AnalgesicsAnalgesics

Adapted from L. SchefflerAdapted from L. Scheffler

AnalgesicsAnalgesics

Analgesics are common pain relievers.Analgesics are common pain relievers.

Many analgesics also have antipyretic Many analgesics also have antipyretic properties as well. They can be used to properties as well. They can be used to reduce feverreduce fever

Some analgesics are also anti-Some analgesics are also anti-inflammatory drugs as wellinflammatory drugs as well

Classification of AnalgesicsClassification of Analgesics

Aspirin Heroin

Codeine

OpiumIbuprofen

Acetaminophen

MildAnalgesics

StrongAnalgesics

Analgesics

Mild AnalgesicsMild Analgesics

Mild Analgesics include Mild Analgesics include over-the-counter pain over-the-counter pain relievers and fever relievers and fever depressants.depressants.

Examples of mild Examples of mild analgesics include analgesics include Aspirin, acetaminophen, Aspirin, acetaminophen, and ibuprofenand ibuprofen

AspirinAspirin

AspirinAspirin is a derivative of is a derivative of salicyclic acidsalicyclic acidSalicyclic acidSalicyclic acid was was found in the bark of the found in the bark of the willow tree and was willow tree and was used as a pain reliever used as a pain reliever and as a way to relieve and as a way to relieve fever symptoms of fever symptoms of malariamalaria

Salicyclic Acid

Aspirin

AspirinAspirin

In 1899, Felix Hoffman, a chemist from the In 1899, Felix Hoffman, a chemist from the Bayer Company, developed a low-cost Bayer Company, developed a low-cost process to synthesize an ethanoate ester process to synthesize an ethanoate ester of salicyclic acid, called of salicyclic acid, called aspirinaspirinIn the synthesis of Aspirin, the ethanoic In the synthesis of Aspirin, the ethanoic acid forms an ester with the alcohol group acid forms an ester with the alcohol group on the second carbonon the second carbon

AspirinAspirinAspirin is believed to Aspirin is believed to inhibit the enzyme, inhibit the enzyme, Prostaglandin synthase Prostaglandin synthase which is formed at the site which is formed at the site of an injury.of an injury.This inhibits the This inhibits the production of production of prostaglandins which prostaglandins which produce fever and produce fever and swelling as well as swelling as well as transmitting pain signals transmitting pain signals to the brain.to the brain.

AspirinAspirinAspirin is able to reduce pain and fevers Aspirin is able to reduce pain and fevers and dilate blood vesselsand dilate blood vesselsAspirin enlarges blood vessels which Aspirin enlarges blood vessels which helps prevent blood clots. helps prevent blood clots. This vasodilation of the surface blood This vasodilation of the surface blood vessels also allows an increase of heat vessels also allows an increase of heat released which lowers the temperature of released which lowers the temperature of a fevera feverAspirin is also taken to prevent Aspirin is also taken to prevent recurring heart attacksrecurring heart attacksIt may also be effective in It may also be effective in preventing prostrate cancerpreventing prostrate cancer

Side Effects of AspirinSide Effects of AspirinAspirin can irritate the stomach lining which may Aspirin can irritate the stomach lining which may lead to ulcerslead to ulcers

If aspirin is used over long periods of time, it may If aspirin is used over long periods of time, it may lead to problems with blood clottinglead to problems with blood clotting

An overdose on aspirin, such as the case with An overdose on aspirin, such as the case with some arthritis sufferers, may lead to dizziness, some arthritis sufferers, may lead to dizziness, ringing in the ears, gastrointestinal problems, ringing in the ears, gastrointestinal problems, mental confusion, and bleeding.mental confusion, and bleeding.

Some people are allergic to aspirin leading to Some people are allergic to aspirin leading to bronchial asthmabronchial asthma

In children under 12 Aspirin has been linked to In children under 12 Aspirin has been linked to Reye’s syndromeReye’s syndrome

Other Mild AnalgesicsOther Mild Analgesics

Acetaminophen (Paracetamol)Acetaminophen (Paracetamol)

– Commonly sold as TylenolCommonly sold as Tylenol

IbuprofenIbuprofen

– Commonly sold under the name AdvilCommonly sold under the name Advil

AcetaminophenAcetaminophen

Acetaminophen is a pain Acetaminophen is a pain reducer, such as Tylenol but reducer, such as Tylenol but does not reduce inflammationdoes not reduce inflammationWhen taken at recommended When taken at recommended doses, it has negligible side doses, it has negligible side effectseffectsIt’s low level side effects make it It’s low level side effects make it favorable to arthritis patients favorable to arthritis patients and childrenand childrenOveruse and overdoses can lead Overuse and overdoses can lead to acute liver failure and kidney to acute liver failure and kidney damagedamage

