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Cocaine Facts
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Whatiscocaine?
Cocaineisapowerfullyaddictivestimulantdrug.Forthousandsofyears,
peopleinSouthAmericahavechewedandingestedcocaleaves(Erythroxylon
coca),thesourceofcocaine,fortheirstimulanteffects. Thepurifiedchemical,
cocainehydrochloride,wasisolatedfromtheplantmorethan100yearsago.In
theearly1900s,purifiedcocainewasthemainactiveingredientinmanytonics
andelixirsdevelopedtotreatawidevarietyofillnessesandwasevenan
ingredientintheearlyformulationsofCoca-Cola .Beforethedevelopmentof
syntheticlocalanesthetic,surgeonsusedcocainetoblockpain. However,
researchhassinceshownthatcocaineisapowerfullyaddictivesubstancethat
canalterbrainstructureandfunctionifusedrepeatedly.
Today,cocaineisaScheduleIIdrug,whichmeansthatithashighpotentialfor
abusebutcanbeadministeredbyadoctorforlegitimatemedicaluses,suchas
localanesthesiaforsomeeye,ear,andthroatsurgeries.Asastreetdrug,
cocaineappearsasafine,white,crystallinepowderandisalsoknownasCoke,
C,Snow,Powder,orBlow.Streetdealersoftendilute(or“cut”)itwithnon-
psychoactivesubstancessuchascornstarch,talcumpowder,flour,orbaking
sodatoincreasetheirprofits.Theymayalsoadulteratecocainewithotherdrugs
likeprocaine(achemicallyrelatedlocalanesthetic)oramphetamine(another
psychoactivestimulant). Someuserscombinecocainewithheroin—calleda
Speedball.
Photoby©iStock.com/RafalCichawa
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Peopleabusetwochemicalformsofcocaine:thewater-solublehydrochloride
saltandthewater-insolublecocainebase(orfreebase).Usersinjectorsnort
thehydrochloridesalt,whichisapowder.Thebaseformofcocaineiscreated
byprocessingthedrugwithammoniaorsodiumbicarbonate(bakingsoda)and
water,thenheatingittoremovethehydrochloridetoproduceasmokable
substance.Thetermcrack,whichisthestreetnamegiventofreebasecocaine,
referstothecracklingsoundheardwhenthemixtureissmoked.2
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Whatisthescopeofcocaineusein
theUnitedStates?
AccordingtotheNationalSurveyonDrugUseandHealth(NSDUH),cocaine
usehasremainedrelativelystablesince2009.In2014,therewerean
estimated1.5millioncurrent(past-month)cocaineusersaged12orolder(0.6
percentofthepopulation).Adultsaged18to25yearshaveahigherrateof
currentcocaineusethananyotheragegroup,with1.4percentofyoungadults
reportingpast-monthcocaineuse.
The2015MonitoringtheFuturesurvey,whichannuallysurveysteenattitudes
anddruguse,reportsasignificantdeclinein30-dayprevalenceofpowder
cocaineuseamong8th,10th,and12thgradersfrompeakuseinthelate1990s.
In2014,1.1percentof12thgradersandonly0.8percentof10thandhalfa
percentof8thgradersreportedusingcocaineinthepastmonth.
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Source:UniversityofMichigan,MonitoringtheFuturenationalresultsondruguse:1975-
2015:overview,keyfindingsonadolescentdruguse,2016.
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Repeatedcocaineusecanproduceaddictionandotheradversehealth
consequences.In2014,accordingtotheNSDUH,about913,000Americans
mettheDiagnosticandStatisticalManualofMentalDisorderscriteriafor
dependenceorabuseofcocaine(inanyform)duringthepast12months.
Further,datafromthe2011DrugAbuseWarningNetwork(DAWN)report
showedthatcocainewasinvolvedin505,224ofthenearly1.3millionvisitsto
emergencydepartmentsfordrugmisuseorabuse.Thistranslatestooveronein
threedrugmisuseorabuse-relatedemergencydepartmentvisits(40percent)
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Howiscocaineused?
Usersprimarilyadministercocaineorally,intranasally,intravenously,orby
inhalation.Whenpeoplesnortthedrug(intranasaluse),theyinhalecocaine
powderthroughthenostrils,whereitisabsorbedintothebloodstreamthrough
thenasaltissues.Usersalsomayrubthedrugontotheirgums(oraluse).
Dissolvingcocaineinwaterandinjectingit(intravenoususe)releasesthedrug
directlyintothebloodstreamandheightenstheintensityofitseffects.When
peoplesmokecocaine(inhalation),theyinhaleitsvapororsmokeintothe
lungs,whereabsorptionintothebloodstreamisalmostasrapidasbyinjection.
Thisfasteuphoriceffectisoneofthereasonsthatcrackbecameenormously
popularinthemid-1980s.
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Cocaine
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Cocaineuserangesfromoccasionaltorepeatedorcompulsiveuse,witha
varietyofpatternsbetweentheseextremes.Anyrouteofadministrationcan
potentiallyleadtoabsorptionoftoxicamountsofcocaine,causingheartattacks,
strokes,orseizures—allofwhichcanresultinsuddendeath.
