Quiz 2 Flashcards
What is a CNS depressant?
Reduces CNS response to outside signals - whether generated internally or externally to the body
Depressants are also known as:
Sedatives, anaesthetics, tranquilizers, relaxants, anxiolytics, hypnotics, anticonvulsants
How do we measure blood alcohol levels in the body?
BAC: mg of alcohol/100ml of blood
BAC of 80mg/ml = 0.08%
Why do people tend to eat less while drinking?
Alcohol is a food - releases energy
How long does it take to metabolize a single drink?
About an hour
T/F: absorption is slower on an empty stomach
False
Where does first pass metabolism occur when alcohol is administered the most common way?
Stomach
T/F: Males metabolize alcohol faster
True
Which chemical facilitates the passage of alcohol through the stomach?
Increased CO2
Alcohol distribution depends on:
Body size & composition (fat levels as alcohol is distributed in body water)
How much alcohol is metabolized in the liver?
85-90%
How much alcohol is metabolized in extra-hepatic sites (i.e., the stomach)
10-15%
How much alcohol is excreted unchanged?
5% through anywhere with glands (sweat, lungs)
What is the metabolic pathway for alcohol?
Broken down by alcohol dehydrogenase -> forms acetaldehyde -> broken down by acetaldehyde dehydrogenase -> forms acetic acid -> broken down with oxidation reaction -> produces CO2 + H2O + energy
What are 3 non-specific effects of alcohol
- Disturbs the relationship of protein in membrane
- Interacts with polar heads of phospholipids
- Alters lipid composition
What are 4 specific effects of alcohol?
- Acts as NT binding site
- Modifies gating system inside channel
- Stimulates Gs which are linked to adenylyl cyclase
- Direct interaction with channel protein
What receptor is affected by both alcohol and glutamate
NMDA (they block Ca2+ & Na+ from entering cell)
What is the chronic effect of alcohol on the NMDA receptor?
Upregulation (pharmacodynamic tolerance)
In a chronic drinker, the glutamate:
Moves to be able to function with alcohol in the system
Alcohol _______ GABA(a) receptor transmission
Enhances
What is the effect of alcohol on Cl- in chronic and acute use?
Decrease in conductance; influx of Cl-
How is DA affected by alcohol?
Indirectly. When GABA neuron in VTA releasing inhibitory substance, more GABA is released, exciting DA neurons
How does alcohol affect serotonin & acetylcholine
- Increased depolarization
- Increased hyperexcitability
- When withdrawn, behaviour may seem like mania or psychosis
What are 3 things barbituates are used for?
- Treatment of anxiety and insomnia
- Anticonvulsant
- Surgical anesthesia
Drugs ending in -barbital, -butal, or -tal are_______
Barbituates
What is the most common way to administer barbituates?
Water-soluble salt preparation
What is the issue with barbituates?
Most have a very narrow therapeutic index (very easy to OD)
What are 4 classic barbituates
Secobarbital (seconyl); amobarbital (amytal); thiopental (pentothal); pentobarbital (nembutal)
This barbituate is also known as truth serum
Thiopental (pentothal)
Why were Benzodiazepines invented?
To have a larger therapeutic window than barbituates, people were ODing too easily
This drug, “Mothers little helper”, invented in 1963 is when housewives became drug addicts
Valium
Rohypnol (flunitrazepam) is more commonly known as:
Roofies
Gamma-Hydroxybutyrate (GHB) works well because of it’s similar structure to ____
GABA
GHB was created as a ______ and used to treat ______but was taken off the market due to _______
Sedative/anaesthetic; cataplexy associated with narcolepsy; it’s use as a date-rape drug
What are symptoms of too much endogenous GHB?
brain damage, seizures, loss of muscular control, profound intellectual delay
What is an inhalant?
Volatile solvents (aerosols, gases)
What are behavioural effects of inhalants?
Intoxication and light anaesthesia
How do inhalants work?
Physiochemical processes in cell membranes (non-specific) & by acting as GABA and glutamate agonists
Cocaine and amphetamine are examples of what class of drugs?
Psychostimulants
Psychostimulants have the ability to affect _______ transmitters.
Monoamine
T/F: Modfications to psychostimulant drug structure is common.
True in amphetamines
The cocaine molecule:
Is odd, doesn’t look like any biological molecules or amphetamines, weird structure blocks reuptake site
What are some common forms of cocaine?
Coca leaves (used in Bolivia), crystallized salt (cocaine hydrochloride - snorting & IVs; often mixed with baby formula), Freebase (alkaline solution and organic solvent - prepare for smoking), crack (heated with baking soda and dried - smokable, affordable)
IV administration of cocaine or smoking, which one lasts longer?
Smoking - lasts roughly 4 hours, IV lasts 2
How is cocaine metabolized?
Enzymes in plasma and liver
What is the primary metabolite for cocaine?
Benzoylecgonine (tested for in urine)
What metabolite is present when cocaine is mixed with alcohol?
Cocaethylene
When applied topically, procaine, novocaine, etc.:
Block volatge-dependent Na+ channels (topical creams for pain relief)
What are some mild-moderate effects of psychostimulant use?
