stimulants, anorexigenics and hallucinogens

Question 1

What is the mechanism of action of cocaine?

Answer 1

inhibits reuptake by presynaptic neuron of dopamine, serotonin and norepinephrine by blocking the transporter (DAT, SERT, NET) on the presynaptic membrane

Question 2

What are the amphetamine-like drugs? What is their mechanism of action?

Answer 2

amphetamine, methamphetamine, methylphenidate (ritalin), phentermine

1) They are competing substrates for the reuptake transporter of dopamine (DAT) thereby inhibiting the reuptake by the presynaptic neuron.
2) compete with dopamine for the vesicular monoamine transporter (VMAT) that loads dopamine into vesicles. Less dopamine gets loaded into vesicles and more dopamine is released non-vesicularly into the synapse

Question 3

what is the mechanism of action of caffeine?

Answer 3

is a competitive antagonist of adenosine receptors

increasing adenosine levels promote sleep

Question 4

what is the mechanism of nicotine?

Answer 4

agonist of central nicotinic acetylcholine receptors

Question 5

What are the signs of stimulant withdrawal?

Answer 5

“crash” period with intense drug craving, depression, anxiety and agitation
Intermediate phase - fatigue, loss of mental energy, decreased interest in environment

Question 6

What are the effects of cocaine outside the CNS? What are the effects of amphetamines outside the CNS?

Answer 6

cocaine - increased cardiac contractility, heart rate and blood pressure (can cause stroke with chronic use); coronary vasoconstriction (increases norepi in the synapse of alpha receptors in blood vessels). High risk of arrhythmias and heart attacks
amphetamines - increased blood pressure with possible bradycardia. High risk of arrhythmias

Question 7

How is cocaine eliminated? How are amphetamines eliminated?

Answer 7

cocaine - metabolized by esterases in the plasma and liver to benzoylecgonine and excreted by the kidney
amphetamines - not metabolized. Excreted unchanged by the kidney

Question 8

What combination of drugs are FDA approved for weight loss?

Answer 8

phentermine and topiramate

Question 9

What is the treatment for ADHD?

Answer 9

amphetamine, methamphetamine or methylphenidate

Question 10

What are the indications for modafinil?

Answer 10

a stimulant for excessive sleepiness due to narcolepsy, obstructive sleep apnea and shift work sleep disorder
off label treatment for ADHD

Question 11

What are the indications for caffeine?

Answer 11

episodes of apnea and bradycardia in premature infants
lumbar puncture headaches
augmentation of seizure induction for electroconvulsive therapy for depression

Question 12

What are the CNS effects of nicotine? Peripheral effects?

Answer 12

CNS effects - arousal, relaxation, enhances mood, attention and reaction time.
Peripheral effects - low doses: increased HR, BP, CO and vasoconstriction. high doses: releases adrenal catecholamines

Question 13

What are the synthetic cathinones? What is the mechanism of action of the synthetic cathinones?

Answer 13

mephedrone, methylone

stimulates monoamine neurotransmitter release and inhibiting its reuptake from the synaptic cleft

Question 14

What are the CNS effects of synthetic cathinones? Peripheral effects?

Answer 14

CNS: paranoia, auditory and tactile hallucinations, psychosis, myoclonus
Peripheral: hyperthermia, hyponatremia, tachycardia, rhabdomyolysis and compartment syndrome

Question 15

Which amphetamine has the longest half life?

Answer 15

phentermine, the long half life lowers its potential for abuse

Question 16

What are the indications for amphetamine?

Answer 16

ADHD, narcolepsy

Question 17

What are the indications for methamphetamine?

Answer 17

ADHD, narcolepsy, exogenous obesity

Question 18

What are the indications for methylphenidate?

Answer 18

ADHA, narcolepsy, depression in medically ill older adults

Question 19

What are the indications for phentermine?

Answer 19

exogenous obesity

Question 20

What are the major groups of hallucinogens? What important drugs fall into these major groups?

Answer 20

5HT2A partial agonists - LSD, MDMA, mescaline in peyote, psilocybin in mushrooms
Glutamate antagonists - PCP
muscarinic antagonists - no important drugs

Question 21

What are the peripheral effects of hallucinogens?

Answer 21

mydriasis, increased BP and HR

Question 22

How are LSD and MDMA eliminated? How long are their half-lives/

Answer 22

by the liver.

half life of LSD = 4 hours, MDMA = 7 hours

Question 23

Which drugs are abused but not addictive/won’t produce withdrawal symptoms?

Answer 23

the 5HT2A partial agonists, LSD and MDMA

Question 24

What are the symptoms of LSD and MDMA use?

Answer 24

visual hallucinations, synesthesias (crossing of sensory modalities like smelling colors), dilation of time, feelings of oneness with the universe

Question 25

What are the symptoms of PCP use? At high toxic doses?

Answer 25

hostile or combative behavior
visual and auditory hallucinations
numbness and insensitivity to pain
Increased HR, BP and sweating
At high toxic doses: general anesthesia, coma with paralytic mydriasis, catatonia

Question 26

What type of drug is dronabinol? What are its indications?

Answer 26

Dronabinol is an synthetic cannabinoid that is used for anorexia in patients with AIDS, last resort antiemetic for cancer patients, prophylaxis and treatment of post-surgical nausea

Question 27

What are the proposed medical uses of medical marijuana?

Answer 27

nausea
apetite stimulation
reduction of intraocular pressure (nonsense according to Blitzer)
reduction of spasticity of patients with multiple sclerosis

Question 28

What drug is a cannabinoid receptor antagonist? What are its indications?

Answer 28

rimonabant is a CB1 receptor antagonist that is used to treat obesity and help patients lose weight