Autonomics

1.) Cholinergic refers to which division of the autonomic nervous system?

a) sympathetic

b) central nervous system

c) parasympathetic

d) peripheral nervous system

a) sympathetic

b) central nervous system

c) parasympathetic

d) peripheral nervous system

2.) Adrenergic refers to which division of the autonomic nervous system?

a) central nervous system

b) peripheral nervous system

c) parasympathetic

d) sympathetic

a) central nervous system

b) peripheral nervous system

c) parasympathetic

d) sympathetic

3.) Stimulation of the sympathetic and parasympathetic divisions cause opposite responses.

a) True

b) False

a) True

b) False

4.) Drugs that act as mediators of sympathetic transmission (cause a sympathetic response) are called

a) Parasympathomimetics

b) Sympathomimetics

c) Sympatholytics

d) Parasympatholytics

a) Parasympathomimetics

b) Sympathomimetics

c) Sympatholytics

d) Parasympatholytics

5.) Drugs that decrease sympathetic activity are called

a) Parasympathomimetics

b) Parasympatholytics

c) Sympatholytics

d) Sympathomimetics

a) Parasympathomimetics

b) Parasympatholytics

c) Sympatholytics

d) Sympathomimetics

6.) If your sympathetic nervous system is stimulated, what will you experience? (CHOOSE 4)

a) Increased saliva

b) Dilated pupils

c) Inhibited digestion

d) Slow heart rate

e) Low saliva

f) Constricted pupils

g) Stimulated digestion

h) Increased heart rate

a) Increased saliva

b) Dilated pupils

c) Inhibited digestion

d) Slow heart rate

e) Low saliva

f) Constricted pupils

g) Stimulated digestion

h) Increased heart rate

7.) If your parasympathetic nervous systen is stimulated, what will you experience?

a) Increased saliva

b) Dilated pupils

c) Inhibited digestion

d) Slow heart rate

e) Low saliva

f) Constricted pupils

g) Stimulated digestion

h) Increased heart rate

a) Increased saliva

b) Dilated pupils

c) Inhibited digestion

d) Slow heart rate

e) Low saliva

f) Constricted pupils

g) Stimulated digestion

h) Increased heart rate

8.) The two major types of receptors in the sympathetic system are:

a) nicotinic

b) alpha

c) beta

d) muscarinic

a) nicotinic

b) alpha

c) beta

d) muscarinic

9.) The two major types of receptors in the parasympathetic system are:

a) nicotinic

b) alpha

c) beta

d) muscarinic

a) nicotinic

b) alpha

c) beta

d) muscarinic

10.) Which neurotransmitter is released from all preganglionic neurons?

a) Acetylcholine

b) Norepinephrine

c) Dopamine

d) Serotonin

a) Acetylcholine

b) Norepinephrine

c) Dopamine

d) Serotonin

11.) Nerves that release norepinephrine are adrenergic.

a) True

b) False

a) True

b) False

12.) A drug that stimulates beta 1 receptors is called: (CHOOSE 2)

a) Sympathomimetic

b) Sympatholytic

c) Agonist

d) Antagonist

a) Sympathomimetic

b) Sympatholytic

c) Agonist

d) Antagonist

13.) An alpha 1 agonist can be used to treat:

a) Xerostomia

b) Hypertension

c) Nasal congestion

d) Asthma

a) Xerostomia

b) Hypertension

c) Nasal congestion

d) Asthma

14.) An alpha 2 agonist can be used to treat:

a) Xerostomia

b) Nasal congestion

c) Asthma

d) Hypertension

a) Xerostomia

b) Nasal congestion

c) Asthma

d) Hypertension

15.) Propranolol is a beta blocker that can be used to lower blood pressure in asthmatics.

a) True

b) False

a) True

b) False

16.) Atropine is a drug that is used to decrease saliva.

a) True

b) False

a) True

b) False

17.) Which of the following drugs is used in the treatment of xerostomia in dental patients?

