PHARM SHIT YOU NEED TO KNOW Flashcards
What NT does the somatic nerv sys use? And what is the effector organ?
AcH; skeletal muscle (motor)
What are the NTs for sympathetic inn to the smooth muscles, cardiac cells, and gland cells? Include pre-/postganglionic.
preganglionic = Ach postganglionic = NE
What are the NTs for sympathetic inn to the sweat glands? Include pre-/postganglionic.
preganglionic = Ach postganglionic = Ach
What are the NTs for sympathetic inn to the adrenal gland’s medulla ganglion? Include pre-/postganglionic.
preganglionic = Ach postganglionic = cells of the medulla which secrete epi/NE
What are examples of neurohormones?
vasopressin (ADH) & oxytocin
What effect does NE have on the heart? On the brain? On the eyes? In the intestine?
heart - inc HR, force, BP
brain - inc signals (inc alertness)
eyes - dilates pupil
intestine - inc sphincter tone (contracts) & relaxes mm–can cause constipation
*recall that NE is released during postgang sympathetics (w/ the exception of sweat glands & adrenal medulla)
what types of fibers/nerves are cholinergic?
- pregang fibers of both sympathetic & parasympathetic nerv sys
- postgang PS fibers
- post gang sympathetic n for sweat gland
- pregang sympathetic fibers to adrenal gland
- somatic nn
What are some excitatory NTs?
dopamine, NE, epi, glutamate, acetylcholine
What are some inhibitory NTs?
serotonin, glycine, GABA, anandamide (this last one could also have excitatory effects–not sure yet)
What is anandamide?
endogenous cpd similar to marijuana that has anti-anxiety effects and related to bliss or delight
What are the events occurring during an erection involving NO and NE?
NE is released in blood vessels all the time, but when NO is released during erection, its effect overpower the vasoconstriction caused by NE until ejaculation. Then the NE overpowers the NO lowering the blood flow.
What does NO do?
opposes the excitatory actions of blood vessels (vasodilation, inc blood flow); in smooth muscle it will cause hypotension
What molecule does NO activate during an erection?
activates soluble guanylate cyclase
what does guanylate cyclase do?
synthesizes cGMP from GTP
_____ is believed to be the main vasoactive nonadrenergic, noncholinergic neurotransmitter and chemical mediator of penile erection
Nitric oxide (NO)
Acting as a second messenger molecule, ____ regulates the activity of calcium channels as well as intracellular contractile proteins that affect the relaxation of corpus cavernosum smooth muscle
cGMP
What is released from terminals of specific sensory neurons and associated w/ inflamm and pain?
Substance P!
- it coexists w/ excitatory NT glutamate in primary afferents that respond to painful stimul.
- may be involved in neurogenic inflamm
calcitonin gene related peptides function?
potent vasodilator and can function in the transmission of pain. When CGRP is derived from DRG when synthesized in the dorsal horn of the spinal cord, it may be linked to transmission of pain.
what types of fibers/nerves are adrenergic?
postgang fibers of sympathetic sys (except for those innervating sweat glands–cholinergic nn)
*also adrenal medulla are modified sympathetic neurons that release epi/NE
what types of fibers/nerves are nitrergic?
postgang fibers innervating sex organs, some postgang fibers in intestine & lower esophageal sphincter
What enzyme converts NE to epi?
PNMT = phenylethanolamine N-methyltransferase
Metyrosine is used to treat what disease?
pheochromocytoma (tumor of adrenal gland)–secrete high amts of catecholamines
what is the rate limiting step of NE synthesis?
tyrosine hydroxylase step; used in tx for pheochromacytoma (drug: Metyrosine)
Issues w/ DOPA decarboxylase results in…? What is the tx for this?
degeneration of neurons in brain that release DOPA; L-DOPA or carbidopa
What is carbidopa used for?
Tx for Parkinson’s; used in adjunct w/ L-DOPA
- carbidopa does NOT cross the blood-brain barrier, so it works in the periphery (reduces metabolism of L-DOPA in periphery)
- L-DOPA is in the periphery, but is not blocked completely in the brain–so it is more available there, if we reduced its metabolism in the periphery.
What is the main goal of the tx for parkinson’s?
inc production of dopamine!
- this is done by increasing levels of DOPA by using L-DOPA & carbidopa.
- reduce DOPA metabolism in the periphery (you want more of it in the brain!)
