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Flashcards in Drugs of Abuse Deck (28):
1

Drugs that activate G protein coupled receptors

• opioids
• cannabinoids
• hydroxybutyric acid (GHB)
• LSD, mescaline, psilocybin

2

main receptor target of opioids

OR (Gio)

Agonist

3

Drugs that bind to Inotropic Receptors and ion channels

• nicotine
• alcohol
• benzodiazepines
• phencyclidine, ketamine

4

drugs that bind to transporters of biogenic amines

• ampheatmines
• ecstacy

5

Symptoms of opioid withdrawal

➢ Intense dysphoria, nausea vomiting, muscle aches, Lacrimation, rhinorrhea
➢ Yawning and sweating
➢ Chills, goose flesh (“cold turkey”)
➢ Tremors, muscle jerks (“kicking the habit”)

6

treatment of opioid withdrawal

➢ Treatment of withdrawal: substituting with Methadone or buprenorphine…followed by its slow dose reduction
➢ Clonidine is also found to be effective for withdrawal
➢ Use of opioid antagonist (naloxone, naltrexone) in an abuser may precipitate withdrawal (precipitated withdrawal)

7

CNS effects of Cannabinoids

• A feeling of being “High”
• euphoria
• uncontrollable laughter
• increased appetite
• altered sense of time
• difficulty concentrating
• decreased memory
• Vasodilation and tachycardia
• Habitual users show Reddened conjunctiva

8

cannabinoids MOA

• THC is an agonist at CB1 & CB2 (cannabinoid) receptors
• CB receptors are in many areas of the CNS
➢ Therapeutic Used THC analog is Dronabinol
➢ used to treat –
• Nausea & vomiting in patients receiving cancer chemotherapy
➢ Rimonabant CB1 receptor agonist
➢ FDA approved use to treat obesity, smoking cessation (offlabel use)

9

Rimonabant

CB1 receptor agonist

10

g-HydroxyButyrate (GHB)

➢ Site of action: weak agonist on GABAB receptor
➢ Lactone (GBL) may be found in nail polish remover
➢ Effects – used as hypnotic:
• Euphoria
• Enhanced sensory perception
• Feeling of social closeness
• Amnesia, general anesthesia, coma, death
➢ Pharmaceutical properties: rapid onset, short half-life
• –tmax = 20-30 min; t1/2 = 60 min
• Odorless liquid
➢ “Club drug” “date rape drug”

11

psilocybin

hallucinogen

12

Dronabinol

Therapeutic Used THC analog

used to treat –
• Nausea & vomiting in patients receiving cancer chemotherapy

13

mescalin

hallucinogen

14

Rimonabant

CB1 receptor agonist

15

LSD has activity at

agonist activity at 5-HT2A receptors

16

Smoking's effects on pregnancy

• ↑ abortions, ↓ birth weight, ↑ neonatal morbidity & mortality
• delayed physical & mental development in children.

17

Nicotine MOA

nACh-R: Activation in VTA → release of DA

18

Treatment for smoking

➢ Clonidine (off label) – a2 adrenergic agonist; reduces anxiety, irritability and craving during withdrawal.
➢ Varenicline – partial agonist at a4b2 nACh-R for smoking cessation
➢ Bupropion – antidepressant & nACh-R antagonist

19

Ketamine and Phencyclidine (PCP)

➢ Ketamine (dissociative anesthetic) is structurally related to PCP, is also abused
• A “pyschomimetic”.

➢ Phencyclidine may be smoked (by mixing the powder with tobacco), "snorted," taken orally, or injected intravenously.

➢ Also called as “Angel dust”, “Hog” “Special K”
➢ Mechanism: NMDA antagonist
➢ The most dangerous hallucinogen

Effects
• Euphoria (can be addictive)
• Physiological effects (diagnostic)
• hyperreflexia, hypersalivation, nystagmus, marked hypertension , seizures (fatal)
• Dissociation
-->loss of contact with reality (self, senses)
-->inability to communicate
-->aggression, panic, violence

20

Effects of cocaine and amphetamines

• Elevate mood, induce euphoria, increase alertness and reduce fatigue
• Coke high lasts 30-60 min; Meth lasts 12-24 hr.
• Smoked or injected, the “rush” is intensely pleasurable for a period of sec to min, followed by a longer period of milder euphoria mixed with increased anxiety and a strong desire to obtain more of the drug.
• Repeated use over short times → toxic paranoid psychosis which is clinically indistinguishable from the florid early signs of schizophrenia.

21

Varenicline

partial agonist at a4b2 nACh-R for smoking cessation

22

MOA Cocaine and Amphetamines

➢ Cocaine acts by blocking the presynaptic DA transporter (DAT) (Also NET and SERT)
➢ Amphetamine blocks DAT, but also causes DAT to run backwards, releasing DA from the terminal cytoplasm
➢ MOA may also involve NET & SERT. Mice lacking DAT can still be made addicted to these drugs.

23

Reward center is a set of DAergic cells from the ventral tegmental area (VTA) to the nucleus accumbens.

cocaine and amphetamines

24

Cocaine overdose symptoms

cardiac toxicity, irregular breathing and apnea, itching (cocaine ‘bugs’), tachycardia, impotence, paranoid delusions & severe hypertension → stroke or myocardial infarction.

25

amphetamine overdose symptoms

tachycardia, hypertension, mydriasis, loss of appetite

26

MDMA (ecstacy) toxicity

➢ A common “club drug” used for increased energy
& pleasurable feelings such as peacefulness & empathy
➢ Causes euphoria, facilitate interpersonal communication, heightens sexuality
➢ Hyperthermia is a potentially fatal side effect of use of high doses of ecstasy – serotonin syndrome (or toxidrome).

MOA
➢ Ecstasy causes a massive release of serotonin. It has preferential affinity for SERT.

27

cardiac toxicity, irregular breathing and apnea, itching (cocaine ‘bugs’), tachycardia, impotence, paranoid delusions & severe hypertension → stroke or myocardial infarction.

cocaine overdose

28

Withdrawl signs of both amphetamine and cocaine

increased appetite, exhaution, increased sleep time and mental depression