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Howdoescocaineproduceits
effects?
Thebrain’smesolimbicdopaminesystem,itsrewardpathway,isstimulatedby
alltypesofreinforcingstimuli,suchasfood,sex,andmanydrugsofabuse,
includingcocaine. Thispathwayoriginatesinaregionofthemidbraincalled
theventraltegmentalareaandextendstothenucleusaccumbens,oneofthe
brain’skeyrewardareas. Besidesreward,thiscircuitalsoregulatesemotions
andmotivation.
Inthenormalcommunicationprocess,dopamineisreleasedbyaneuroninto
thesynapse(thesmallgapbetweentwoneurons),whereitbindstospecialized
proteinscalleddopaminereceptorsontheneighboringneuron.Bythisprocess,
dopamineactsasachemicalmessenger,carryingasignalfromneuronto
neuron.Anotherspecializedproteincalledatransporterremovesdopamine
fromthesynapsetoberecycledforfurtheruse.
Drugsofabusecaninterferewiththisnormalcommunicationprocess.For
example,cocaineactsbybindingtothedopaminetransporter,blockingthe
removalofdopaminefromthesynapse.Dopaminethenaccumulatesinthe
synapsetoproduceanamplifiedsignaltothereceivingneurons.Thisiswhat
causestheeuphoriacommonlyexperiencedimmediatelyaftertakingthedrug
(seethevideo"BrainReward:UnderstandingHowtheBrainRespondsto
NaturalRewardsandDrugsofAbuse").
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ImagebyNIDA
Cocaineinthebrain:Inthenormalneuralcommunicationprocess,dopamineis
releasedbyaneuronintothesynapse,whereitcanbindtodopaminereceptorson
neighboringneurons.Normally,dopamineisthenrecycledbackintothetransmitting
neuronbyaspecializedproteincalledthedopaminetransporter.Ifcocaineispresent,
itattachestothedopaminetransporterandblocksthenormalrecyclingprocess,
resultinginabuildupofdopamineinthesynapse,whichcontributestothepleasurable
effectsofcocaine.
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Whataresomewaysthatcocaine
changesthebrain?
Useofcocaine,likeotherdrugsofabuse,induceslong-termchangesinthe
brain.Animalstudiesshowthatcocaineexposurecancausesignificant
neuroadaptationsinneuronsthatreleasetheexcitatoryneurotransmitter
glutamate. Animalschronicallyexposedtococainedemonstrateprofound
changesinglutamateneurotransmission—includinghowmuchisreleasedand
thelevelofreceptorproteins—intherewardpathway,particularlythenucleus
accumbens.Theglutamatesystemmaybeanopportunetargetforanti-
addictionmedicationdevelopment,withthegoalofreversingthecocaine-
inducedneuroadaptationsthatcontributetothedrivetousethedrug.
Althoughaddictionresearchershavefocusedonadaptationsinthebrain’s
rewardsystem,drugsalsoaffectthebrainpathwaysthatrespondtostress.
Stresscancontributetococainerelapse,andcocaineusedisordersfrequently
co-occurwithstress-relateddisorders. Thestresscircuitsofthebrainare
distinctfromtherewardpathway,butresearchindicatesthatthereareimportant
waysthattheyoverlap.Theventraltegmentalareaseemstoactasacritical
integrationsiteinthebrainthatrelaysinformationaboutbothstressanddrug
cuestootherareasofthebrain,includingonesthatdrivecocaineseeking.
Animalsthathavereceivedcocainerepeatedlyaremorelikelytoseekthedrug
inresponsetostress,andthemoreofthedrugtheyhavetaken,themorestress
affectsthisbehavior. Researchsuggeststhatcocaineelevatesstress
hormones,inducingneuroadaptationsthatfurtherincreasesensitivitytothe
drugandcuesassociatedwithit.
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Chroniccocaineexposureaffectsmanyotherareasofthebraintoo.For
example,animalresearchindicatesthatcocainediminishesfunctioninginthe
orbitofrontalcortex(OFC),whichappearstounderliethepoordecision-making,
inabilitytoadapttonegativeconsequencesofdruguse,andlackofself-insight
shownbypeopleaddictedtococaine. Astudyusingoptogenetictechnology,
whichuseslighttoactivatespecific,genetically-modifiedneurons,foundthat
stimulatingtheOFCrestoresadaptivelearninginanimals.Thisintriguingresult
suggeststhatstrengtheningOFCactivitymaybeagoodtherapeuticapproach
toimproveinsightandawarenessoftheconsequencesofdruguseamong
peopleaddictedtococaine.
Brainimagesshowingdecreasedglucosemetabolism,whichindicatesreduced
activity,intheorbitofrontalcortex(OFC)inacontrolsubject(left)andacocaine-
addictedsubject(right).
VolkowND,WantG-J,FowlerJS,TomasiD,TelandF.Addiction:beyonddopamine
rewardcircuitry.ProcNatlAcadSciUSA.2011;108(37):15037-15042.
