5 autonomic drugs (1)

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Mosby items and derived items 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 5Chapter 5

Autonomic DrugsAutonomic Drugs


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Autonomic PharmacologyAutonomic Pharmacology

Autonomic Nervous SystemAutonomic Nervous System This system is divided into two separateThis system is divided into two separate

systems.systems.

These systems are called the parasympatheticThese systems are called the parasympatheticnervous system and the sympathetic nervousnervous system and the sympathetic nervous

system.system.

These systems often produce opposite effects.These systems often produce opposite effects.

Drugs in this group are designed to eitherDrugs in this group are designed to eitherenhance or mimic the autonomic nervous systemenhance or mimic the autonomic nervous system

or to block the effects of the neurotransmitters ator to block the effects of the neurotransmitters at

their receptor sites.their receptor sites.

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Autonomic Nervous SystemAutonomic Nervous System

Parasympathetic Nervous SystemParasympathetic Nervous System This system is concerned with the conservationThis system is concerned with the conservation

of the body processes.of the body processes.

Its main neurotransmitter is acetylcholine.Its main neurotransmitter is acetylcholine. Its receptors are muscarinic, nicotinic, and theIts receptors are muscarinic, nicotinic, and the

somatic-skeletal muscles.somatic-skeletal muscles.

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Autonomic Nervous SystemAutonomic Nervous System

Sympathetic Nervous SystemSympathetic Nervous System This nervous system is designed to cope withThis nervous system is designed to cope with

emergency situations.emergency situations.

This is commonly known as the fright or flightThis is commonly known as the fright or flightresponse.response.

Its neurotransmitters are epinephrine andIts neurotransmitters are epinephrine and

norepinephrine.norepinephrine.

Its receptors are theIts receptors are the andand receptors.receptors.

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Cholinergic or Parasympathomimetic DrugsCholinergic or Parasympathomimetic Drugs These drugs are classified as either direct or indirectThese drugs are classified as either direct or indirect

acting agents.acting agents.

Direct acting drugs act directly on theDirect acting drugs act directly on theparasympathetic receptors.parasympathetic receptors.

Indirect acting drugs work by either of two methods.Indirect acting drugs work by either of two methods.

They can cause the release of the neurotransmitterThey can cause the release of the neurotransmitter

which then goes to the receptor site or they inhibit thewhich then goes to the receptor site or they inhibit the

enzyme cholinesterase.enzyme cholinesterase.

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Cholinergic PharmacologyCholinergic Pharmacology CardiovascularCardiovascular

Direct effects include negative chronotropic andDirect effects include negative chronotropic andinotropic actions.inotropic actions.

Relaxation of smooth muscles causes a decrease inRelaxation of smooth muscles causes a decrease intotal peripheral resistance.total peripheral resistance.

Indirect effects include increased heart rate andIndirect effects include increased heart rate andcardiac output.cardiac output.

The resulting effect depends upon the dose used.The resulting effect depends upon the dose used.

Usually, the patient experiences bradycardia and aUsually, the patient experiences bradycardia and adecrease in blood pressure and cardiac output.decrease in blood pressure and cardiac output.

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Cholinergic PharmacologyCholinergic Pharmacology GastrointestinalGastrointestinal

These drugs excite the smooth muscle of theThese drugs excite the smooth muscle of the

gastrointestinal tract and cause an increase ingastrointestinal tract and cause an increase inactivity, motility, and secretion.activity, motility, and secretion.

EyeEye

These drugs cause miosis and cycloplegia.These drugs cause miosis and cycloplegia.

They cause a decrease in intraocular pressure.They cause a decrease in intraocular pressure.

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Adverse ReactionsAdverse ReactionsAdverse reactions are an extension of theAdverse reactions are an extension of the

drugs pharmacologic effects.drugs pharmacologic effects.

They include:They include: SalivationSalivation LacrimationLacrimation UrinationUrination DefecationDefecation

ParalysisParalysis OverdoseOverdose

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Cholinergic PharmacologyCholinergic Pharmacology

ContraindicationsContraindications The contraindications and relative cautions areThe contraindications and relative cautions are

a result of the drugs pharmacologic anda result of the drugs pharmacologic and

adverse effects.adverse effects. They include:They include:

Bronchial asthmaBronchial asthma

HyperthyroidismHyperthyroidism

Gastrointestinal or urinary tract obstructionGastrointestinal or urinary tract obstruction Myasthenia gravis treated with neostigmineMyasthenia gravis treated with neostigmine

Peptic ulcer diseasePeptic ulcer disease

Severe cardiac diseaseSevere cardiac disease

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Cholinergic DrugsCholinergic Drugs

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Anticholinergic DrugsAnticholinergic Drugs

These drugs prevent the action ofThese drugs prevent the action of

acetylcholine at postganglionicacetylcholine at postganglionic

parasympathetic endings.parasympathetic endings.

