Autonomic Pharm Flashcards
In the sympathetic division of the ANS the pre-ganglionic fibers are _______ while the post ganglionic fibers are ________.
short pre-ganglionic
long post-ganglionic
In the parasympathetic division of the ANS the pre-ganglionic fibers are _______ while the post ganglionic fibers are ________.
long pre-ganglionic fibers
short post-ganglionic fibers
In the parasympathetic division, what do post ganglionic fibers release and onto what type of receptors?
ACH to muscarinic receptors at the effector organ
In the sympathetic division, what do post ganglionic fibers release and onto what type of receptors?
NE to alpha or beta adrenergic receptors
The first synapse regardless of the autonomic division is ____________ and is associated with what NT?
cholinergic
Ach
What is the MOA of direct acting cholinergic agonists?
act at the ACH receptor = longer duration of action
What is the MOA of indirect acting cholinergic agonists?
cholinesterase inhibitors
cause release of ACH = Ach accumulation by stopping breakdown of Ach
Where are nicotinic receptors located?
striated muscle
N1/Nm = neuromuscular junction
N2/Nn = autonomic ganglia, CNA, adrenal medulla
Where are muscarinic receptors located?
effector organ
What are the side effects of cholinergic drugs?
S= salivation L= lacrimation U= urination D= defaction
Indirect acting cholinergic drugs can be used for what types of tx?
glaucoma myasthenia gravis post-op urinary retention antidote to poisons GI disorders, paralytic illeus (inc. motility)
What are the pharmacological effects produced by cholinergic drugs?
- bradycardia
- decreased BP and cardiac output
- Miosis
- Decreases intraocular pressure
- Increases GI motility
What are 2 cholinergic agents used in dentistry and what do they do?
pilocarpine (Salagen)
cevimeline (Evaoxac)
fxn: increase salivary secretion
What is the MOA of indirect acting cholinesterase inhibitors?
Stop the breakdown of acetylcholine (via cholinesterase), which allows for the concentration of acetylcholine to build up = acetylcholine remains active and stimulates the PANS
What do reversible cholinesterase inhibitors do?
increase ACH
Centrally acting acetylcholinesterase inhibitors are used for what types of tx?
tx dementia with Alzheimer’s disease & investigational for mild to mod dementia with Parkinson’s disease
What is bad about irreversible cholinesterase inhibitors?
they increase ACH too much!
= poisons, nerve gases, chemical warfare, insecticides etc.
What are 2 agents that can be used to reverse the effects of organophosphate (insecticide) poisoning?
pralidoxime (2-PAM, Protapam)
atropine (antimuscarinic)
What is the MOA of Pralidoxime?
regenerates the irreversibly bound ACH receptor sites that are bound by the inhibitors
What is the MOA of atropine?
competitively blocks muscarinic effects of excess ACH
What is the MOA of anticholinergic drugs?
prevents ACH action at postganglionic PANS nerve ending blocks receptor site for ACH → ACH cannot act on smooth m, glands, heart
reduce PANS activity
T/F the CNS effects form anticholinergic drugs depends on the dose
True
What anticholinergic drug is used in the tx for motion sickness?
Scopolamine
What is the effect of anticholinergic drugs on exocrine glands?
dries up secretions
reduces flow/volume
What is the effect of anticholinergic drugs on smooth muscle?
respiratory bronchiodilation
GI antispasmodics
GU urine retention
What type of drug would you use for overactive bladder tx?
anticholinergic
What type of drug is used for tx of peptic ulcer disease and IBS?
anticholinergics
Why are anticholinergics given during an eye exam?
They cause mydriasis (dilation)
How are anticholinergics used in surgery?
used to prevent bradycardia during general anesthesia (can cause vagal blockade resulting in tachycardia in large doses)
What is the effect of anticholinergic drugs on the eye?
mydriasis
cycloplegia
What is the effect of anticholinergic drugs on skeletal muscle?
reduce tremor and muscle rigidity (Parkinson’s tx)
What anticholinergic drug is commonly used in dentistry and why?
Atropine: used to decrease salivary flow and crease dry filed for bonded restoration and impressions in mouth and airway
What are the indications of atropine toxicity?
Dry as a bone (lack of sweating)
Red as a beet (flushed skin)
Blind as a bat (blurred vision; mydriasis and cycloplegia)
Mad as a hatter (delirium, hallucinations)
What are the 3 neuromuscular blocking agents?
- tubocurarine (Curare)
- succinylcholine
- Botulinum toxin (botox)
What does tubocurarine (Curare) do?
skeletal m. relaxant
What does succinylcholine do and what is it used for?
Causes flaccid paralysis
Used for endotracheal intubation
What does Botox do?
produces state of denervation
Prevents calcium- dependent release of ACH
What are the indications for botulinum toxin?
muscle tics, muscle disorders, cosmetic procedures
What are the 3 endogenous catecholamines and where do they come from?
Epinephrine: adrenal medulla
Norepinephrine: terminal nerve endings
Dopamine: brain, splanchnic, renal vasculature
What do B1 receptors do in response to sympathetic stimulation?
increase HR and contractility
breakdown glycogen
What do B2 receptors do in response to sympathetic stimulation?
smooth m. relaxation
vasodilation
bronchiodilation
What do alpha agonists cause?
vasoconstriction of vessels
pale pallor
smooth muscle contraction
What do alpha antagonists cause?
block vasoconstriction
decrease TPR and BP
reverse dilation of pupils
What do beta antagonists cause?
decrease HR, contractility, cardiac output, conduction velocity
decrease cardiac oxygen demand
reduce intraocular pressure
What type of cholinergic agent would you use to tx Sjogrens? Give examples.
Direct cholinergic agent:
cevimeline (Evoxac)
pilocarpine (Salagen)
What are the clinical uses for adrenergic agonists?
vasoconstriction decongestants Tx for shock - elevate low bp Tx for cardiac arrest (Epi) Asthma and emphysema CNS stimulation - amphetamines to tx ADD/ADHD
What are the tx indications for alpha blockers?
- second line agents for hypertension Raynaud's syndrome benign prostatic hypertrophy pheochromyocytoma peripheral vascular disease
Differentiate between selective and non-selective Beta blockers
Selective: B1
Non selective: B1 & B2
How do you distinguish between selective and non-selective based off of the name only?
First letter:
A to M = selective
N to Z = non-selective
What are selective Beta blockers used for?
pt has diabetes or respiratory issues (atenolol, metoprolol)
What is the beta 2 agonist included in dental office emergency kits and its indication for use?
Albuterol - bronchodilator
What is the dose for epinephrine in dental anesthetics that is given to patients with heart disease?
0.04 mg of epinephrine (2 cartridges of epinephrine 1:1000,000)
What are the effects of epinephrine on heart rate and blood pressure if given to a patient taking a selective versus a non-selective beta blocker?
2-4 fold increase in the pressor response to epinephrine =
Hypertension (increases risk for MI and stroke)
Reflex bradycardia