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Whataretheshort-termeffectsof
cocaineuse?
Cocaine’seffectsappearalmostimmediatelyafterasingledoseanddisappear
withinafewminutestoanhour.Smallamountsofcocaineusuallymakethe
userfeeleuphoric,energetic,talkative,mentallyalert,andhypersensitiveto
sight,sound,andtouch.Thedrugcanalsotemporarilydecreasetheneedfor
foodandsleep. Someusersfindthatcocainehelpsthemperformsimple
physicalandintellectualtasksmorequickly,althoughothersexperiencethe
oppositeeffect.
Thedurationofcocaine’seuphoriceffectsdependupontherouteof
administration.Thefasterthedrugisabsorbed,themoreintensetheresulting
high,butalsotheshorteritsduration.Snortingcocaineproducesarelatively
slowonsetofthehigh,butitmaylastfrom15to30minutes.Incontrast,thehigh
fromsmokingismoreimmediatebutmaylastonly5to10minutes.
Short-termphysiologicaleffectsofcocaineuseincludeconstrictedblood
vessels;dilatedpupils;andincreasedbodytemperature,heartrate,andblood
pressure. Largeamountsofcocainemayintensifytheuser’shighbutcanalso
leadtobizarre,erratic,andviolentbehavior.Somecocaineusersreport
feelingsofrestlessness,irritability,anxiety,panic,andparanoia. Usersmay
alsoexperiencetremors,vertigo,andmuscletwitches.
Severemedicalcomplicationscanoccurwithcocaineuse.Someofthemost
frequentarecardiovasculareffects,includingdisturbancesinheartrhythmand
heartattacks;neurologicaleffects,includingheadaches,seizures,strokes,and
coma;andgastrointestinalcomplications,includingabdominalpainand
nausea. Inrareinstances,suddendeathcanoccuronthefirstuseofcocaine
orunexpectedlythereafter.Cocaine-relateddeathsareoftenaresultofcardiac
arrestorseizures (see"NationalOverdoseDeaths:NumberofDeathsfrom
Cocaine").Manycocaineusersalsousealcohol,andthiscombinationcanbe
particularlydangerous.Thetwosubstancesreacttoproducecocaethylene,
whichmaypotentiatethetoxiceffectsofcocaineandalcoholontheheart. The
combinationofcocaineandheroinisalsoverydangerous.Userscombine
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thesedrugsbecausethestimulatingeffectsofcocaineareoffsetbythesedating
effectsofheroin;however,thiscanleadtotakingahighdoseofheroinwithout
initiallyrealizingit.Becausecocaine'seffectswearoffsooner,thiscanleadtoa
heroinoverdose,inwhichtheuser'srespirationdangerouslyslowsdownor
stops,possiblyfatally.
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Whatarethelong-termeffectsof
cocaineuse?
Withrepeatedexposuretococaine,thebrainstartstoadaptsothatthereward
pathwaybecomeslesssensitivetonaturalreinforcers (see"WhatAreSome
WaysthatCocaineChangestheBrain?").Atthesametime,circuitsinvolvedin
stressbecomeincreasinglysensitive,leadingtoincreaseddispleasureand
negativemoodswhennottakingthedrug,whicharesignsofwithdrawal.These
combinedeffectsmaketheusermorelikelytofocusonseekingthedrug
insteadofrelationships,food,orothernaturalrewards.
Withregularuse,tolerancemaydevelopsothathigherdoses,morefrequent
useofcocaine,orbothareneededtoproducethesamelevelofpleasureand
relieffromwithdrawalexperiencedinitially. Atthesametime,userscanalso
developsensitization,inwhichlesscocaineisneededtoproduceanxiety,
convulsions,orothertoxiceffects. Tolerancetococainerewardand
sensitizationtococainetoxicitycanincreasetheriskofoverdoseina
regularuser.
Userstakecocaineinbinges,inwhichcocaineisusedrepeatedlyandat
increasinglyhigherdoses.Thiscanleadtoincreasedirritability,restlessness,
panicattacks,paranoia,andevenafull-blownpsychosis,inwhichthe
individuallosestouchwithrealityandexperiencesauditoryhallucinations.
Withincreasingdosesorhigherfrequencyofuse,theriskofadverse
psychologicalorphysiologicaleffectsincreases. Animalresearchsuggests
thatbingingoncocaineduringadolescenceenhancessensitivitytothe
rewardingeffectsofcocaineandMDMA(EcstasyorMolly). Thus,bingeuseof
cocaineduringadolescencemayfurtherincreasevulnerabilitytocontinueduse
ofthedrugamongsomepeople.
Specificroutesofcocaineadministrationcanproducetheirownadverseeffects.
Regularlysnortingcocainecanleadtolossofsenseofsmell,nosebleeds,
problemswithswallowing,hoarseness,andanoverallirritationofthenasal
septumleadingtoachronicallyinflamed,runnynose. Smokingcrackcocaine
damagesthelungsandcanworsenasthma. Peoplewhoinjectcocainehave
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puncturemarkscalledtracks,mostcommonlyintheirforearms, andtheyareat
riskofcontractinginfectiousdiseaseslikeHIVandhepatitisC(see"WhyAre
CocaineUsersatRiskforContractingHIVandHepatitis?").Theyalsomay
experienceallergicreactions,eithertothedrugitselfortoadditivesinstreet
cocaine,whichinseverecasescanresultindeath.
