Final Review Flashcards
Describe the mechanisms of caffeine. How does this mechanism explain the clinical effects of the drug?
Caffeine acts as an adenosine antagonist, blocking the effects of adenosine
It is a competitive inhibitor, meaning it competes for the same site and inhibits its actions
This explains its clinical effects because adenosine has sedative properties that increase throughout the day. It stimulates GABAergic neurons in the DA reward system, thus inhibiting DA rewards.
Since caffeine blocks adenosine it keeps people alert and it indirectly activates the reward system
What are the positive and negative effects of caffeine?
Positive aspects:
- Cardiovascular function: reduces disease, constricts cerebral vessels decreasing blood flow and reducing pressure, increases contractility & output
- GI: improves glucose metabolism, insulin secretion, and secretion of gastric acid
- Broncial relaxation (anti asthmatic)
- Reduces risk of cancer
- Neurological: protect against Parkinsons and symptoms of MS
Cognition/Mental Health: Reduces Alzheimers risk (polyphenols), improves memory, and decreases depression
Negative aspects:
- Anxiogenic properties (can cause anxiety)
- Tremors, rapid breathing
- Sleep disturbances
- Overdose can occur if drank too fast/too much
Caffeine is a _____ anlkaloid
Xanthine - stimulates the CNS, acts on kidneys to produce urine, stimulates cardiac muscles, and relaxes smooth muscles
How is caffeine absorbed and metabolized (pharmacokinetics) in the body?
99% of caffeine is taken into the blood within 45 min - it is absorbed quickly and freely throughout the body as it is lipid & water soluble
It is metabolized by the hepatic enzyme CYP1A2 and is broken down into 3 metabolites: Parazanthine (increases lipolysis), Theobromine (dilates blood v. and increases urine vol.), and Theophylline (relaxes bronchi)
2-3% of caffeine is excrete unchanged (not metabolized)
What effect for Flyvoxamine (SSRI) have of caffeine effects?
It inhibits CYP1A2 - people on this SSRI will have a harder time metabolizing caffeine
What is caffeine’s half life?
2-10 hours
It is extended in infants, pregnant women, and elderly people
The half life decreases while smoking a cigarette
What is caffenism and when does it occur?
Caffeinnism is a syndrome produced by overuse/overdose from caffeine - occurs at doses higher than 10mg (100 cups)
It causes:
- CNS: anxiety/agistation/insomnia
- PNS: tachycardia/hypertension/GI issues
What is the recommended caffeine intake for adults?
400mg
300 mg from pregnant women - but none is better
Does caffeine negatively impact pregnant women?
It can cause a moderate degree of getal growth restriction, can increase risk of mar carriage
What are the withdrawal symptoms of caffeine?
Headache, drowsiness, fatigue, impaired intellectual and motor performance, and negative mood state
Symptoms subside after 1-2 days
Can people become dependent on caffeine?
No. However, it is associated with habituation and tolerance with high doses (750-1200mg/day)
What are some health issues related to tobacco?
- The single greatest cause of preventable death
- Accounts for 30% of all cancer deaths
What are the pharmacokinetics of nicotine?
It is absorbed rapidly and completely, reaching the brain in 7 seconds. It is saturated in the blood which results in the ‘head-rush’
It is metabolizes by hepatic enzyme CYP-2A6 and produces the metabolite cotinine which can remain in the blood for 48 hours
What is the half-life of nicotine?
2 hours
Describe the mechanism of action of nicotine.
Nicotine activates nicotinic acetylcholine receptors (nAChRs) which are found in the presynaptic terminals of DA neurons, ACh neurons, and Glu neurons
nAChR activation causes increase in BP & HR, releases epinephrine, and enhances GI
Nicotine acts as an agonist by stimulating the α2α4 nACh receptors which increases DA levels in the limbic system - critical for the rewarding effects
What are the pharmacological effects of nicotine?
- May cause nauesa or vomitting
- Stimulates hypothalamus which released ADH, causing fluid retention
- Decreased muscle tone
- Appetite suppression /weight loss
- Increased blood flow to reward centres
- Anti depressant effects
What can prenatal exposure to smoke cause?
- 2-3-fold increase in being small for gestational age (SGA)
- Pediatric asthma, SIDS, various immunological diseases
- Fetal hypoxia (lack of O2) -> lower IQ
List the nicotine-replacement therapy options. Discuss their efficacy.