a) atropine

b) acetylcholine

c) pilocarpine

d) nicotine

a) atropine

b) acetylcholine

c) pilocarpine

d) nicotine

18.) Which of the following drugs has an additive effect with anticholinergic drugs?

a) diphenhydramine (Benadryl)

b) aspirin

c) ibuprofen (Advil)

d) acetaminophen (Tylenol)

a) diphenhydramine (Benadryl)

b) aspirin

c) ibuprofen (Advil)

d) acetaminophen (Tylenol)

The parasympathetic division of the autonomic nervous system is also known as _____________. The primary neurotransmitter is _________________ which binds to ________________ receptors at the post ganglionic neuron and then to __________________ receptors at the effector muscle or target organ.

The parasympathetic division of the autonomic nervous system is also known as cholinergic. The primary neurotransmitter is acetylcholine (ACh) which binds to cholinergic/nicotinic receptors at the post ganglionic neuron and then to cholinergic/muscarinic receptors at the effector muscle or target organ.

The sympathetic division of the autonomic nervous system is also known as _____________. Acetylcholine binds to ________________ receptors at the post ganglionic neuron and then the primary neurotransmitter _________________ binds to ______ and ______ receptors at the effector muscle or target organ.

The sympathetic division of the autonomic nervous system is also known as adrenergic. Acetylcholine binds to cholinergic/nicotinic receptors at the post ganglionic neuron and then the primary neurotransmitter norepinephrine (NE) binds to alpha and beta receptors at the effector muscle or target organ.

TRUE or FALSE: Stimulation of the sympathetic and parasympathetic divisions cause opposite response.

TRUE

Name the two primary neurotransmitters.

a.

b.

Name the two primary neurotransmitters.

a. Acetylcholine (ACh)

b. Norepinephrine (NE)

Name three other neurotransmitters.

a.

b.

c.

Name three other neurotransmitters.

a. dopamine

b. serotonin

c. GABA (gamma aminobutyric acid)

If your sympathetic nervous system is stimulated, what will you experience?

ACTIVATION

• increased HR, contractility, and BP

• vasoconstriction in periphery (raises BP and shunts blood to skeletal muscles and heart)

• stimulates glycogen breakdown in liver which releases glucose (raises blood sugar)

• adrenal medulla secretes epinephrine and norepinephrine

• increased sweat

• contraction of arrector pili muscles

INHIBITION

• pupil dilation (lets in more light)

• bronchodilation (facilitates breathing which increases O2)

• inhibits digestion (decreased stomach acid secretion, decreases GI motility)

• relaxes smooth muscle in bladder wall but contraction of the internal urethral sphincter (bladder is allowed to fill with urine)

• inhibited salivation

• vasodilation of skeletal muscle blood vessels (increases blood flow to muscles)

• inhibits sex organs

If your parasympathetic nervous system is stimulated, what will you experience?

ACTIVATION

• bronchoconstriction (not as much O2 is needed)

• stimulates digestion (increased stomach acid secretion and increased gastric motility)

• contraction of smooth muscle in bladder wall but relaxation of internal urethral sphincter (causing urination)

• pupil constriction (not as much light is needed)

• stimulated gallbladder

• increased saliva

• stimulated sex organs

INHIBITION

• decreased HR, contractility, and BP

• vasodilation in periphery (lowers BP and allows blood to flow to periphery)

Most organs are innervated by both sympathetic and parasympathetic divisions except:

a.

b.

c.

d.

Most organs are innervated by both sympathetic and parasympathetic divisions except:

a. sweat glands

b. smooth muscles of hair follicles

c. adrenal medulla

d. blood vessels of the brain, skin, and nose

Name the adrenergic receptors:

a.

b.

c.

d.

e.

Name the adrenergic receptors:

a. a-1

b. a-2

c. b-1

d. b-2

e. b-3

Name the cholinergic receptors:

a.

b.