Acetylcholine is released but its receptor siteAcetylcholine is released but its receptor site

is completely blocked by anticholinergicis completely blocked by anticholinergic

drugs.drugs.

These drugs only block muscarinic receptors.These drugs only block muscarinic receptors.

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PharmacologyPharmacology Central Nervous SystemCentral Nervous System

Depending on the dose, these drugs can causeDepending on the dose, these drugs can cause

stimulation or depression.stimulation or depression. Exocrine GlandsExocrine Glands

They reduce the flow and volume of secretions in theThey reduce the flow and volume of secretions in therespiratory, gastrointestinal, and genitourinary tracts.respiratory, gastrointestinal, and genitourinary tracts.

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PharmacologyPharmacology Smooth MuscleSmooth Muscle

Relax smooth muscles in the respiratory andRelax smooth muscles in the respiratory and

gastrointestinal tracts.gastrointestinal tracts. They delay gastric emptying and decreaseThey delay gastric emptying and decrease

esophageal and gastric emptying.esophageal and gastric emptying.

These drugs also cause bronchial dilation.These drugs also cause bronchial dilation.

EyeEye

These drugs cause mydriasis and cycloplegia.These drugs cause mydriasis and cycloplegia.

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PharmacologyPharmacology CardiovascularCardiovascular

With large doses, these drugs produce vagalWith large doses, these drugs produce vagal

blocking which results in tachycardia.blocking which results in tachycardia. Bradycardia can occur with low doses.Bradycardia can occur with low doses.

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Adverse ReactionsAdverse Reactions The adverse reactions are an extension of theThe adverse reactions are an extension of the

drugs pharmacologic effects.drugs pharmacologic effects.

They include:They include: XerostomiaXerostomia ConstipationConstipation Urinary retentionUrinary retention Blurred visionBlurred vision

HyperpyrexiaHyperpyrexia HallucinationsHallucinations PhotophobiaPhotophobia TachycardiaTachycardia

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ContraindicationsContraindications Contraindications are usually due to the drugsContraindications are usually due to the drugs

pharmacologic and adverse effects.pharmacologic and adverse effects.

They include:They include: GlaucomaGlaucoma

Prostatic hypertrophyProstatic hypertrophy

Intestinal or urinary obstruction or retentionIntestinal or urinary obstruction or retention

Cardiovascular diseaseCardiovascular disease

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UsesUses Preoperative MedicationPreoperative Medication

They inhibit salivary and bronchial secretions.They inhibit salivary and bronchial secretions.

They block the vagal slowing of the heart that canThey block the vagal slowing of the heart that canoccur with general anesthesia.occur with general anesthesia.

Gastrointestinal DisordersGastrointestinal Disorders

They decrease gastrointestinal motility and can beThey decrease gastrointestinal motility and can beused to treat ulcers, diarrhea, and hypermotility.used to treat ulcers, diarrhea, and hypermotility.

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UsesUses Ophthalmologic ExaminationsOphthalmologic Examinations

Topical use can cause mydriasis which causes a fullTopical use can cause mydriasis which causes a full

visualization of the retina.visualization of the retina. Cycloplegia relaxes the lens so that properCycloplegia relaxes the lens so that proper

prescriptions for glasses can be determined.prescriptions for glasses can be determined.

Parkinson DiseaseParkinson Disease

They reduce the tremors and rigidity associated withThey reduce the tremors and rigidity associated withParkinson and drug-induced Parkinson disease.Parkinson and drug-induced Parkinson disease.

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UsesUses Motion SicknessMotion Sickness

These drugs are used to treat or prevent motionThese drugs are used to treat or prevent motion

sickness because of their central nervous systemsickness because of their central nervous systemdepressant action.depressant action.

DentistryDentistry

These drugs are used to create a dry, oral field.These drugs are used to create a dry, oral field.

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Adrenergic DrugsAdrenergic Drugs

Adrenergic drugs can be classified as having directAdrenergic drugs can be classified as having directaction, indirect action, or mixed action.action, indirect action, or mixed action.

These drugs stimulateThese drugs stimulate andand receptors throughoutreceptors throughoutthe body.the body.

Drugs with direct action (epinephrine, norepinephrine,Drugs with direct action (epinephrine, norepinephrine,isoproterenol) produce their effect by directlyisoproterenol) produce their effect by directlystimulating the receptor site.stimulating the receptor site.

