03 Cocaine

Question 1

what plant does cocaine come from?

Answer 1

found in the leaves of the coca shrub

Question 2

cocaine is (almost) the only local anesthetic that…

Answer 2

causes constriction rather than dilation of the blood vessels
-“nerve conduction blocks” thus it doesn’t need any epi to keep the anesthetic localized

Question 3

duration of cocaine anesthetic

Answer 3

very short duration of action

Question 4

toxic above what dosage?

Answer 4

30 mg, and addictive if consume systemically

Question 5

what are the different routes of administering cocaine?

Answer 5

IV, smoking, snorting, chewing (in order of effectiveness), it does have good transmucosal absortion

Question 6

how is it made?

Answer 6

coca leaves–> chemical extraction–> cocaine paste (not water soluble)–>oxidation, acids–> cocaine HCL (this is what is snorted or IV)—>baking soda—>”crack cocaine”, cocaine free base precipitates, Evaporation, broken into rocks for resale

Question 7

why is cocaine smoked?

Answer 7

all the blood passes thru the lungs

• 15% of cardiac output from left ventricle goes to the brain
• peak brain concentrations within 6-8 seconds

Question 8

cocaine is broken down where and how

Answer 8

in the liver by cholinesterase, broken down into Benzoylecgonine (BEG) which is the major urinary metabolite, this is still present for up to 10 days
- the second metabolite is Ecgonine or methylecgonine (MEG) and Benzoic acid

Question 9

what does MEG do?

Answer 9

depresses the heart by muscarinic receptor activation

Question 10

cocaine does what to neurotransmitters?

Answer 10

blocks neuronal transporter for NE, DA, and 5-HT (serotonin)

-it blocks reuptake

Question 11

mechanisms of Cocaine: ANS

Answer 11

1. Indirect agonist: blocks uptake-1 protein on noradrenergic terminal, leads to higher NE levels in the synaptic cleft
2. local anesthetic: blocks Na+ channels

Question 12

what does cocaine do to the heart?

Answer 12

• tachycardia and increase cardiac output (Beta-1)
• arrhythmias in some individuals (beta-1)
• local anesthetic effect (depresses heart)
• MEG from “crack” also depresses cardiac fn

Question 13

effect of cocaine on organ systems/vasculature

Answer 13

• vasoconstriction (alpha-1)=hypertension

- myocardial infarction: vasospasm of coronary arteries, may occur in minutes or up to 18 hours later

Question 14

cocaine effect in CNS

Answer 14

1. indirect agonist
   - blocks uptake-1 protein on NE, DA, and serotonergic terminals
   - leads to higher NE, DA, and 5-HT levels in synaptic cleft
2. local anesthetic
   - blocks Na+ channels
   - may cause seizures

Question 15

death from cocaine use can come from:

Answer 15

• cerebral infarction or vasospasm

- intracranial hemorrhage

Question 16

sign common to cocaine and cocaine free-base (or “crack”) abuse: acute intoxication

Answer 16

1. impaired judgment, hyper-vigilance, agitation, paranoia, with prolonged use: “toxic psychosis” resembling schizophrenia or mania
2. hypertension and tachycardia (significant)
   - “crack” signs may last 2 hr
   - “snorted” cocaine signs may last 4-6 hours

Question 17

signs common to cocaine and cocaine free-base (or “crack” abuse: withdrawal craving:

Answer 17

1. intense desire for drug

2. depression, fatigue, muscle pain, tremors, hypersomnia, they may feel really sick

Question 18

Signs common to CHRONIC cocaine intoxication:

Answer 18

1. “snorted” cocaine: chronic rhinitis (sniffing), sinusitis, ulceration (or degeneration) of nasal septum.
   - cocaine users also commonly brux
2. injected cocaine (10% incidence)
   - needle tracks

Question 19

free-base cocaine

Answer 19

the most processed, it is what is smoked, not snorted or IV

Question 20

signs common to chronic cocaine free-base “crack” abuse

Answer 20

1. laryngeal burns, hoarseness, difficulty swallowing
2. products of pyrolysis: brown stains on mucosal surface/brown particles in sputum and on teeth
3. stridor (high-pitched noisy respiration)
4. “crack” lung: (build up of fluid in lung)diffuse alveolar infiltrations on x-ray, pulmonary edema, scarring, chest pain, dyspnea

Question 21

signs of cocaine use in oral cavity

Answer 21

they often brush really well and cause gingival recession, even if their dental care is poop

2. intense bruxism, TMJ pain possible
3. for those who brush: unilateral abrasion of cervical margins of maxillary and mandibular arches due to vigorous brushing (left-side for right handers and visa versa)
4. post-extraction bleeding times may be prolonged
5. can get perforations in palate

Question 22

if patient uses cocaine, how do you treat them

Answer 22

• send them to emergency room, or

- make sure cocaine hasn’t been used in the last 4-6 hours

Question 23

dental local anesthetic and cocaine users:

Answer 23

• local: inadvertent i.v. injection of drug can directly depress the heart (blockade of TTX-R Na+ channel)
• Cocaine: sympathomimetic effects; its local anesthetic properties will have additive effects with L.A on the heart
• Methylecgonidine (MEG): depresses heart through muscarinic receptor activation

Question 24

what type of LA should be avoided and why

Answer 24

ester-linked LAs: allergic reactions (1-3), seizures(4-5)

1. cocaine metabolite-benzoic acid ester
2. para-amino benzoic acid derived LAs
3. benzoic acid from both sources may induce allergic reactions, further complicating the situation
4. avoid using procaine HCL
5. may augment pro-convulsive effects of cocaine

Question 25

so avoid using LA with____ and for long procedures consider using____

Answer 25

epi and preservatives, mepivacaine

Question 26

conscious sedation:

Answer 26

benzodiazepines, but don’t use midazolam (versed)

Question 27

propofol for

Answer 27

conscious sedation, nitrous oxide is safe for all office dental procedures for cocaine abusers

Question 28

ketamine

Answer 28

avoid it….