Name the cholinergic receptors:

a. muscarinic

b. nicotinic

Drugs that act as __________ bind to a receptor on the tissue and produce the maximal response.

Drugs that act as agonists bind to a receptor on the tissue and produce the maximal response.

Drugs that act as ___________ bind to a receptor and produce a submaximal response.

Drugs that act as antagonists bind to a receptor and produce a submaximal response.

An a-1 agonist can be used to treat ___________________________________.

An a-1 agonist can be used to treat shock, hypotension, congested eyes/nose.

An a-2 agonist can be used to treat ______________.

An a-2 agonist can be used to treat hypertension.

A b-1 agonist can be used to treat _____________________.

A b-1 agonist can be used to treat hypotension, shock.

A selective b-1 blocker can be used to treat _____________.

A selective b-1 blocker can be used to treat hypertension.

A b-2 agonist can be used to treat __________________.

A b-2 agonist can be used to treat asthma (bronchoconstriction).

___________ decreases saliva and ____________ increases saliva.

Atropine (anticholinergic drug) decreases saliva and pilocarpine (a cholinergic drug) increases saliva.

Which drugs cause the following actions?

• causes paralysis to allow intubation in general anesthesia: ______________

• treats hypertension: _____________

• preoperative medication to reduce saliva: ______________

• causes CNS stimulation and is a vasoconstrictor: _________________

• treatment of severe xerostomia: ________________

Which drugs cause the following actions?

• causes paralysis to allow intubation in general anesthesia: succinylcholine

• treats hypertension: atenolol (Tenormin)

• preoperative medication to reduce saliva: atropine

• causes CNS stimulation and is a vasoconstrictor: epinephrine

• treatment of severe xerostomia: pilocarpine (Salagen)

Atropine is an _____________ drug.

Atropine is an anticholinergic drug.

Name six uses for atropine:
a.

b.

c.

d.

e.

f.

Name six uses for atropine:
a. pupil dilation

b. tx bradycardia after MI

c. tx GI and bladder spasms

d. prevents motion sickness

e. tx excessive muscle movement, especially of the face and neck (e.g. acute dystonia bc of phenothiazines/antipsychotics)

f. counteracts organophosphate poisoning

Nervous System (NS) Structure

NS: Nervous System

1. CNS: Central Nervous System (brain and spinal cord)

2. PNS: Peripheral Nervous System (cranial nerves and spinal nerves)

   • SNS: Somatic Nervous System (voluntary control of skeletal muscles and processes sensory information)

   • ANS: Autonomic Nervous System (automatic modulating system for many body functions; involuntary responses of the heart muscle, smooth muscle, glands)

     • SANS: Sympathetic Autonomic Nervous System (“fight or flight”)

     • PANS: Parasympathetic Autonomic Nervous System (“rest and digest”)

Autonomic Nervous System (ANS): PANS vs SANS

Each branch of the ANS (SANS and PANS) has different characteristics and usually cause opposite responses (activation vs inhibition). Most organs are innervated by both the SANS and PANS (with some exceptions).

.

SANS: Sympathetic Autonomic Nervous System (“fight or flight”)

• neurons: originate in thoracolumbar portion of spinal cord

• organs: heart, eyes, lungs, blood vessels, kidneys, stomach, intestines, bladder, secretory glands (+ sweat glands, smooth muscles of hair follicles, adrenal medulla, blood vessels of the skin/brain/nose)

• preganglionic (presynaptic) neurons: SHORT

• postganglionic (postsynaptic) neurons: LONG

• postganglionic receptors: adrenergic (a-1, a-2, b-1, b-2, b-3)

• neurotransmitters: NE (norepinephrine)

• action: body responds to stressful events (“fight or flight”)

.