Cocainedamagesmanyotherorgansinthebody.Itreducesbloodflowinthe
gastrointestinaltract,whichcanleadtotearsandulcerations. Manychronic
cocaineuserslosetheirappetiteandexperiencesignificantweightloss
andmalnourishment.Cocainehassignificantandwell-recognizedtoxiceffects
ontheheartandcardiovascularsystem. Chestpainthatfeelslikeaheart
attackiscommonandsendsmanycocaineuserstotheemergencyroom.
Cocaineuseislinkedwithincreasedriskofstroke, aswellasinflammationof
theheartmuscle,deteriorationoftheabilityofthehearttocontract,andaortic
ruptures.
Inadditiontotheincreasedriskforstrokeandseizures,otherneurological
problemscanoccurwithlong-termcocaineuse. Therehavebeenreportsof
intracerebralhemorrhage,orbleedingwithinthebrain,andballoon-likebulges
inthewallsofcerebralbloodvessels. Movementdisorders,including
Parkinson’sdisease,mayalsooccuraftermanyyearsofcocaineuse.
Generally,studiessuggestthatawiderangeofcognitivefunctionsareimpaired
withlong-termcocaineuse—suchassustainingattention,impulseinhibition,
memory,makingdecisionsinvolvingrewardsorpunishments,andperforming
motortasks.
Formercocaineusersareathighriskforrelapse,evenfollowinglongperiodsof
abstinence.Researchindicatesthatduringperiodsofabstinence,thememory
ofthecocaineexperienceorexposuretocuesassociatedwithdrugusecan
triggerstrongcravings,whichcanleadtorelapse.
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Whyarecocaineusersatriskfor
contractingHIV/AIDSandhepatitis?
Drugintoxicationandaddictioncancompromisejudgmentanddecision-
makingandpotentiallyleadtoriskysexualbehavior,includingtradingsexfor
drugs,andneedlesharing.Thisincreasesacocaineuser’sriskforcontracting
infectiousdiseasessuchasHIVandhepatitisC(HCV). Therearenovaccines
topreventHIVorHCVinfections.
StudiesthatexaminepatternsofHIVinfectionandprogressionhave
demonstratedthatcocaineuseacceleratesHIVinfection. Researchindicates
thatcocaineimpairsimmunecellfunction, promotesreplicationoftheHIV
virus,andpotentiatesthedamagingeffectsofHIVondifferenttypesofcellsin
thebrainandspinalcord,resultinginfurtherdamage. Studiesalsosuggest
thatcocaineuseacceleratesthedevelopmentofNeuroAIDS,neurological
conditionsassociatedwithHIVinfection.SymptomsofNeuroAIDSinclude
memoryloss,movementproblems,andvisionimpairment.
CocaineuserswithHIVoftenhaveadvancedprogressionofthedisease,with
increasedviralloadandaccelerateddecreasesinCD4+cellcounts.Infection
withHIVincreasesriskforco-infectionwithHCV,avirusthataffectstheliver.
Co-infectioncanleadtoseriousillnesses—includingproblemswiththeimmune
systemandneurologicconditions.Livercomplicationsareverycommon,with
manyco-infectedindividualsdyingofchronicliverdiseaseandcancer.
AlthoughthelinkbetweeninjectiondruguseandHIV/HCViswellestablished,
morestudiesareneededtounderstandthemolecularmechanismsunderlying
thisincreasedriskofco-infectioninnon-injectingsubstanceusers.
Theinteractionofsubstanceuse,HIV,andhepatitismayacceleratedisease
progression.Forexample,HIVspeedsthecourseofHCVinfectionby
acceleratingtheprogressionofhepatitis-associatedliverdisease. Research
haslinkedHIV/HCVco-infectionwithincreasedmortalitywhencompared
toeitherinfectionalone. Substanceuseandco-infectionlikelynegatively
influenceHIVdiseaseprogressionandtheabilityofthebodytomarshalan
immuneresponse.
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PatientswithHIV/HCVco-infectioncanbenefitfromsubstanceabusetreatment
andantiretroviraltherapies,whencloselymonitored. Antiretroviraltreatment
isnoteffectiveforeveryoneandcanhavesignificantsideeffects,necessitating
closemedicalsupervision.TestingforHIVandHCVisrecommendedforany
individualwhohaseverinjecteddrugs,sincethediseaseishighly
transmissibleviainjection.
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Whataretheeffectsofmaternal
cocaineuse?
Mostwomenwhoareaddictedtococaineareofchildbearingage.Estimates
suggestthatabout5percentofpregnantwomenuseoneormoreaddictive
substances, andtherearearound750,000cocaine-exposedpregnancies
everyyear. Althoughwomenmaybereluctanttoreportsubstanceuse
patternsbecauseofsocialstigmaandfearoflosingcustodyoftheirchildren,
theyshouldbeawarethatdrugusewhilepregnantisassociatedwithspecific
risksthatmaybereducedwithappropriatecare.