Drugs with indirect action (amphetamine) releaseDrugs with indirect action (amphetamine) releaseendogenous norepinephrine which then stimulatesendogenous norepinephrine which then stimulates

the receptor.the receptor. Drugs with mixed action (ephedrine) either directlyDrugs with mixed action (ephedrine) either directly

stimulate the receptor or release endogenousstimulate the receptor or release endogenousnorepinephrine.norepinephrine.

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PharmacologyPharmacology Central Nervous System (CNS)Central Nervous System (CNS)

These drugs produce CNS excitation or alertness.These drugs produce CNS excitation or alertness.

Higher doses produce anxiety, apprehension,Higher doses produce anxiety, apprehension,restlessness, and tremors.restlessness, and tremors.

Cardiovascular SystemCardiovascular System

These drugs increase the force and rate ofThese drugs increase the force and rate ofcontraction of the heart.contraction of the heart.

Blood pressure is also increased.Blood pressure is also increased.

Total peripheral resistance is also increased.Total peripheral resistance is also increased.

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PharmacologyPharmacology EyeEye

These drugs lower intraocular pressure and can causeThese drugs lower intraocular pressure and can causemydriasis.mydriasis.

Respiratory SystemRespiratory System These drugs cause a relaxation of bronchiole smoothThese drugs cause a relaxation of bronchiole smooth

muscles.muscles.

Metabolic EffectsMetabolic Effects Increased glycogenolysis fromIncreased glycogenolysis from -receptor stimulation-receptor stimulation

causes hyperglycemia.causes hyperglycemia. Salivary GlandsSalivary Glands These drugs produce vasoconstriction of the salivaryThese drugs produce vasoconstriction of the salivary

glands which leads to decreased salivary flow whichglands which leads to decreased salivary flow whichresults in xerostomia.results in xerostomia.

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Adverse ReactionsAdverse Reactions The adverse reactions associated with theseThe adverse reactions associated with these

drugs are an extension of the drugsdrugs are an extension of the drugspharmacologic effects.pharmacologic effects.

They include:They include: AnxietyAnxiety TremorsTremors TachycardiaTachycardia

Increased blood pressureIncreased blood pressure ArrhythmiasArrhythmias

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UsesUses VasoconstrictionVasoconstriction

These drugs are used in dentistry because of theirThese drugs are used in dentistry because of theirvasoconstrictive actions on blood vessels. They arevasoconstrictive actions on blood vessels. They are

added to local anesthetics because they prolong theadded to local anesthetics because they prolong theaction of the local anesthetic, reduce the risk foraction of the local anesthetic, reduce the risk forsystemic toxicity, and help to create a dry field.systemic toxicity, and help to create a dry field.

Cardiac EffectsCardiac Effects These drugs are used to raise blood pressure and toThese drugs are used to raise blood pressure and to

treat cardiac arrest.treat cardiac arrest.

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UsesUses BronchodilationBronchodilation

These drugs are used to treat asthma, emphysema,These drugs are used to treat asthma, emphysema,

and allergic reaction.and allergic reaction. Central Nervous System StimulationCentral Nervous System Stimulation

These medications are used for the treatment ofThese medications are used for the treatment ofattention deficit hyperactivity disorder, narcolepsy,attention deficit hyperactivity disorder, narcolepsy,

and as diet aids.and as diet aids.

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Adrenergic Blocking DrugsAdrenergic Blocking Drugs

These drugs competitively inhibitThese drugs competitively inhibit andand receptor sites.receptor sites.

One group of drugs is specific forOne group of drugs is specific for

receptors.receptors. One group of drugs is specific for bothOne group of drugs is specific for both

11andand

22receptors.receptors.

One group is specific forOne group is specific for22receptors.receptors.

One group is specific for bothOne group is specific for both andand receptors.receptors.

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Mosb items and deri ed items 2007 b Mosb Inc an affiliate of Else ier Inc

Antiadrenergic DrugsAntiadrenergic Drugs

PharmacologyPharmacology These drugs reduce sympathetic tone in theThese drugs reduce sympathetic tone in the

blood vessels and decrease total peripheralblood vessels and decrease total peripheral

resistance.resistance. This results in a reduction in blood pressure.This results in a reduction in blood pressure.

UsesUses These drugs are used to treat hypertension,These drugs are used to treat hypertension,

peripheral vascular disease (i.e., Raynaudperipheral vascular disease (i.e., Raynaudsyndrome) and benign prostatic hypertrophy.syndrome) and benign prostatic hypertrophy.

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5 autonomic drugs (1)

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