PANS: Parasympathetic Autonomic Nervous System (“rest and digest”)

• neurons: originate from four cranial nerves (III, VII, IX, X) and from the sacral regions (S2-5)

• organs: heart, eyes, lungs, blood vessels, kidneys, stomach, intestines, bladder, secretory glands

• preganglionic (presynaptic) neurons: LONG

• postganglionic (postsynaptic) neurons: SHORT

• postganglionic receptors: cholinergic (nicotinic/muscarinic)

• neurotransmitters: acetylcholine (ACh)

• action: activates bodily processes during times of rest (“rest and digest”)

.

Organs innervated ONLY by the SANS:

• sweat glands

  • postganglionic neurons release ACh INSTEAD of NE

  • ACh acts on muscarinic receptors (usually associated with the PANS) to cause sweating

• stimulates smooth muscles of hair follicles

• adrenal medulla

  • only PREganglionic nerves innervate the adrenal medulla (NOT POSTganglionic)

  • ACh causes the adrenal medulla to release epi & NE

• blood vessels of the skin, brain, and nose

  • NE causes vasoconstriction of the blood vessels that carry blood to the skeletal muscles, skin, brain, and nose

Neurotransmitters

Neurotransmitters: chemical substances made in neurons that are released when an AP comes along the neuron, carrying the AP across the synapse to allow neuron-neuron and neuron-organ communication

• primary neurotransmitters: ACh & NE

• ACh is released from ALL PREGANGLIONIC neurons to communicate with the postganglionic neurons; preganglionic neurons are CHOLINERGIC

• SANS: NE is released from the POSTGANGLIONIC neuron; these neurons are ADRENERGIC

• PANS: ACh is released from the POSTGANGLIONIC neuron; these neurons are CHOLINGERGIC

.

Other types of neurotransmitters:

• Epinephrine (aka ADRENaline; an ADRENergic neurotransmitter produced by the ADRENal medulla)

• Dopamine (cholinergic)

  • produced in the brain by dopaminergic neurons

  • role: executive function, motor control, motivation, arousal, reinforcement, reward

• Serotonin

  • produced primarily by platelets, GI tract cells, neurons

  • role: platelet aggregation, stimulation of GI motility, vasoconstriction, controls sleep/pain/behavior/emotions

• GABA (aka gamma aminobutyric acid)

  • produced in the brain

  • role: inhibits nerve transmission to produce a calming effect; thought to play a role in controlling anxiety, stress, and fear

Receptors

Receptors receive neurotransmitters released from the axonal terminals of the neuron. The type of neurotransmitter and receptor dictates the tissue/organ response.

SANS receptors:

• preganglionic: cholinergic (nicotinic (ACh))

• postganglionic: adrenergic (NE)

  • alpha: a-1, a-2

  • beta: b-1, b-2, b-3

PANS receptors:

• preganglionic: cholinergic (nicotinic (ACh))

• postganglionic: cholinergic (nicotinic or muscarinic (ACh))

—

Excess neurotransmitters are removed from the synapses by enzymes.

• enzymes biotransform the neurotransmitters into an inactive metabolite

• reputake: the process where neurotransmitters are taken back up into the axon terminal where it is then inactivated by enzymes

Effects of PANS

ACTIVATION

• bronchoconstriction (not as much O2 is needed)

• digestion (increased stomach acid secretion and increased gastric motility)

• contraction of smooth muscle in bladder wall but relaxation of internal urethral sphincter (causing urination)

• pupil constriction (miosis) (not as much light is needed)

• stimulated gallbladder

• increased saliva

• stimulated sex organs

INHIBITION

• decreased HR, contractility, and BP

• vasodilation in periphery (lowers BP and allows blood to flow to periphery)

Effects of SANS

ACTIVATION

• increased HR, contractility, and BP

• vasoconstriction in periphery (raises BP and shunts blood to skeletal muscles and heart)

• stimulates glycogen breakdown in liver which releases glucose (raises blood sugar)

• adrenal medulla secretes epinephrine and norepinephrine

• increased sweat

• contraction of arrector pili muscles

INHIBITION

• pupil dilation (mydriasis) (lets in more light)

• bronchodilation (facilitates breathing which increases O2)