Cocaineuseduringpregnancyisassociatedwithmaternalmigrainesand
seizures,prematuremembranerupture,andseparationoftheplacentallining
fromtheuteruspriortodelivery. Pregnancyisaccompaniedbynormal
cardiovascularchanges,andcocaineuseexacerbatesthese—sometimes
leadingtoseriousproblemswithhighbloodpressure(hypertensivecrises),
spontaneousmiscarriage,pretermlabor,anddifficultdelivery. Cocaine-using
pregnantwomenmustreceiveappropriatemedicalandpsychologicalcare—
includingaddictiontreatment—toreducetheserisks.
Sex-specificaddictiontreatmentandcomprehensiveservices—including
prenatalcare,mentalhealthcounseling,vocational/employmentassistance,
andparentingskillstraining—canpromotedrugabstinenceandotherpositive
healthbehaviors. Motivationalincentives/contingencymanagement(see
"BehavioralInterventions")asanadjuncttootheraddictiontreatmentisa
particularlypromisingstrategytoengagewomeninprenatalcareand
counselingforsubstanceuse.
Itisdifficulttoestimatethefullextentoftheconsequencesofmaternaldruguse
andtodeterminethespecifichazardofaparticulardrugtotheunbornchild.
Thisisbecausemultiplefactors—suchastheamountandnumberofalldrugs
used,includingnicotineoralcohol;extentofprenatalcare;exposuretoviolence
intheenvironment;socioeconomicconditions;maternalnutrition;otherhealth
conditions;andexposuretosexuallytransmitteddiseases—canallinteractto
influencematernalandchildoutcomes. Similarly,parentingstyles,
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qualityofcareduringearlychildhood,exposuretoviolence,andcontinued
parentaldrugusearestrongenvironmentalfactorsinfluencingoutcomes.
Babiesborntomotherswhousecocaineduringpregnancyareoften
prematurelydelivered,havelowbirthweightsandsmallerhead
circumferences,andareshorterinlengththanbabiesborntomotherswhodo
notusecocaine. Direpredictionsofreducedintelligenceandsocialskills
inbabiesborntomotherswhousedcrackcocainewhilepregnantduringthe
1980s—so-called"crackbabies"—weregrosslyexaggerated.However,thefact
thatmostofthesechildrendonotshowseriousovertdeficitsshouldnotbe
overinterpretedtoindicatethatthereisnocauseforconcern.
Usingsophisticatedtechnologies,scientistsarenowfindingthatexposureto
cocaineduringfetaldevelopmentmayleadtosubtle,yetsignificant,later
deficitsinsomechildren. Theseincludebehaviorproblems(e.g.,difficulties
withself-regulation)anddeficitsinsomeaspectsofcognitiveperformance,
informationprocessing,andsustainedattentiontotasks—abilitiesthatare
importantfortherealizationofachild’sfullpotential. Somedeficitspersist
intothelateryears,withprenatallyexposedadolescentsshowingincreasedrisk
forsubtleproblemswithlanguageandmemory. Brainscansinteens
suggeststhatat-restfunctioningofsomebrainregions—includingareas
involvedinattention,planning,andlanguage—maydifferfromthatofnon-
exposedpeers. Moreresearchisneededonthelong-termeffectsofprenatal
cocaineexposure.
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Howiscocaineaddictiontreated?
In2013,cocaineaccountedforalmost6percentofalladmissionstodrugabuse
treatmentprograms.Themajorityofindividuals(68percentin2013)whoseek
treatmentforcocaineusesmokecrackandarelikelytobepolydrugusers,
meaningtheyusemorethanonesubstance. Thosewhoprovidetreatmentfor
cocaineuseshouldrecognizethatdrugaddictionisacomplexdisease
involvingchangesinthebrainaswellasawiderangeofsocial,familial,and
otherenvironmentalfactors;therefore,treatmentofcocaineaddictionmust
addressthisbroadcontextaswellasanyotherco-occurringmentaldisorders
thatrequireadditionalbehavioralorpharmacologicalinterventions.
PharmacologicalApproaches
Presently,therearenomedicationsapprovedbytheU.S.FoodandDrug
Administrationtotreatcocaineaddiction,thoughresearchersareexploringa
varietyofneurobiologicaltargets.Pastresearchhasprimarilyfocusedon
dopamine,butscientistshavealsofoundthatcocaineuseinduceschangesin
thebrainrelatedtootherneurotransmitters—includingserotonin,gamma-
aminobutyricacid(GABA),norepinephrine,andglutamate. Researchersare
currentlytestingmedicationsthatactatthedopamineD receptor,asubtypeof
dopaminereceptorthatisabundantintheemotionandrewardcentersofthe
brain. Otherresearchistestingcompounds(e.g.,N-acetylcysteine)that
restorethebalancebetweenexcitatory(glutamate)andinhibitory(GABA)
neurotransmission,whichisdisruptedbylong-termcocaineuse. Researchin
animalsisalsolookingatmedications(e.g.,lorcaserin)thatactatserotonin
receptors.
