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Chapter 10Chapter 10Analgesics And Local Analgesics And Local Anesthetics Anesthetics

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IntroductionIntroduction

At times athletes, coaches, and others At times athletes, coaches, and others will self-prescribe or encourage the use will self-prescribe or encourage the use of analgesics and/or local anesthetics to of analgesics and/or local anesthetics to allow players to participate in a contest allow players to participate in a contest

Pain tells us something!! Pain can be Pain tells us something!! Pain can be masked by meds, can lead to further masked by meds, can lead to further damagedamage

OTC meds used for short term relief, OTC meds used for short term relief, physician referral for continued painphysician referral for continued pain

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Pain-Control OptionsPain-Control Options

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AnalgesicsAnalgesics

An analgesic is a drug or preparation An analgesic is a drug or preparation that will reduce or eliminate pain.that will reduce or eliminate pain.

Two categories: Non-opioids & Two categories: Non-opioids & opioids opioids

Opioid – from the opium poppyOpioid – from the opium poppy– Well known to relieve moderate and/or Well known to relieve moderate and/or

severe pain symptomssevere pain symptoms– Semi-synthetic and synthetic derivativesSemi-synthetic and synthetic derivatives

Two of the most noted of these compounds Two of the most noted of these compounds are morphine and codeineare morphine and codeine

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Adverse effect – physical Adverse effect – physical dependencedependence– Usually develop symptoms when Usually develop symptoms when

patient stops taking drugpatient stops taking drug– Withdrawal signs and symptomsWithdrawal signs and symptoms

Irritability, sweating, insomnia, Irritability, sweating, insomnia, tachycardiatachycardia

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Endogenous opioidsEndogenous opioids

Endorphins and enkephalins are Endorphins and enkephalins are circulating throughout the body on an circulating throughout the body on an “as-needed”“as-needed” basis. basis.

The endorphins are naturally The endorphins are naturally occurring morphine-like substances occurring morphine-like substances and are thought to bind to receptor and are thought to bind to receptor sites on the pain mediating pathways. sites on the pain mediating pathways.

The enkephalins have a similar The enkephalins have a similar function to the endorphins; they bind function to the endorphins; they bind to different receptor sites but provide to different receptor sites but provide the same type of pain mediation. the same type of pain mediation.

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Endogenous Opioids Endogenous Opioids ((cont.cont.)) These endogenous opioids are These endogenous opioids are

considered to be more potent considered to be more potent than morphine.than morphine.

Endogenous opioids are available Endogenous opioids are available to the CNS for analgesia.to the CNS for analgesia.– Not in the concentration of Not in the concentration of

exogenous opioids. exogenous opioids.

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Opioids’ Mechanism of Opioids’ Mechanism of ActionAction Identified in the peripheral nerves.Identified in the peripheral nerves.

– Endogenous opioids bind and Endogenous opioids bind and decrease the excitability of the decrease the excitability of the peripheral sensory neurons = peripheral sensory neurons = analgesia.analgesia.

Receptors are classified into three Receptors are classified into three categories: ( Table 10-3, pg 136)categories: ( Table 10-3, pg 136)– Mu (µ) Mu (µ) – Kappa (Kappa ())– Delta (Delta () )

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Exogenous OpioidsExogenous Opioids

Tightly controlled prescription Tightly controlled prescription medication, potential for addictionmedication, potential for addiction

Mainly used for cancer patientsMainly used for cancer patients Can be used for postsurgical pain Can be used for postsurgical pain

controlcontrol Acute pain situations should not Acute pain situations should not

need opioids after 1 weekneed opioids after 1 week

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Table 10-4: Oral Opioid Table 10-4: Oral Opioid AnalgesicsAnalgesics

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Specific AgentsSpecific Agents

2004 – 2.04 billion prescriptions for 2004 – 2.04 billion prescriptions for hydrocodone were writtenhydrocodone were written

Hydrocodone combined with Hydrocodone combined with acetaminophen has antitussive acetaminophen has antitussive action; most commonly prescribed action; most commonly prescribed for painfor pain

Oxycodone (OxyContin, Percocet, Oxycodone (OxyContin, Percocet, Percodan, Oxycodone, etc.) Percodan, Oxycodone, etc.) – Prepared in combination with Prepared in combination with

acetaminophen or other similar acetaminophen or other similar analgesics. analgesics.