• inhibits digestion (decreased stomach acid secretion, decreases GI motility)

• relaxes smooth muscle in bladder wall but contraction of the internal urethral sphincter (bladder is allowed to fill with urine)

• inhibited salivation

• vasodilation of skeletal muscle blood vessels (increases blood flow to muscles)

• inhibits sex organs

SANS Receptors

ALPHA

• a-1: STIMULATE

  • location: smooth muscle and glands (blood vessels, genitourinary system, sweat glands, eyes, intestine), adrenal medulla

  • action: contraction of peripheral blood vessels = shunting of blood to skeletal muscles and heart & increased BP; stimulates adrenal medulla to secrete epinephrine

• a-2: INHIBIT

  • location: same as a-1

  • action: acts like a negative feedback loop by inhibiting the SANS from having too great of an effect; inhibits NE release, decreases secretion of insulin (increases blood sugar), decreases contraction of peripheral blood vessels (decreases BP), decreases eye secretions

• note: alpha receptors are autoreceptors: a type of receptor that is sensitive to the neurotransmitters released by the neuron on which it sits

BETA

• b-1: STIMULATE

  • location: heart & kidneys

  • action: stimulates heart tissue (increased HR and contractility), stimulates kidneys (increased BP and blood volume)

• b-2: INHIBIT

  • location: smooth muscle (bronchial, uterine, blood vessels)

  • action: relaxes smooth muscles and causes bronchodilation

• b-3: found in/on fat tissue

PANS Receptors

Muscarinic Receptors

• location: skeletal muscles, eyes, gut, penis, lungs (and sweat glands, but they are innervated by SANS)

• action: increased secretions, bronchoconstriction, miosis (pupil constriction), erection

Nicotinic Receptors

• location: skeletal muscle and CNS

• action: contraction of skeletal muscles and neurotransmission in the CNS

Types of Drugs

Action:

• AGONISTS: bind to receptors and produce a maximal response

  • sympathoMIMETIC, parasympathoMIMETIC

• ANTAGONISTS (“blockers”): bind to receptors and produce a submaximal response

  • sympathoLYTIC, parasympathoLYTIC

Method:

• Direct Acting

• Indirect Acting

• Mixed Action: activates both a-1 and b-2 receptors by direct and indirect methods

Types of Adrenergic Drugs:

• selective

• nonselective

Adrenergic Agonist Drugs (Sympathomimetics)

Types:

• direct-acting a-1 agonist

• direct-acting a-2 agonist

• direct-acting b-1 agonist

• direct-acting b-2 agonist

• indirect-acting

• mixed-acting

Side Effects of Adrenergic AGONIST Drugs:

• hyposalivation, nausea, vomiting, headache, dizziness, palpitations

• nonselective b-agonists can cause hyperglycemia (decreased insulin release = increased blood sugar)

Direct-Acting ALPHA Adrenergic AGONIST Drugs

a-1 Agonists

• action: activate a-1 receptors

  • stimulates smooth muscle contraction → vasoconstriction (elevates BP and shunts blood to skeletal muscles), dilation of pupils (lets more light in), contraction of bladder wall muscles (allows bladder to fill)

• use: tx of shock and hypotension, nasal/ocular decongestant

• drug examples:

  • Phenylephrine (Neo-Synephrine)

  • Oxymetazoline (Afrin)

  • Atropine

---

a-2 Agonists

• action: stimulates a-2 receptors

  • inhibits release of NE → decreased peripheral vasoconstriction and decreased stimulation of heart muscle → decreased HR and decreased BP

• use: tx of hypertension (decreases HR which lowers BP)

• drug examples:

  • Clonidine (Catapres)

Direct-Acting BETA Adrenergic AGONIST Drugs

b-1 Agonists

• action: activates b-1 receptors

  • stimulates the heart muscle → increased HR and force

• use: tx hypotension and shock (given via IV)

• drug examples:

  • Isoproterenol

  • Epinephrine

  • Levonordefrin

  • Ephedrine

note: can be SELECTIVE (b-1 only) or NON-SELECTIVE (b-1 and b-2)

---

b-2 Agonists

• action: activates b-2 receptors

  • inhibits smooth muscle contraction → bronchodilation

• use: bronchodilation in asthmatics

• drug examples: albuterol (terbutaline)

note: SELECTIVE b-2 agonist drugs have LESS side effects on the heart (e.g. albuterol), but there is always still some action on the beta-1 receptors (e.g. albuterol causes some tachycardia even though it is a selective b-2 agonist)

Indirect-Acting Adrenergic Agonist Drugs

• drug examples:

  • Amphetamine: used to tx narcolepsy and ADHD

Mixed-Acting Adrenergic Agonist Drugs

• action: activates both a-1 and b-2 receptors by direct and indirect methods

• use: nasal decongestants (stimulates a-1 receptors → vasoconstriction of blood vessels in the nose)

• drug examples:

  • Ephedrine and pseudoephedrine (Sudafed)

Adrenergic Antagonist Drugs (Sympatholytics)

Adrenergic Antagonist Drugs should NOT be used in diabetics because they increase insulin action which reduces blood sugar and can cause hypoglycemia.

.

Beta-Blockers:

uses: tx of hypertension, urinary retention, headaches (migraines), glaucoma (increased interocular pressure)

Side Effects:

• NSAID drug interaction

• xerostomia

• orthostatic hypotension

• heart failure or heart block

• nonselective beta-blockers:

  • use caution with epi — use cardiac dose and consider overall cardiac condition

  • NEVER USE IN ASTHMATICS; can cause bronchoconstriction

• selective beta-blockers:

  • no special precautions with epi, but consider overall cardiac condition

  • okay to use in asthmatics

Drug Interactions:

• additive hypotensive effects with concurrent use of phenothiazines (antipsychotics) with beta-blockers

.

Alpha-Blockers:

Side Effects:

• postural hypotension, bradycardia, and dizziness with initial doses (hence why they aren’t prescribed as much as beta-blockers)

Drug Interactions:

• additive hypotensive effects with concurrent use of antihypertensive or diuretic drugs with a-1 blockers

ALPHA Adrenergic ANTAGONIST Drugs

a-1 Antagonists

• action: blocks a-1 receptors (can be selective or nonselective)

  • blocks vasoconstrictive actions of NE and epi

• use:

  • tx hypertension by blocking the vasoconstrictive actions of NE and epi on vascular smooth muscle

  • nonselective a-1 adrenergic blockers: bind BOTH a-1 & a-2 receptors on smooth muscles of blood vessels

  • selective a-1 adrenergic blockers: tx hypertension and prostate enlargement

• drug examples:

  • Prazosin (Minipress)

  • Terazosin (Hytrin)

---

a-2 Antagonists

• action: blocks a-2 receptors selectively

• use:

• drug examples:

  • Yohimbine (Yocon): tx of impotency in men

Beta Adrenergic Antagonist Drugs

• action: blocks b-1 and/or b-2 receptors (can be selective or nonselective)

• use: tx of hypertension, angina, heart arrythmias, panic attacks, migraines, glaucoma, tremors

• drug examples:

  • NONSELECTIVE beta-adrenergic antagonists:

    • Propranolol (Inderal)

    • Timolol (Blocadren)

    • Nadolol (Corgard)

    • Labetalol (Normodyne) 

  • SELECTIVE beta-adrenergic antagonists: have a greater affinity for b-1 receptors than for b-2 receptors; referred to as “cardio-selective beta-blockers” because b-1 receptors are primarily located on heart tissue)

    • Atenolol (Tenormin)

    • Acebutolol (Sectral)

    • Metoprolol (Lopressor)

Cholinergic Drugs

Cholinergics: agonist drugs that act as mediators of cholinergic (ACh) transmission; aka parasympathomimetics

