Autonomic Pharmacology Flashcards
Describe the anatomic and functional organization of the Sympathetic division
Sympathetic: 1st neuron is SHORT, 2nd is longer
○ SHORT preganglionic fibers
○ ACH binds to nicotinic receptors & muscarinic receptors
○ LONG postganglionic fibers
○ NE binds to alpha or beta adrenergic receptors at effector organ
Describe the anatomic and functional organization of the Parasympathetic division
Parasympathetic: 1st neuron is LONGER, 2nd shorter
○ LONG preganglionic fibers ○ ACH binds to nicotinic receptors ○ SHORT postganglionic fibers ○ ACH binds to muscarinic receptors at effector organ ○ 2nd synapse is muscarinic
First synapse regardless of division (symp & parasymp) is ___________________.
Ach bind to _______________ receptors.
We block at the _______________ synapse where type of receptor varies.
- cholinergic
- nicotinic receptors
- second synapse
Adrenal Medulla:
- Innervated by ____________of the SANS.
- Stimulation causes ______________ and ____________.
- preganglionic fibers
- release of epinephrine and norepinephrine
Adrenal Medulla:
-The diffuse response of the SANS is produced because _______________ or ____________ results from systemic release of epinephrine & noreeponeprine and their effects on _____________ and ___________
- fight or flight response
- pre and post ganglionic fibers
How do drugs modify ANS activity?
1) Storage
2) Synthesis
3) Release
4) Receptor interaction
5) Dispostion (termination of neurotransmitter activity in synapse) = enzyme degradation or reuptake
Which 4 groups of drugs exert their effects on organs or tissues innovated by the ANS?
1) Parasympathetic (PANS) stimulatory
2) Parasympathetic (PANS) inhibitory (blocking)
3) Sympathetic (SANS) stimulatory
4) Sympathetic (SANS) inhibitory (blocking)
A drug that acts at the location where acetylcholine is released is termed _____________
cholinergic
A drug that acts at the location where norepinephrine is released is termed _____________
Adrenergic
A drug that acts at the location where the PANS acts has the prefix ______________
Parasympatho-
A drug that acts at the location where the SANS acts has the prefix ______________
Sympatho-
A drug that acts at the location where a division of the ANS acts & produces the SAME effect as the neurotransmitter has the suffix- ___________
-MIMETIC (AKA Agonist)
Acts the same as the neurotransmitter
A drug that acts at the location where a division of the ANS acts & blocks the action of the neurotransmitter has the suffix ______ or ______
- Lytic
- Blocker (AKA ANTAGONISTS)
Antagonists do not produce any drug effect: they ________ the receptor site (acting like a plug) to prevent the ______from producing the desired effect.
- block
- agonist
What are the STIMULATORY Parasympathetic (PANS) Drugs?
1) Cholinergics
2) Parasympathomimetics
What are the INHIBITORY Parasympathetic (PANS) Drugs?
1) Anticholinergics
2) Parasympatholytics
3) Cholinergic blockers
What are the STIMULATORY sympathetic (SANS) Drugs?
1) Adrenergics
2) Sympathomimetics
What are the INHIBITORY sympathetic (SANS) Drugs?
1) Adrenergic blockers
2) Sympathetic blockers
3) sympatholytics
What are 2 types of Cholinergic Agonists?
1) Direct acting:
- Agonists (Act at ACH receptor)
2) Indirect acting :
- Causes release of ACH (neurotransmitter)
- Cholinesterase inhibitors = cause accumulation of ACH = stimulating PANS
Describe direct acting Cholinergic Drugs
1) Act like acetylcholine (“Mimic” its effect) on receptors
2) Agonists
3) Longer duration of action
4) More selective in the effects produced
5) STIMULATE PANS
What is the receptor function ?
1) To be effective mediator, ACH must fit physically & chemically at receptor
2) there are differences among receptors that have ACH
3) Subtypes of ACH receptors are located in different synapses
What are examples of ACH receptors?
1) CNS (muscarinic & nicotinic)
2) Autonomic (muscarinic & nicotinic)
3) Neuromuscular (nicotinic)
What are other factors that account for differences in the response of the receptor to drugs at ACH-medicated junction receptors?
1) Amount of ACH release
2) Size of synaptic cleft
3) Tissue penetration of drug
What are the Pharmacologic effects of Cholinergic Drugs on the heart, eye & GI?
1) Cardiovascular:
- Bradycardia, decreased BP & CO
2) Eye:
- Produce miosis
- Decreases intraocular pressure
3) GI:
- Excites smooth muscle of gut
- Increase in activity, motility & secretion
What are the primary indication for use of direct acting cholinergic drugs?
1) Glaucoma
2) Myasthenia gravis (autoimmune disease)
3) DI disorders (INC GI motility)
4) Reverse urinary retention after surgery
What are examples of Direct Acting Cholinergic Agonists?
1) ACH (Miochol) -eye surgery
2) Bethanechol (Urecholine)- urinary retention
3) Carbachol (Miostat)-glaucoma
4) Cevimeline (Ecoxac) - Sjogren’s syndrome
5) Pilocarpine (Salagen)- glaucoma, Sjogren’s syndrome
Describe how pilocarpine (ophthalmic) works
1) Used in eye for glaucoma
2) Causes constriction allowing for drainage of fluid from eye thru canal of Schlem
3) Glacoma = increased intraocular pressure due to fluid. Can cause blinds if untreated.
4) Pilocarpine allows for DRAINAGE which DECREASES intraocular pressure
What is pilocarpine(Brand name: SALAGEN) used in dentistry for?
To stimulate SALIVARY SECRETIONS in patients w/ xerostomia
Another drug in this class of “pilocarpine” is _______________ , which is used for salivary stimulation in patients w/ Sjogren’s syndrome
-Cevimeline (Evoxac)
What are indirect-acting cholinergic drugs also known as and what do they do?
- Cholinesterase inhibitors
- They STOP the BREAKDOWN of ACH (via cholinesterase), which allows fro the concentration of acetylcholine to build up= ACH remains active
- They produce PANS stimulation
What are the primary indications for indirect-acting Cholinergic Agonists (Cholinesterase Inhibitors)
1) Myasthenia Gravis
2) Glaucoma
3) Postoperative urinary retention
4) Paralytic ileum (malfunction of nerves w/out blockage)
5) Antidotes to agents that produce non depolarizing neuromuscular blockage (poisons)
Indirect-Acting Cholinergic Drugs are divided into groups based on what?
The degree of reversibility with which they are bound to the enzyme
1) Reversible
- Also includes centrally acting drugs
2) Irreversible
How does Reversible Indirect-Acting Cholinergic Drugs affect ACH?
Increases it
Note: Causes skeletal muscle activation followed by blockage (prevent repolarization at motor end plate) = no muscle contraction