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Codeine is another mild to moderate Codeine is another mild to moderate analgesic that can be prescribed by analgesic that can be prescribed by the physician or dentist to alleviate the physician or dentist to alleviate pain in the athlete. pain in the athlete.

Codeine is also used as an Codeine is also used as an antitussive.antitussive.

Adverse effect of codeine is Adverse effect of codeine is constipationconstipation

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Adverse Effects Of Adverse Effects Of Exogenous OpioidsExogenous Opioids

SedationSedation Nausea/vomitingNausea/vomiting ConstipationConstipation

– Paragoric was used as an anti-diahrrealParagoric was used as an anti-diahrreal Opioids with alcohol or other CNS Opioids with alcohol or other CNS

depressants has an additive effect = depressants has an additive effect = lethallethal

Physicians be aware of any person who Physicians be aware of any person who has addictive behaviors before they has addictive behaviors before they prescribe one of the opioids for prescribe one of the opioids for analgesiaanalgesia

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Table 10-5: Screening Table 10-5: Screening Questions for Potential Questions for Potential Opioid Abuse Opioid Abuse

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Opioids can induce a tolerance effectOpioids can induce a tolerance effect– Means that an increasing amount of the Means that an increasing amount of the

drug is required to maintain the same drug is required to maintain the same level of analgesialevel of analgesia

– Affected by dose, frequency, regularityAffected by dose, frequency, regularity– Does not indicate addictionDoes not indicate addiction– Normal if taken for long periods of timeNormal if taken for long periods of time

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Rehabilitation Rehabilitation

As mentioned, opioids can create As mentioned, opioids can create sedation, drowsiness, and an overall sedation, drowsiness, and an overall mental “slow down.” mental “slow down.”

It is wise to schedule rehabilitation It is wise to schedule rehabilitation or other activities that require or other activities that require mental acuity at times when the mental acuity at times when the drug is at a period of reduced drug is at a period of reduced activity.activity.

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Nonopioid Nonopioid PreparationsPreparations NSAIDsNSAIDs Propoxyphene (Darvon, Darvocet)Propoxyphene (Darvon, Darvocet)

– High rate of addictionHigh rate of addiction– Significant toxic when combined Significant toxic when combined

with other medswith other meds– Ranks 2Ranks 2ndnd to barbiturates in causing to barbiturates in causing

fatalitiesfatalities

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Capsaicin (Zostrix)Capsaicin (Zostrix)– Derived from seeds of hot chili Derived from seeds of hot chili

pepperspeppers– Arthritic or atypical pain, now more Arthritic or atypical pain, now more

for athletesfor athletes– Topically applied creamTopically applied cream

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Athletes’ Athletes’ Understanding of Understanding of Analgesic DrugsAnalgesic Drugs Monitor OTC product use – reduction Monitor OTC product use – reduction

in pain may allow for further damagein pain may allow for further damage Athlete should report use of herbal Athlete should report use of herbal

products because of adverse products because of adverse interactionsinteractions

ATC must watch for signs of ATC must watch for signs of addictionaddiction

What to Tell the Athlete, pg 140 What to Tell the Athlete, pg 140

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Local AnestheticsLocal Anesthetics

The use of a drug or preparation to The use of a drug or preparation to produce partial or complete loss of produce partial or complete loss of sensation to a specific areasensation to a specific area

Commonly used in a physician’s Commonly used in a physician’s clinical practice, injectionsclinical practice, injections

Origination of local anesthetics Origination of local anesthetics –– during the 1500sduring the 1500s

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Local Anesthetics Local Anesthetics ((cont.cont.)) ““Caine” suffix (cocaine)Caine” suffix (cocaine)

– Incas used the cocoa leaf as a local Incas used the cocoa leaf as a local anesthetic anesthetic

– 1800s – cocaine was derived from 1800s – cocaine was derived from the cocoa leaf the cocoa leaf

– Liquid solution was used for local Liquid solution was used for local anesthetic purposesanesthetic purposes

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Local Anesthetic Local Anesthetic ActionAction Diminishes the ability of the Diminishes the ability of the

nerve fiber to conduct action nerve fiber to conduct action potentials.potentials.

Pain perception is decreased Pain perception is decreased followed by decrease in motor followed by decrease in motor control.control.