- Mood amplification (both euphoria and dysphoria)
- Heightened energy
- Sleep disturbance, insomnia
- Motor excitement, restlessness
- Talkativeness, pressure of speech
- Hyperactive ideation
- Increased sexual interest
- Anger, verbal aggression
- Mild to moderate anorexia
- Inflated self-esteem
What are effects of abusing psychostimulants?
- Irritability, hostility, anxiety, fear, withdrawal
- Extreme energy or exhaustion
- Total insomnia
- Compuslive motor sterotypies
- Rambling, incoherent speech
- Decreased sexual interest
- Possibility for extreme violence
- Delusions of grandiosity
- Total anorexia
What are some side effects of cocaine use?
Expensive, mimicks activation of sympathetic nervous system (increased heart rate, blood pressure, glucose utilization), alters plasticity, tremors, loss of motor coordination, seizures
What does cocaine toxicity look like?
Heart attack (big ones, disproportionate to age), stroke (usually hemorrhagic), permanent brain damage. Related to vascular insufficiency and decreased blood flow due to vasoconstriction
What amphetamine was readily available in health food stores until a few years ago?
Ephedra
This drug is known as the original amphetamine, and used as an inhaler for asthma
Benzedrine
What is an amphetamine (AMPH)?
- All related someway to monoamine alkaloid phenethylamine (naturally ocurring trace nutrient)
- Similar to phenylalanine (precursor to tyrosine, found in meat and milk)
A toxic build up of phenylalanine due to deficient or absent enzyme is called: (acronym)
PKU
What is different about MDMA compared to AMPH?
- Double methylation
- Does not work on DA or NE
- Classified as hallucinogen
What is the average half life of AMPH?
7-30 hours depending on urinary pH
AMPHs are one of the only classes that are able to:
Have a direct action on DA transmitters to cause a conformational change that reverses the direction of transmitter flow (as well as blocking re-uptake of released DA)
What system does MDMA most effect?
5-HT (serotonin); hardly any effects on catecholamines
Why is MDMA deadly?
Raises body temp so much that brains/organs cook from inside
What are behavioural effects of MDMA?
- Doesn’t produce whole profile of effects as amphetamine
- In addition to stimulant effects, produces entactogenic effects that arise from selective affinity for 5-HT neurons
MDMA side effects and toxicity result from:
- Hyperthermia leading to febrile seizure (can cause brain damage)
- Lack of O2/CO2 exchange (hyperventilation)
- Dehydration
- Hypovolemia (sweating, vomiting, diarrhea, menstruation = imbalance of electrolytes = can lead to water toxicity)
What is the unifying property of the general stimulants?
Transmitter is not one of the monoamines (nicotine works on ACh); do not cause psychomotor effects
The half-life of nicotine is about ___ hours, leading to morning loading to achieve ______
2; steady-state levels
What are some common routes of nicotine administration?
Cigarette, nasal spray, patch, chewing gum
Most nicotine is metbolized in the _______ by enzyme _______
liver; CYP2A6
Nicotine _______ muscle tone in skeletal muscles, and ______ tone in smooth muscle sites
Decreases; increases
What are some physiological effects of nicotine?
- Cardiovascular effects (increase heart rate, blood pressure)
- Decrease in urination, changes to urinary pH
- Release of EPI in PNS causing general arousal of CNS
- Increased respiration
- Release of DA and NE in multiple brain regions
- Interacts in a complex fashion with serotonin system
What are some behavioural effects of nicotine?
Increase in arousal, concentration, vigilance, working memory
What happens when nicotine (not smoked) is given to rat mothers?
Babies are smarter, have better memory
What are nicotine withdrawal symptoms?
- Decreased heart rate
- Increased eating (weight gain)
- Depression
- Inability to concentrate/pull thoughts
- Sleep disruption & increased awakening
- Anxiety, anger, agression, nervousness, fear, headaches, dizziness, tremors, nausea
T/F: Caffeine changes blood flow, and is good for headaches
True
What is the half life of caffeine?
2.5-4.5 hours
Caffeine is metabolized in the liver by:
CYP1A2
Caffeine molecule can be broken into _______ (84%), _______ (12%) & _______ (4%)
paraxanthine, theobromine, theophylline
Caffeine is an antagonist for which receptors?
Adenosine
What are some acute physiological effects of caffeine?
- Increased blood pressure, heart rate, respiration
- Vasconstriction in periphery
- Increase in EPI
- Increase in urination
- Decrease in smooth muscle tone
What are some acute behavioural effects of caffeine?
- Increase in arousal, concentration, vigilance, working memory, reaction time, cognitive performance
- Assists in pain relief
- Tolerance, dependence and sensitization
What are withdrawal effects of caffeine?
- Loss of concentration
- Headache, irritability, fatigue, mild mood depression
- Rebound effects of compensatory increases in adenosine in multiple systems
What are side effects and toxicty of caffeine?
- Caffeinism (caused by excess caffeine)
- Heart palpitations, heart arrythmia, insomnia, diarrhea (aggressive), restlessness, anxiety, involuntary contractions of limbs, tremors, seizures, psychotic behaviour
