Exam 2 Flashcards
Drug
any substance that alters mental state or biological function (excludes nutrients considered to be related to normal function)
generic name
legal, official or non-proprietary name
chemical name
description according to specific rules of organic chemistry
brand name
name given by the manufacturer
street name
mainly illicit drugs
Paracelsus
All substances are poisons: there is none which is not a poison. The right dose differentiates a poison and a remedy.
Pure food and drug act
regulated labeling of patent medicines and created the FDA
Marijuana Tax Act
Banned nonmedical use of cannabis (overturned by US supreme court in 1969)
Controlled Substances Act
Established the schedule of controlled substances and created the DEA
patent medicine
defined as the compounds promoted and sold as medical cure that do not work as promoted
Five classes of drugs (related by Controlled substances act)
- narcotics
- depressants
- stimulants
- hallucinogens
- anabolic steroids
Schedule 1 vs 5
1- high potential for abuse with little medical use
5- low potential for abuse and lots of medical use
depressants
- sedate, calm, and relax
- types of sedative/hypnotics: barbiturates, alcohol
- medical uses: epilepsy, muscle relaxant, anxiety
anesthetics/analgesics
- block pain/sensation
- types: narcotics and inhalents
- medical uses: sedation, medical procedures, pain relief from disease
- significant recreational use
psychostimulants
- low to moderate doses increase alertness, reduce fatigue, elevates modd
- types: amphetamine, cocaine, caffeine, nicotine
- medical uses: narcolepsy, attention deficit
- predominant use is recreational
hallucinogens and psychedelics
- mind altering: cause changes in a persons perception of reality
- types: LSD, mescaline, psilocybin
- limited medical uses
- predominant use is recreational
psychotherapeutics
- antipsychotics/neuroleptics that sedate, calm, and relax
- types: chlorpromazine, thioridazine, haloperidol
- medical uses: schizophrenia, calm highly hyper-excited patients
- also antidepressants (used for clinical depression)
- also anti-manics (used to calm the modd swings of bipolar disorder and main type is lithium)
pharmacology
the scientific study of the effect of drugs on biological system
pharmacokinetics (PK)
- explores what the body does to the drug
- branch of pharmocology dedicated to the determination of the fate of substances administered externally to a living organism
- ADME: absorption, distribution, metabolism, and excretion
pharmcodynamics (PD)
- study of the biochemical and physiological effects of drugs on the body (what the drug does to the body)
drug action
the specific molecular changes produced by a drug when it binds to a particular target site or receptor. The effect produced by a drug is an alternation of a natural physiological function or process.
most common drug targets?
transporters, ion channels, receptors, and enzymes
enzyme
biological molecule that cause a specific biochemical reaction
medicinal (instrumental use)
drug used for specific purpose other than getting high
recreational use
drug used to achieve some pleasurable effect
drug abuse
drug taking behavior resulting in some form of physical, mental, or social impairment
drug effect
alterations in physiological or psycholgocial function caused by the molecular changes as a result of drug action
addiction
defined as compulsive drug-seeking behavior where acquiring and using a drug becomes the most important activity in the user’s life
ADME
administration/absorption
distribution
metabolism
excretion
common routes of administration
oral, injection, inhalation, topical
the first pass effect
-metabolism of a drug by the liver reduces the amount of available drug before it reaches the systemic circulation
Three types of injections
- Subcutaneous (just below skin)
- Intramuscular (into muscle)
- intravenous (into bloodstream)
three types of topical administration
- intranasal
- sublingual (under tongue)
- transdermal
ADME: absorption
- refers to getting the drug from where it is administered to the blood circulation
- many barriers between site and bloodstream (membranes)
ADME: distribution
getting the drug to the site of action.
ADME: metabolism
Any process that results in the chemical change in a drug in the body. May make drug less active, more active, or inactive. The major site of drug enzymatic metabolism is the liven.
Hepatic microsomal enzyme system
Nonspecific so it can work on many types of drugs. Especially, the cytochrome P450 family of enzymes
ADME: excretion
Most drugs are removed from the body via the kidneys. Water soluble leave through urine and non water soluble pass through GI tract.
ligand
a molecule which binds to a receptor
affinity
the extent to which the ligand/drug is capable of binding and remained bound to receptor.
drug active site?
synapse
Dose vs dosage
Dose is quantity of drug administered to body (mg/kg). Dosage is adminstration of drug per unit of time (4 times a day for 3 days)
efficacy
refers to the ability of a drug-receptor complex to produce a functional response. Ability to produce the maximum effect.
potency
- defined by its (effective dose) EC50 value
- measure of the ability of the drug to bind to its molecular target
EC50
- proportional to both efficacy and affinity
- concentration of agonist needed to elict half of the maximum biological response of the agonist
- useful for comparing the potency of drugs with similar efficacies
therapeutic index
- a measure of the relative safety of a drug
- therapeutic ration: LD50/ED50
- the greater the ratio the safer the drug
- LD= toxicity
- ratio must be at least 10 for a drug to be considered safe
agonist
activates receptor
competitive antagonist
prevents agonist from binding to receptor. No drug action/effect.
noncompetitive antagonist
inhibited receptor interaction. changes shape of receptor for drug.
