Drug & Substance Abuse

Question 1

Marijuana:

Answer 1

• Tetra-hydro-cannibanoil (THC) and Cannabinol (CBD)
• Cannabinol has shown to express the positive symptoms of marijuana without the negative symptoms of THC
• Contains 2 receptors: CB1 and CB2

Question 2

Opioids:

Answer 2

Opioid Peptides: Enkephalins, Endorphins & Dynorphins
Opioid Receptors: Kappa, um and gabba receptors

-U (mu) opioid receptors on GABA interneurons in the VTA inhibit activity, relieving GABA- mediated inhibition on VTA neurons. (increases the reward pathway)

Question 3

Hallucinogens:

Answer 3

Natural:
-Ergotamines, Mescalines, Psilocin and Atropine/ Scopolamine

Synthetic:
-LSD, Phencyclidine (PCP), Benztropine and Amphetamine Analgoues (TMA, MDA & MDMA)

Question 4

What is the mechanism of action of Atropine, Scopolamine and Benztropine?

Answer 4

Reduce the activity of ACh pathways

Question 5

True or False: Cross Tolerance can occur in drugs with different mechanisms.

Answer 5

FALSE.

Cross tolerance occurs with drugs with the same mechanism of action.

Question 6

Phencyclidine (PCP):

Answer 6

• Angel dust, peace pill
• Dissociative analogue similar to ketamine, which antagonizes the glutamate NMDA receptor.
• ->Produces an altered body image.

Question 7

Opioid Treatment:

Answer 7

• Methadone (long action oral dose)

- Naloxone/ naltrexone (opioid antagonist)

Question 8

Nicotine Treatment:

Answer 8

-Nicotine Replacement Therapy

Question 9

Varenicline:

Answer 9

-Anti-depressant and partial nicotine agonist

Question 10

Bupropion:

Answer 10

–>Anti-depresant also used for long term smoking cessation

Question 11

Ethanol:

Answer 11

-Metabolized by P450 cytochrome enzymes
-Depressant drug
-Chronic alcohol consumption leads to chronic stress
-Acts onGABA, NMDA and 5-HT receptors
–Synthesizes beta- endorphins and acts on GABA/ dopaminergic pathway
(surpasses neutron hyper-excitability)

Question 12

Disulfiram (Antabuse):

Answer 12

• Used to treat alcoholism
• Inhibitor of ALDH (can’t produce CH3COOH)
• Causes Acetaldehyde to build up
• Metabolized by the liver

Question 13

Acamprosate:

Answer 13

-Glutamate receptor antagonist (NMDA antagonist)
–Synthetic taurine derivative resembling GABA
-Decreases excitatory action of glutamate in the CNS
T1/2= 20-33 hours
-Excreted unchanged by the liver

Question 14

Naltrexone:

Answer 14

• Kappa (k) and Mu (u) receptor opioid antagonist

- Decreases dopamine- reward pathway

Question 15

Methanol:

Answer 15

Metabolized by ADH to formaldehyde, which is metabolized by ALDH to form formic acid.
-Both metabolites are harmful to human tissues resulting in blindness, acidosis and death.

Question 16

Treatment of Methanol Poisoning:

Answer 16

-Saturate ADH in Ethanol (0.08-0.10) to prevent formaldehyde formation + bicarbonate to reduce acidosis

Question 17

Fomepizole:

Answer 17

ADH inhibitor used for methanol poisoning

Question 18

Ethylene Glycol:

Answer 18

Metabolized by ADH and ALDH to toxic aldehydes + oxalic acid

Question 19

Treatment of Ethylene Glycol:

Answer 19

-Soak ADH and ALDH in Ethanol or Fomepizole, bicarbonate, dialysis, and then fluids and calcium