, M4 receptors inhibit ACh release in the …………….
Striatum
Antagonist drug of M4 receptors
Himbacine
List the natural anti muscarinic drugs
- Atropine (DL-hyoscyamine)
- Scopolamine (L-hyoscine)
Synthetic anti muscarinic drugs are divided into
Structural analogues of atropine
Structurally non related to atropine
List the tertiary ammonium compounds that are structural analogues of atropine
Homatropine
List the anti muscarinic drugs that are quarternary ammonium compounds
- Atropine methyl nitrate (Amn)
- Homatropine methyl bromide (Hmb)
- Methscopolamine bromide (Mb)
- Ipratropium
- Tiotropium
List the Tertiary amines structurally unrelated to atropine (anti muscarinic)
- Pirenzepine
- Dicyclomine
- Cyclopentolate
- Oxyphancyclimine
- Tropicamide