Severalmedicationsmarketedforotherdiseasesshowpromiseinreducing
cocaineusewithincontrolledclinicaltrials.Amongthese,disulfiram,whichis
usedtotreatalcoholism,hasshownthemostpromise.Scientistsdonotyet
knowexactlyhowdisulfiramreducescocaineuse,thoughitseffectsmaybe
relatedtoitsabilitytoinhibitanenzymethatconvertsdopamineto
norepinephrine.However,disulfiramdoesnotworkforeveryone.
Pharmacogeneticstudiesarerevealingvariantsinthegenethatencodes
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theDBHenzymeandseemstoinfluencedisulfiram’seffectivenessinreducing
cocaineuse. Knowingapatient’sDBHgenotypecouldhelppredict
whetherdisulfiramwouldbeaneffectivepharmacotherapyforcocaine
dependenceinthatperson.
Finally,researchershavedevelopedandconductedearlytestsonacocaine
vaccinethatcouldhelpreducetheriskofrelapse.Thevaccinestimulatesthe
immunesystemtocreatecocaine-specificantibodiesthatbindtococaine,
preventingitfromgettingintothebrain. Inadditiontoshowingthevaccine’s
safety,aclinicaltrialfoundthatpatientswhoattainedhighantibodylevels
significantlyreducedcocaineuse. However,only38percentofthevaccinated
subjectsattainedsufficientantibodylevelsandforonly2months.
Researchersareworkingtoimprovethecocainevaccinebyenhancingthe
strengthofbindingtococaineanditsabilitytoelicitantibodies. New
vaccinetechnologies,includinggenetransfertoboostthespecificityandlevel
ofantibodiesproducedorenhancethemetabolismofcocaine,mayalso
improvetheeffectivenessofthistreatment. Apharmacogeneticsstudywitha
smallnumberofpatientssuggeststhatindividualswithaparticulargenotype
respondwelltothecocainevaccine—anintriguingfindingthatrequiresmore
research.
Inadditiontotreatmentsforaddiction,researchersaredevelopingmedical
interventionstoaddresstheacuteemergenciesthatresultfromcocaine
overdose.Oneapproachbeingexploredistheuseofgeneticallyengineered
humanenzymesinvolvedinthebreakdownofcocaine,whichwould
counterthebehavioralandtoxiceffectsofacocaineoverdose. Currently,
researchersaretestingandrefiningtheseenzymesinanimalresearch,withthe
ultimategoalofmovingtoclinicaltrials.
BehavioralInterventions
Manybehavioraltreatmentsforcocaineaddictionhaveproventobeeffectivein
bothresidentialandoutpatientsettings.Indeed,behavioraltherapiesareoften
theonlyavailableandeffectivetreatmentsformanydrugproblems,including
stimulantaddictions.However,theintegrationofbehavioraland
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pharmacologicaltreatmentsmayultimatelyprovetobethemosteffective
approach.
Oneformofbehavioraltherapythatisshowingpositiveresultsinpeoplewith
cocaineusedisordersiscontingencymanagement(CM),alsocalled
motivationalincentives.Programsuseavoucherorprize-basedsystemthat
rewardspatientswhoabstainfromcocaineandotherdrugs.Onthebasisof
drug-freeurinetests,thepatientsearnpoints,orchips,whichcanbe
exchangedforitemsthatencouragehealthyliving,suchasagymmembership,
movietickets,ordinneratalocalrestaurant.CMmaybeparticularlyusefulfor
helpingpatientsachieveinitialabstinencefromcocaineandstayin
treatment. Thisapproachhasrecentlybeenshowntobepracticaland
effectiveincommunitytreatmentprograms.
ResearchindicatesthatCMbenefitsdiversepopulationsofcocaineusers.For
example,studiesshowthatcocaine-dependentpregnantwomenandwomen
withyoungchildrenwhoparticipatedinaCMprogramasanadjuncttoother
substanceusedisordertreatmentwereabletostayabstinentlongerthanthose
whoreceivedanequivalentamountofvoucherswithnobehavioral
requirements. PatientsparticipatinginCMtreatmentforcocaineusewhoalso
experiencedpsychiatricsymptoms—suchasdepression,emotionaldistress,
andhostility—showedasignificantreductionintheseproblems,probably
relatedtoreductionsincocaineuse.
Cognitive-behavioraltherapy(CBT)isaneffectiveapproachforpreventing
relapse.Thisapproachhelpspatientsdevelopcriticalskillsthatsupportlong-
termabstinence—includingtheabilitytorecognizethesituationsinwhichthey
aremostlikelytousecocaine,avoidthesesituations,andcopemoreeffectively
witharangeofproblemsassociatedwithdruguse.Thistherapycanalsobe
usedinconjunctionwithothertreatments,therebymaximizingthebenefitsof
both.