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Use of Local Use of Local AnestheticsAnesthetics Minor surgical proceduresMinor surgical procedures Dental proceduresDental procedures OthersOthers

– Diagnosis of bursitis, etc.Diagnosis of bursitis, etc.– Musculotendinous or joint pain Musculotendinous or joint pain

(controversial use)(controversial use)

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Local AnestheticsLocal Anesthetics

When compared to general When compared to general anesthetics, use of local anesthetic anesthetics, use of local anesthetic allows for a more rapid recovery and allows for a more rapid recovery and there are few, if any, residual effects, there are few, if any, residual effects, such as lethargy or confusion.such as lethargy or confusion.

Local anesthetic activity will be Local anesthetic activity will be effective due to infiltration of the effective due to infiltration of the target tissues.target tissues.

Epinephrine is often added to local Epinephrine is often added to local anesthetics to provide a longer anesthetics to provide a longer duration of action.duration of action.

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Local Anesthetics Local Anesthetics ((cont.cont.))

Epinephrine is a local Epinephrine is a local vasoconstrictor, which diminishes vasoconstrictor, which diminishes blood flow and reduces absorption of blood flow and reduces absorption of the anesthetic. the anesthetic.

If the concentration is appropriate it If the concentration is appropriate it will begin to affect the outer fibers of will begin to affect the outer fibers of the nearest peripheral nerves the nearest peripheral nerves followed by the inner part of the followed by the inner part of the nerve.nerve.

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Local Anesthetics Local Anesthetics ((cont.cont.)) Drug metabolism by the body will Drug metabolism by the body will

diminish the effects of the anesthetic.diminish the effects of the anesthetic.– Dental procedure, return of motor then Dental procedure, return of motor then

sensation.sensation. Depending on the type of anesthetic Depending on the type of anesthetic

used, this entire process can take used, this entire process can take from minutes to hours to fully from minutes to hours to fully complete.complete.

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Delivery and Use of Local Delivery and Use of Local AnestheticsAnesthetics InjectableInjectable Topical (transdermal delivery)Topical (transdermal delivery)

– Not as effective as injected Not as effective as injected Peripheral nerve blockPeripheral nerve block

– Injected close to a nerve trunk to block afferent Injected close to a nerve trunk to block afferent transmission in minor surgical procedures, transmission in minor surgical procedures, tooth extraction, or in relieving chronic pain tooth extraction, or in relieving chronic pain conditionsconditions

Central nerve blockCentral nerve block– More serious conditionsMore serious conditions

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Commonly Used Local Commonly Used Local AnestheticsAnesthetics

Table 10-6, pg 142Table 10-6, pg 142 Procaine (Novocain)Procaine (Novocain)

– First widely used injectableFirst widely used injectable– In the mid 20th century, other local anesthetics were In the mid 20th century, other local anesthetics were

produced that have better anesthetic properties. produced that have better anesthetic properties. However, the term “Novocain” is still sometimes However, the term “Novocain” is still sometimes used by the lay public as the description for a local used by the lay public as the description for a local anestheticanesthetic. .

CocaineCocaine– Used in some nasal surgeries in a controlled surgical Used in some nasal surgeries in a controlled surgical

setting as a local anesthetic with vasoconstricting setting as a local anesthetic with vasoconstricting properties. properties.

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Physician Use Physician Use ConsiderationsConsiderations

There are three main There are three main considerations when a physician considerations when a physician uses a local anesthetic: uses a local anesthetic: – Time to effect Time to effect – Length of time the anesthetic is Length of time the anesthetic is

effectiveeffective– Adverse effectsAdverse effects

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Adverse Effects of Local Adverse Effects of Local AnestheticsAnesthetics

Local anesthetics can have serious Local anesthetics can have serious and toxic effects if used in excessive and toxic effects if used in excessive dosagesdosages

There is a rare possibility of an There is a rare possibility of an overdoseoverdose

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Adverse Effects of Local Adverse Effects of Local Anesthetics (Anesthetics (cont.cont.))

Altered CNS activity, including both Altered CNS activity, including both excitation and depression.excitation and depression.

– The signs of CNS excitation can include The signs of CNS excitation can include confusion, agitation, generalized confusion, agitation, generalized excitation, and seizures.excitation, and seizures.

– CNS depression can be exhibited by CNS depression can be exhibited by decreased respiration.decreased respiration.

Other possible side effects include Other possible side effects include allergic reactions and cardiac arrest, allergic reactions and cardiac arrest, sometimes leading to death.sometimes leading to death.

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What to Tell the What to Tell the AthleteAthlete Pg 143 Pg 143