Disulfiram is used to treat what?
alcoholism; inhibits actylaldehyde dehydrogenase; disulfiram chelates w/ Cu in dopamine-B-hydroxylase (enzyme that converts dopamine to NE), inhibiting it!
- you will accumulate acetylaldehyde if you use this drug… so if you drink and take this drug, you may get hypertension!!
What is reserpine? Tx for?
- an inhibitor of DA & NE uptake into synaptic vesicles (blocks VMAT)
- inhibits NE production bc blocked entry of dopamine into the vesicle
- also no storage of NE (depletes NE from nn)
- tx for hypertension & psychosis; to reduce agitation in horses
- does NOT interfere w/ uptake from nerve memb–only the vesicles!!
What is reserpine’s effect in the brain?
depletes dopamine, NE, serotonin
*when they began to use reserpine to treat hypertension & psychosis, pts began to show suicidal tendencies.
What does the PSNS do to the GI system?
promotes peristalsis and gut motility
What nerv system causes GI cramps & diarrhea?
dec in NE (dec in SNS); inc in PSNS
what converts a-methyldopa to a-methyldopamine?
dopadecarboxylase
what converts a-methyldopamine to a-methylnorepinephrine?
dopamine-B-hydroxylase
What is a-methyldopa (aldornet) used for?
pregnancy induced hypertension (preecalampsia)
a-methylNE is taken up by the nerves and…?
displaces NE (“false NT” bc it is not an endogenous substance but stored and acts like NE); activates alpha-2-receptors and reduces the flow of impulses from the brain
- it dec sympathetic activity > leads to dec in flow of impulses > dec NE release
MAIN PT: a-MNE lowers BP
What is Bretylium Tosylate?
an IV or IM injection that inhibits NE release and is used in intensive care or coronary care units for life threatening ventricular arrhythmias.
How does Bretylium Tosylate work?
- It increases ventricular fibrillation threshold.
- produces initial transient inc followed by inhibition of NE release
- increases action potential duration & effective refractory period
- it basically dec the output of the SNS in the periphery
What happens when you take cocaine in the body?
- cocaine blocks the reuptake of NE at varicosity memb
- NE will accumulate = more energetic, higher BP/HR/etc
- in the brain - also inhibits uptake of dopamine & serotonin
which agent will not be able to alter blood pressure after taking cocaine?
amphetamine
*must know that this occurs when you take cocaine before MAO or amphetamine due to the transport pump being blocked.
how can cocaine cause a cardiac arrest?
blocks Na conduction in the heart due to its local anesthetic effect
The amine pump on the varicosity memb can take up what substances?
NE, epi, DA, & indirect sympathetic amines (amphetamine, tyramine)
What is the diff betw the 2 indirect sympathetic amines?
Tyramine is metabolized by MAO in the GI tract, but
amphetamine is not.
*if you take an inhibitor of MAO, you will inc tyramine and thus inc NE release from nerves.
What is the main action of amphetamine and tyramine?
They get into the nerve and pumps NE out of the nn. Indirectly, cause inc in HR, BP, etc.
What metabolizes extraneuronal uptake of catecholamines? What inhibits this?
metabolized by MAO & COMT; inhibited by corticosterone
What drugs block neuronal uptake of NE into nn?
cocaine, tricyclic antidepressants (desipramine)
What is desipramine used for?
tx of depression & migraine headache
Only therapeutic use of cocaine is?
- Diagnosis of Horners Syndrome, where a pt has uneven size of pupils and drooping eyes due to dmg to pre/postgang sympathetic neurons.
- need a release of NE to get an effect from cocaine, so you give these pts cocaine… if there is dilation, means cocaine worked. if there is no dilation, Horner’s syndrome–lack of NE.
if you give amphetamine to a pt w/ horner’s syndrome and it does not work, this means there is…?
postganglionic dmg (recall that amphetamine is taken up by amine pump and releases NE)
What are the major urinary metabolites of EPI & NE?
VMA, MHPG, MOPEG, normetanephrine (from NE), and metanephrine (from epi)
What are the major urinary metabolites of dopamine?
Homovanillic acid (HVA) and dihydroxyphenylacetic aicd (DOPAC)
*Ex. which of the following is not a metabolite of NE? answer could be HVA
Important MAO-A and B inhibitor? What are they used for?
phenelzine (Nardil); used for tx of depression and panic disorders
Important MAO-B inhibitor? What are they used for?
Selegiline; used to treat depression, dementia, early stages of parkinson’s (with or without L-DOPA)
What is entacapone, and what is it used for?
a COMT inhibitor; in adjunct w/ DOPA for Parkinson’s
- it does not cross the blood brain barrier!!