Recently,researchersdevelopedacomputerizedformofCBT(CBT4CBT)that
patientsuseinaprivateroomofaclinic. Thisinteractivemultimedia
programcloselyfollowsthekeylessonsandskill-developmentactivitiesofin-
personCBTinaseriesofmodules.Moviespresentexamplesandinformation
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thatsupportthedevelopmentofcopingskills;quizzes,games,andhomework
assignmentsreinforcethelessonsandprovideopportunitiestopractice
skills. StudieshaveshownthataddingCBT4CBTtoweeklycounseling
boostedabstinence andincreasedtreatmentsuccessratesupto6months
aftertreatment.
Therapeuticcommunities(TCs)—drug-freeresidencesinwhichpeoplein
recoveryfromsubstanceusedisordershelpeachothertounderstandand
changetheirbehaviors—canbeaneffectivetreatmentforpeoplewhouse
drugs,includingcocaine. TCsmayrequirea6-to12-monthstayandcan
includeonsitevocationalrehabilitationandothersupportiveservicesthatfocus
onsuccessfulre-integrationoftheindividualintosociety.TCscanalsoprovide
supportinotherimportantareas—improvinglegal,employment,andmental
healthoutcomes.
Regardlessofthespecifictypeofsubstanceusedisordertreatment,itis
importantthatpatientsreceiveservicesthatmatchalloftheirtreatmentneeds.
Forexample,anunemployedpatientwouldbenefitfromvocational
rehabilitationorcareercounselingalongwithaddictiontreatment.Patientswith
maritalproblemsmayneedcouplescounseling.Onceinpatienttreatmentends,
ongoingsupport—alsocalledaftercare—canhelppeopleavoidrelapse.
Researchindicatesthatpeoplewhoarecommittedtoabstinence,engagein
self-helpbehaviors,andbelievethattheyhavetheabilitytorefrainfromusing
cocaine(self-efficacy)aremorelikelytoabstain. Aftercareservestoreinforce
thesetraitsandaddressproblemsthatmayincreasevulnerabilitytorelapse,
includingdepressionanddecliningself-efficacy.
Scientistshavefoundpromisingresultsfromtelephone-basedcounselingasa
low-costmethodtodeliveraftercare.Forexample,peoplewhomisused
stimulantswhoparticipatedinsevensessionsoftelephonecounselingshowed
decreasingdruguseduringthefirst3months,whereasthosewhodidnot
receivecallsincreasedtheiruse. Voucherincentivescanboost
patients'willingnesstoparticipateintelephoneaftercare,doublingthenumber
ofsessionsreceivedaccordingtoonestudy.
Community-basedrecoverygroups—suchasCocaineAnonymous—thatusea
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12-stepprogramcanalsobehelpfulinmaintainingabstinence.Participants
maybenefitfromthesupportivefellowshipandfromsharingwiththose
experiencingcommonproblemsandissues.62
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Howiscutting-edgesciencehelping
usbetterunderstandaddiction?
Twocutting-edgeareasofscience,geneticsandbrainimaging,aresignificantly
advancingourunderstandingofcocaineaddiction.
Researchersestimatethatgeneticscontributes42to79percentoftheriskfor
cocaineuseanddependence. Ofcourse,withacomplexdiseasesuchas
addiction,manydifferentgenesareinvolved,andtheirexpressioncanbe
influencedbytheenvironment.Thereappearstobesignificantoverlapinthe
genesthatputpeopleatriskforalladdictivesubstances,perhapsindicatinga
commonbiologicalpathwayforaddictionregardlessofthedrug.
Ingenome-wideassociationstudies(GWAS),researchersexaminewhether
certaingenevariantsaremorefrequentlyfoundinpeoplewithasubstanceuse
disorder,whicheventuallymighthelpidentifythoseatincreasedriskfordrug
addiction. Identifyinggeneslinkedtoaddictionisonlythefirststep.
Candidate-generesearchexaminesthelinksbetweensubstanceuseand
specificgenesthatencodeproteinsthatappeartoberelatedtoaddiction.For
example,researchershavefoundconnectionsbetweenvariousaspectsof
cocaineaddictionandthegenesthatencodeforparticulardopaminereceptors
andtheenzymesthatbreakdownthisneurotransmitter.
Becauseenvironmentalfactorstypicallyshapetheimpactofgenesondisease
risk,researchersmustalsoidentifyhowparticulargene-by-environment
interactionsinfluencethecourseofaddiction. Researchinthefieldof
epigeneticsisuncoveringhowtheenvironmentinduceslong-termchangesin
geneexpression—influencingthepatternofgeneexpression—withoutaltering
theDNAsequence.
Inanimalresearch,scientistsaredetermininghowlong-termcocaineexposure
changesgeneexpressioninthebrain,particularlyintherewardpathway.
Studieshavelinkedspecificcocaine-inducedepigeneticchangesto
neuroadaptations andbehavioralhallmarksofaddiction,suchassensitivityto
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cocaine’srewardingeffects. Theepigeneticchangesinducedbycocaine
canbepassedtothenextgeneration,evenifthedrugexposuredoesnotoccur
prenatally. Althoughmuchmoregeneticandepigeneticresearchisneeded,
understandingaddictionatthemolecularleveloffersgreatpromisefor
improvingdiagnosis,forexamplebydiscoveringbiomarkersfordisease
severityortreatmentresponse.