IbuprofenIbuprofen

Ibuprofen is a more Ibuprofen is a more powerful pain reliever powerful pain reliever than aspirin in high than aspirin in high doses, but is inferior doses, but is inferior for anti-inflammationfor anti-inflammationSide effects include Side effects include gastrointestinal bleeding and gastrointestinal bleeding and irritationirritationCan aggravate kidney Can aggravate kidney problemsproblems

Strong AnalgesicsStrong Analgesics

Only Available by prescriptionOnly Available by prescription

Used to relieve Used to relieve severesevere pain associated pain associated with injuries, heart attacks, or chronic with injuries, heart attacks, or chronic diseases such as cancerdiseases such as cancer

Most strong analgesics are derived from Most strong analgesics are derived from the opium poppy or synthetically producedthe opium poppy or synthetically produced

Basically three types: Natural, Basically three types: Natural, semi-synthetic, and syntheticsemi-synthetic, and synthetic

MorphineMorphineNaturally occurring in Naturally occurring in the poppy- Only the poppy- Only needs to be isolatedneeds to be isolatedVery strong pain Very strong pain reliever but also very reliever but also very addictive (2addictive (2ndnd to to Heroin)Heroin)Usually injected but Usually injected but can be smoked, can be smoked, sniffed or swallowedsniffed or swallowedCommonly used in Commonly used in hospitalshospitalsLarge illegal street Large illegal street cultureculture

CodeineCodeine Most commonly used Most commonly used strong analgesicstrong analgesicSimilar to Morphine Similar to Morphine except for the except for the replacement of a replacement of a (OH-) group for (OH-) group for (OCH(OCH33) group) groupCommonly used with Commonly used with Tylenol as a more mild Tylenol as a more mild analgesicanalgesic1/6 as strong as 1/6 as strong as Morphine and less Morphine and less addictiveaddictive

HeroinHeroinOriginally sold as cough suppressant and pain Originally sold as cough suppressant and pain killer10 times stronger than Morphinekiller10 times stronger than MorphineIncredibly addictive (many times, other strong Incredibly addictive (many times, other strong analgesics are needed for withdrawal)analgesics are needed for withdrawal)

HeroinHeroinSynthesized from Synthesized from morphine in a morphine in a esterification reaction esterification reaction with acetyl chloridewith acetyl chloride

It is absorbed by the It is absorbed by the brain very quickly brain very quickly resulting in a potent highresulting in a potent high

Many other problems are Many other problems are associated with heroin associated with heroin addiction including as addiction including as prostitution and AIDS.prostitution and AIDS.

Other Synthetic Strong Other Synthetic Strong AnalgesicsAnalgesics

VicodinVicodinIs solution of Is solution of acetaminophen and acetaminophen and hydrocodone (the latter hydrocodone (the latter being the stronger)being the stronger)

Hydrocodone is addictive Hydrocodone is addictive and can cause highs.and can cause highs.

Usually taken orallyUsually taken orally

Stronger than codeine but Stronger than codeine but not as strong than not as strong than MorphineMorphine

Synthetic Strong AnalgesicsSynthetic Strong Analgesics (Opioids)(Opioids)

The active area of The active area of morphine has been morphine has been identified and can be identified and can be synthesized.synthesized.This has produced This has produced many synthetic many synthetic analgesics and has analgesics and has allowed scientists to allowed scientists to eliminate some of the eliminate some of the harmful side effects harmful side effects of more natural of more natural analgesics.analgesics.

DemerolDemerol

Demerol (Meperidine)Demerol (Meperidine)

Used for moderate to Used for moderate to severe pain and to severe pain and to stop muscle spasms.stop muscle spasms.

Usually injected or Usually injected or taken orally.taken orally.

MethadoneMethadoneCompared to most Compared to most strong analgesics it is strong analgesics it is weaker.weaker.Has been synthesized Has been synthesized to not have euphoric to not have euphoric properties and mild properties and mild withdrawal effects but withdrawal effects but is still addictive.is still addictive.Used as an analgesic Used as an analgesic but most commonly to but most commonly to help in the withdrawal help in the withdrawal for Heroin addicts.for Heroin addicts.

Mechanism of Strong AnalgesicsMechanism of Strong Analgesics

The human body contains “natural The human body contains “natural opiates” in the brain called endorphinsopiates” in the brain called endorphins

These are produced in the body during These are produced in the body during extreme conditions such as “running high” extreme conditions such as “running high” and extreme injuries.and extreme injuries.

When these are absorbed by receptors in When these are absorbed by receptors in the brain the body feels analgesia and the the brain the body feels analgesia and the pain is reduced.pain is reduced.