- Transdermal patch - nicotine plasma levels gradually increase so shouldn’t provide an individual with a ‘crash’
- Nicotine gum: nicotine plasma levels decrease quickly providing people with the urge to smoke
- Nicotine nasal spray: very low nicotine levels
- Nicotine inhalers
- E-cigarettes: very accessible, and are linked to less smoking cessation
All NRT treatments are essentially equally effective due to their overlap (besides varenicline which is the best)
What are the pharmacotherapeutic options for smoking cessation ?
Anti depressants:
- Bupropion (wellbutrin, Zyban)
- Varenicline (Champix) - most effective
- CBT
What is a psychedelic drug?
Class of drugs that cause hallucinations and out-of-body experiences
List the major classes of psychedelic drugs, their associated drugs, and their mechanisms of action
Anticholinergic - scopolamine
- They are competitive muscarinic ACh antagonists
Catecholaminelike - mescaline, ecstacy
- 5-HT2A agonist
Serotoninlike or Monoaminergic - LSD
- 5-HT2A agonist
Glutaminergic NMDAR antagonist - Ketamine, phencyclidine
- noncompetitive antagonists of NMDAR
Opioid Kappa Receptor agonist - Salvinorin A
What is atropine?
Atropine is found the the Atropa belladonna plant and reverses cholinesterase inhibitors, increasing ACh production
What are the pharmacological effects of scopolamine?
Acts on the PNs to produce an anticholinergic syndrome: dry mouth, reduced sweating, dry skin, increased body temp, tachycardia
Acts on the CNS:
Low dose: drowsiness, profound amnesia, mental confusion, absence of REM
High(toxic) dose: delirium, coma, respiratory depression
Which two psychadelic drugs are found in nutmeg?
Myristin and Elemicin
Both catecholaminlike psychedelics
What is the origin of mescaline?
It is found in the peyote cactus and has a crown that is cut and dried into a hard brown disk called the mescal button
Can be chewed or soaked to make a drink
What are the effects of mescaline? How long do they last?
Produces an acute psychotomimetic state with prominent effects on the visual system
Single dose lasts up to 10 hours
Discuss the positive and negative symptoms of ecstasy?
Positive:
- Increased insight, empathy, enhanced communication, and transcendent religious experiences
Negative:
- Hyperthermia (overheating)
- Tachycardia
- Convulsions
- Kidney failure
- Cardiac arrhythmia
- Dealth (malignant hypothermia)
_________ can reverse malignant hypothermia in people who have taken MDMA
dantrolene
How does MDMA differ from mescaline?
MDMA is more potent and toxic as it inducesserotonergic neurotoxicity
MDMA is a releaser and/or reuptake inhibitor of monoamines
Which brain areas does LSD activate?
Medial prefrontal cortex and anterior cingulate cortex
What effects does LSD have on its user?
- Alterations in perception
- Temporal changes
- Visual alteration
- Euphoric mood
What is hallucination persisting perception disorder?
It is a flashback of a visual experience that occurs after the drug has passed - can occur after using LSD
They are often long-term, recurrent, and have an unpleasant dysphoric effect
What are the LSD-induced psychedelic experience phases?
Somatic phase: CNS stimulation and autonomic changes
Sensory (perceptual) stage: sensory distortions and pseudo hallucinations
Psychic phase: maximum drug effect: changes in mood, disruption of thought processes, altered time perception, possible ‘bad’ trip
How are Glutaminergic NMDAR Antagonists (PCP & Ketamine) different from other psychedelics?
They are structurally unrelated and do not have effects of 5-HT, ACh, or DA
The have psychotomimetic, analgesic, and amnestic properties
How does ketamine and PCP inhibit NMDA receptor’s?
- Blockage of open channel by occupying a site within the channel of the receptor protein
- Reduction in the frequency of NMDA channel opening by binding to second attachment site on the outside of the receptor protein
What psychological effects does ketamine and PCP have?
Induces a psychotic state: rigid, unable to speak, appear very drunk, amnesia, coma/stupor
Respiration does not become depressed in ketamine
What are the 3 primary goals of the cannabis law?
- Legalize, regulate, and restrict sale of recreational cannabis
- Restrict access of cannabis to youth
- Limit the illicit cannabis trade
What are the 3 psychoactive compounds produced by the cannabis sativa plant?
- Delta-9-tatrahydrocannabinol (THC)
- Cannabinol (minor component)
- Cannabidiol (minor component)
Explain each term and put in order of potency: (a) Ganja, (b) hashish, and (c) marijuana
- hashish- dried resin of the female flower
- Ganja: dried tops of the female flower
- Marijuana: Dried remainder of plant
How is THC administered?
Joint, blunt, pipe, bong, and edibles