• use: tx of xerostomia (cevimeline, pilocarpine) and Alzheimer’s disease (donepezil, tacrine, rivastigmine)

• types:

  • Direct-Acting: acts like ACh at receptor sites

  • Indirect-Acting: inhibits cholinesterase to indirectly increase the amount of ACh; can be reversible or irreversible

Anticholinergics: antagonist drugs that block cholinergic (ACh) transmission; aka parasympatholytics

• use: increase HR (atropine), treats urinary incontinence (oxybutynin), motion sickness (scopolamine), and IBS (dicyclomine, propantheline, scopolamine)

• adverse effects: xerostomia, urinary retention, blurred vision, constipation, tachycardia

• drug interactions: additive cholinergic side effects are seen when anticholinergics are used concurrently with drugs that also have anticholinergic effects (e.g. TCAs, antihistamines such as Benadryl)

note: Benadryl’s (diphenhydramine) effects on the PANS has been linked to dementia! Benadryl helps you sleep, but you aren’t resting.

Direct-Acting Cholinergic Agonist Drugs

• have an affinity for cholinergic receptors (either nicotinic or muscarinic, but ideally muscarinic bc these muscarinic receptors are found at organ sites)

• action: acts like ACh at receptor sites

  • slows HR, increases smooth muscle tone of the GI and urinary tract (may result in nausea and evacuation of the bladder — this is why you are asked to fast and urinate before going under anesthesia)

• drug examples:

  • Acetylcholine: no clinical use because it is rapidly broken down and has many adverse effects

  • Bethanechol (Urecholine)

  • natural plant alkaloids:

    • Pilocarpine (Salagen): obtained from a plant shrub and is used to treat hyposalivation but has adverse effects such as flushing, sweating, urinary urgency

    • Nicotine: obtained from tobacco plants and is used in cigarettes and other tobacco products

    • Muscarine: obtained from certain mushrooms and is lethal

Indirect-Acting Cholinergic Agonist Drugs

• action: inhibits cholinesterase (the enzyme that breaks down ACh), thereby allowing ACh to accumulate at receptor sites; show a mixture of muscarinic and nicotinic effects

• two classes:

  • Reversible

    • Neostigmine and Pyridostigmine: used to tx symptoms of myasthenia gravis (autoimmune disorder where Ab destroy communication between nerves and muscle causing voluntary muscle weakness, especially in those that control the eyes, mouth, throat, and limbs)

    • Physostigmine: tx glaucoma

    • Donepezil (Aricept) and Tacrine (Cognex): centrally-acting drugs that concentrate in the brain and are used to tx Alzheimer’s

  • Irreversible: highly lipid soluble (absorbed easily through skin/eyes)

    • Pesticides (organophosphates)

    • Nerve gases (Tabun, sarin, soman)

Muscarinic Receptor Antagonist Drugs (Anticholinergics)

Drug Examples:

• belladonna alkaloids:

  • Atropine

  • Scopolamine: tx motion sickness

• Semisynthetic and synthetic muscarinic receptor antagonists:

  • Dicyclomine (Bentyl) and Propantheline (Pro-Banthine): synthetic agents with a strong affinity to muscarinic receptors within the GI tract; used to decrease GI motility in IBS

• Tolterodine (Detrol): tx urinary incontinence

• Succinylcholine: causes paralysis and is used to allow intubation during general anesthesia

• Atropine

note: foods such as tomatoes, peppers, white potatoes, and eggplant are part of the Belladonna (nightshade) family and should be avoided in people with arthritis

Atropine

Atropine: an anticholinergic drug that INHIBITS salivation (pilocarpine is a cholinergic drug that INCREASES salivation)

Indications:

• ocular: dilation (mydriasis) to facilitate eye exams

• cardiac: tx bradycardia after MI

• GI and urinary tract: tx GI and bladder spasms

• CNS: prevents motion sickness, tx excessive muscle movements (especially those of the face and neck in acute dystonia caused by antipsychotic meds)

• counteracts organophosphate poisoning