Althoughmoreresearchisneeded,brain-imagingmightbeusedtodetect
biomarkersfordrugaddictionvulnerability,asthesetechnologieshaveyielded
insightsintotheprocessesunderlyingcravingandhowmedicationsmayquell
thebrain’sresponsetococainecues. Arelativelynewneuroimaging
technologycalleddefault-modeorresting-statefunctionalmagneticresonance
imaging(rs-fMRI)revealsbrainactivitywhenpeoplearealertbutnotperforming
aparticulartask;researchersusethistechniquetocomparefunctionalbrain
networksofpeoplewhohaveusedcocaineforalongtimeandthosewhohave
not.Thesestudiessuggestthatthereisreducedconnectivitybetweenvarious
braincircuits andbetweenthetwohemispheres amongpeoplewith
cocainedependence.Researchershavealsocorrelatedreducedconnectivity
betweenparticularbraincircuitswithimportantaddiction-relatedbehaviors,
includingriskforrelapse andimpulsivity.
Neuroimagingtechnologiesarealsodocumentinghowthebrainsofcocaine
usersmayrecoverafterperiodsofabstinence.Forexample,thesetechniques
indicatethatyearsofcocaineuseareassociatedwithreducedgreymatterin
particularbrainregions.However,peoplewhomaintainedcocaineabstinence
forapproximately9monthsshowedgreymatterlevelssimilartoorgreaterthan
thoseofpeoplewhohadneverusedthedrug. Furtheranalysisindicatedthat
theincreasedgreymatteroccurredinregionsotherthantheonesalteredby
cocaineuse,suggestingthattheneurobiologicalchangesinvolvedinrecovery
aremorecomplexthansimplyreversingthechangesrelatedtoaddiction. The
researchersalsofoundthatincreasedgreymattervolumeinbrainregions
involvedwithbehavioralcontrolwereassociatedwithlongerdurationof
abstinence.
fMRItechnologieshavealsorevealedthatabstinencefromcocainehas
important,restorativeeffectsonthebrain.Althoughcurrentcocaineusers
demonstratedreducedbrainactivityinabraincircuitthatmediatesresponse
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inhibitionduringamotorcontroltask,individualswhohadattainedabstinence
foranaverageof8monthsshowedsimilarpatternsofactivationandlevelsof
performancetothosewhohadneverusedthedrug. Theresultssuggestthat
abstinencehelpsrestorethefunctioningofthisbraincircuit.
Researchersareengagedinseverallarge-scale,collaborativeprojectstomap
thehumanconnectome,whichisthebrain’snetworkofinterconnectedcircuits.
Forexample,theNationalInstitutesofHealthsupportstheHumanConnectome
Projecttogeneratemapsofthedeveloping,adult,andagingbrain.Byhavinga
mapofthetypicalbrain,scientistswillfurtherunderstandhowneural
functioningdiffersinbehavioraldisorders—knowledgethatwilldriveimproved
diagnosticsandtreatments.
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WherecanIgetfurtherinformation
aboutcocaine?
Tolearnmoreaboutcocaineandotherdrugsofabuse,visittheNIDAwebsiteat
www.drugabuse.govorcontactDrugPubsat877-NIDA-NIH(877-643-2644;
TTY/TDD:240-645-0228).
NIDA'swebsiteincludes:
Informationondrugsofabuseandrelatedhealthconsequences
NIDApublications,news,andevents
Resourcesforhealthcareprofessionals,educators,andpatientsand
families
InformationonNIDAresearchstudiesandclinicaltrials
Fundinginformation(includingprogramannouncementsanddeadlines)
Internationalactivities
Linkstorelatedwebsites(accesstowebsitesofmanyotherorganizationsin
thefield)
InformationinSpanish(enespañol)
NIDAwebsitesandwebpages
www.drugabuse.gov
www.teens.drugabuse.gov
www.easyread.drugabuse.gov
www.drugabuse.gov/drugs-abuse/cocaine
www.researchstudies.drugabuse.gov
www.irp.drugabuse.gov
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Forphysicianinformation
NIDAMED:www.drugabuse.gov/nidamed
Otherwebsites
InformationoncocaineabuseisalsoavailablethroughthefollowingWebsite:
SubstanceAbuseandMentalHealthServices
Administration:www.samhsa.gov
DrugEnforcementAdministration:www.dea.gov
MonitoringtheFuture:www.monitoringthefuture.org/
ThePartnershipatDrugFree.org:www.drugfree.org/drug-guide
Thispublicationisavailableforyouruseandmaybereproducedinits
entiretywithoutpermissionfromtheNIDA.Citationofthesourceis
appreciated,usingthefollowinglanguage:Source:NationalInstituteon
DrugAbuse;NationalInstitutesofHealth;U.S.DepartmentofHealthand
HumanServices.
“This course was developed from the public domain document: Cocaine – National Institute on Drug Abuse
(NIDA) - NIH (2016).”