4 C’s of addiction
- craving
- loss of control of amount or frequency of use
- compulsion to use
- use despite consequences
features of drug addiction
- genetic, psychosocial, and environmental factors
- progression of acute drug use to development of drug seeking behavior
- vulnerability to relapse
- decreased ability to respond to naturally rewarding stimuli
physical dependence
-tolerance to a drug oftern occurs and negative physcial withdrawal symptoms
what is the reward pathway?
VTA-> NAc-> Cortex
Why have a reward system?
- faster than conditioning
- allows for prediction and planning
- is proactive, not just reactive
- natural rewards of food, water, sex, and social contact
models of addiction
biopsychosocial, physical dependence, and psychological dependence (positive reinforcement)
comorbidity
If a person exhibits one type of behavior, they are much more likely to exhibit one of the others (either now or in the future).
drug trigger
the sight or thought of drug use can actually begin to trigger the effects
tolerance (physical dependence)
normal amount of drug has less effect. Need more of the drug to achieve same effect.
withdrawal
- bad things happen when drug administration ceases
- due to tolerance (in response to the chronic presence of a drug)
- When drug is removed the compensatory mechanisms are exposed, and an imbalance results.
- characterized by unpleasant symptoms when an individual tries to cease drug use
types of tolerance
- functional (pharmacodynamic)
- metabolic (pharmacokinetic)
- cross-tolerance
functional tolerance
- changes in mechanisms that cause drug effect at the cellular level (each drug has an action that causes behavioral effect, so changing properties effects can change)
- causes compensation for the continued presence of the drug
- brain seeks homeostasis (pharmacodynamic)-body wants to go back to it’s normal state
changes with functional tolerance
- receptor changes (density and sensitivity)
- transmitter changes (production and release)- could be changes in the dopamine receptor
metabolic tolerance
- drug disposition tolerance
- altered bioavailability of the drug
- increased drug metabolism***
- increase liver CytP450 enzymes and increase breakdown
- drug doesnt reach the brain as quickly then
cross tolerance
- exposure to one drug leads to a diminished effect in another drug
- especially dangerous when you consider the narrowing of the margin of safety and harmful side effects
basic characteristics of withdrawal
- often reverse effects from drug, has both psychological and physical effects, can cause death, a sign of physical dependence
reward
positive reinforcement that biases behavioral choice towards the rewarded behavior
punishment
negative reinforcement that biases behavioral choices away from the punished behavior
avoidance
reinforcement is the absence of punishment, although no reward is given
Other terms for CNS depressants
sedatives, tranquilizers, hypnotics, sedative-hyponitcs
CNS depressants
alcohol, barbituarates, benzodiazepines, GHB, inhalants
types of alcohols
- methanol or wood alcohol (toxic): metabolized into formic acid and formaldehyde
- isopropyl or rubbing alcohol (toxic): metabolized into acetone
- ethyl alcohol is the good one
Alchohol (intramuscular)
-Can reduce the intensity of spasms (used to treat spastic cerebral palsy in children). The anti spastic periods of time become more brief with every subsequent injection. Dosing with injections causes no adverse effects.
alcohol (intravenous)
Has been used for intravenous therapy for its analgesic and anesthetic qualities (can remove bacteria and reduce pain)
alcohol (inhalation)
- AWOL
- vaporized alcohol where they use dry ice or heated alcohol. Alcohol gets into the bloodstream very quickly and it’s easy to overdose. (little regulation)
acetaldehyde
this chemical will make you feel ill if it accumulates to a high enough concentration
zero-order kinetic metabolism (alcohol)
only break alcohol down at .5L per hour rate. doesnt change depending on amount of alcohol consumed.
What NT systems does alchohol affect?
GABA, Glutamate, dopamine, opioid
GABA and alcohol
Inhibitory, ionotropic Cl- channels, responsible for the depressant effects of alcohol
Glutamate receptors and alcohol
Inhibits NMDA receptors which is an excitatory channel, opens Ca2+ channel, responsible for memory deficits
Blood alcohol concentration (bac)
refers to number of grams of alcohol in the blood per 100ml of blood. Expressed as a percentage
what affects addiction (quiz question)
how quickly the drug gets into the blood system
how efficacy curves change:
up and down movement
Bi-phasic nature of alcohol
lower levels of alcohol have stimulation and higher levels have sedation effect
acute vs chronic
short vs long term
Wernicke-Korsakoff syndrome
- cell loss in thalamus and hypothalamus (&cortex)
- symptoms: confusion, disorientation, tremors, poor coordination, and memory disorder
- progressive and irreversible (long term changes and permanent)
- slowed by thiamine treatment
acute tolerance of alcohol
- tolerance over one sitting of drinking
pharmocokinetic tolerance of alcohol
- metabolic
- drug disposition tolerance (increased metabolism)
pharmocodynamic tolerance of alcohol(glutamate induced withdrawal)
Glutamate release is increased at around 10 hours after withdrawal. The time course of glutamate release closely matches the time course of withdrawal symptoms of alcohol.
behavioral tolerance to alcohol
Motor tasks after alcohol (introxicated behavior following alcohol consumption can be lessened to achieve an external reward)