Mechanism of Strong Analgesics contMechanism of Strong Analgesics cont..

Opiates derived from the poppy act in the same Opiates derived from the poppy act in the same way as endorphins but are not natural to the way as endorphins but are not natural to the human body.human body.The “high” is produced because of the The “high” is produced because of the absorption of opiates is quicker than endorphinsabsorption of opiates is quicker than endorphinsDrugs such as naloxone act to fill the receptors Drugs such as naloxone act to fill the receptors in the brain but are not analgesics and thus are in the brain but are not analgesics and thus are used to prevent overdoses on analgesics.used to prevent overdoses on analgesics.Endorphins are not used as analgesics because Endorphins are not used as analgesics because the cannot be stored and are unstable.the cannot be stored and are unstable.

Side Effects of Strong AnalgesicsSide Effects of Strong AnalgesicsShort termShort term

Dulling of PainDulling of PainEuphoriaEuphoriaSlow Nervous system Slow Nervous system Slowed heart rateSlowed heart rateLoss of cough reflexLoss of cough reflexNauseaNauseaOverdoses can lead Overdoses can lead to deathto deathPossibility of strokePossibility of strokeOverall slowdown of Overall slowdown of biological systemsbiological systems

Long TermLong TermAddiction and very strong Addiction and very strong withdrawal effectswithdrawal effectsConstipationConstipationLoss of libidoLoss of libidoDisruptions in menstruationDisruptions in menstruation““Cross-tolerance”Cross-tolerance”Loss of appetiteLoss of appetiteProblems associated with Problems associated with buying street drugs i.e. buying street drugs i.e. sharing needles AIDS and sharing needles AIDS and prostitution.prostitution.

Local Anesthetics -- CocaineLocal Anesthetics -- Cocaine

Cocaine used in Cocaine used in 1885 as a local 1885 as a local anesthetic.anesthetic.Extracted from the Extracted from the plant plant Erythoxylum Erythoxylum cocococo

([1R-(exo,exo)]-3-(Benzoyloxy)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylic acid methyl ester

History of CocaineHistory of CocaineCoca leaves have been chewed by South American Coca leaves have been chewed by South American Indians for thousands of years. There were used to Indians for thousands of years. There were used to induce feelings of euphoriainduce feelings of euphoria

Was banned by Spanish settlers in the 1500s but the Was banned by Spanish settlers in the 1500s but the ban was repealed when it became apparent that slaves ban was repealed when it became apparent that slaves worked harder while on itworked harder while on it

United States cocaine was used in soft drinks until it was classified as narcotic in 1914

Clinically used as a local anaesthetic for eye operations and in modified synthetic forms for dental treatment (novocaine) and sore throats (benzocaine)

CocaineCocaine

The leaves of the coca plant The leaves of the coca plant contain 0.6% - 1.8% contain 0.6% - 1.8% alkaloidal cocainealkaloidal cocaineTo extract, cocaine To extract, cocaine leaves are soaked in leaves are soaked in kerosene and sulfuric kerosene and sulfuric acidacidHCl is added creating HCl is added creating cocaine hydrochloride, which can be extracted as powdery flakes or rocks

Clinical ActionClinical ActionActs as a Acts as a reuptake blocker for the monoamines dopamine, norepinephrine and serotonin

interacts with serotonin and muscarinic acetylcholine receptors and the sodium channels

influence on the axonal voltage-gated sodium channels that provides cocaine's local anaesthetic properties

Effects of CocaineEffects of CocaineSubjectiveSubjective

Euphoria Increased sociability Increased energy Hyper vigilance

Physiological

Increased heart rate Increased respiration rate Increased body temperature Increased blood pressure Pupil dilation

Derivatives of CocaineDerivatives of Cocaine

Cocaine is too addictive and in Cocaine is too addictive and in appropriate for medicinal useappropriate for medicinal use

Two derivatives of cocaine are widely Two derivatives of cocaine are widely used as local anestheticsused as local anesthetics

– Procaine or NovacaineProcaine or Novacaine– LidocaineLidocaine

Procaine (Novacaine)Procaine (Novacaine)

Principal use in dentistry for temporary numbing Principal use in dentistry for temporary numbing of mouth areaof mouth areaFirst synthesized in 1905 and was the first injectable man-made local anesthetic

Restricts blood vessels, reducing bleeding

Novacaine

LidocaineLidocaine

First modern local anesthetic agent

Sodium channel blockerSodium channel blockerAdministered parenterally for ventricular arrhythmias, subcutaneously for minor surgical procedures, and topically to mucosal surfaces prior to invasive procedures

Lidocaine