- it blocks the enzyme that metabolizes L-DOPA (DOPA decarboxylase, COMT) from the brain
What 3 drugs in adjunct w/ L-DOPA can be used to treat parkinson’s?
Selegiline, entacapone, carbidopa
What does atropine do?
selectively blocks the activity of ACH (blocks nicotinic receptors)
What type of adrenergic receptors are in the blood vessels? Activation of them causes what?
a1 & a2 - vasoconstriction
B2 - dilation or relaxation
What adrenergic receptors does NE activate?
only a1, a2, B1
*NE doesn’t stimulate B2 anywhere.
In the heart, there is primarily what type of adrenergic receptor? Stimulating it causes what?
B1; increases HR–coronotrophic effect, and increases contractility or ionotrophic effect.
What adrenergic receptors does epi activate?
all of the diff types: a1/a2/B1/B2/B3
Direct-acting a1 adrenergic agents? (Include agonists, distribution & responses, and adrenergic receptors.)
Epi (a1, a2, B1, B2)
NE (a1, a2, B1) [Levarterenol]
Phenylephrine (a1) [Neo-synephrine]
vasoconstriction in blood vessels, contraction of radial muscle in the eyes, decrease tone & motility (GIT), contraction of sphincter m. (GIT & bladder)
Direct-acting a2 adrenergic agents? (Include agonists, distribution & responses, and adrenergic receptors.)
Epi (a1, a2, B1, B2)
NE (a1, a2, B1) [Levarterenol]
Clonidine [Catapress]
vasoconstriction in blood vessels, platelet aggregation, decrease tone & motility (GIT), hypotension (RVLM)
*dec sympathetic outflow to the heart and BVs
What does clonidine do?
- initially it will inc the BP via vasoconstriction, but once it reaches the brain, it reduces the BF (vasodilation).
What effect does clonidine have in the brain?
- causes inhibitory effects/reduces the flow of impulses in the RVLM.
So when asked what alpha-2 adrenergic agonist lowers blood pressure…?
Clonidine
Direct-acting B1 adrenergic agents? (Include agonists, distribution & responses, and adrenergic receptors.)
Epi (a1, a2, B1, B2)
NE (a1, a2, B1) [Levarterenol]
Isoproterenol (B1, B2)
Dobutamine (higher doses: a1, B1, B2) [Dobutrex]
cardiac stimulation (heart), FA mobilization (adipose tissue), dec tone and motility (GIT), inc in renin release (kidney)
What type of adrenergic receptors are in fatty tissue?
B1
Direct-acting B2 adrenergic agents? (Include agonists, distribution & responses, and adrenergic receptors.)
Short Duration:
- Epi (a1, a2, B1, B2)
- Isoproterenol (B1, B2)
- Terbutaline [Brethin]
- Albuterol [Proventil]
Long Duration:
- Salmeterol [Serevent]
- Formoterol [Foradil]
- Indacaterol [Arcapta Neohaler] (24 hour)
Dilation of aa & vv, relaxation of GIT smooth muscle, relaxation of bronchial smooth muscle, inc insulin secretion, relaxation (pregnant) (uterus)
What type of tissue has the highest density of B2 receptors?
Bronchial Smooth Muscle!
What will happen if you block B2 receptors?
inc airway resistance and vascular resisitance
What will happen if you block B1 receptors?
dec in HR, force, and renin production
In the heart, activation of B1 receptors lead to ….?
increases in contractile force & HR
Activation of the beta2 receptor leads to …?
vascular and nonvascular smooth muscle relaxation
Alpha2 receptors also exist presynaptically associated with nerve terminals. Activation of these receptors cause… ?
inhibition of the release of NE.
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*NE acts at presynaptic alpha2 receptors to inhibit its own release
Associated with vascular smooth muscle are a large number of alpha1 receptors relative to beta2 receptors. Activation of these receptors by sympathetic nervous system transmission or drugs will result in …?
vasoconstriction and an increase in peripheral resistance and systemic arterial blood pressure.
What would happen if we blocked alpha receptors?
vasodilation; used for tx of hypertension
What are the effects when stimulating postjunctional dopaminergic receptors (D1 receptors)?
- vascular relaxation (renal & mesenteric blood vessels)
- natriuresis & diuresis (kidney)
- stimulation of PTH release (parathyroid gland)
*these drugs are used for shock