Module 1 - PHAR 100 Flashcards
(141 cards)
1
Q
Humans have used drugs since before recorded history. Early written records from __________ and ____________ provide a glimpse of the ancient traditions of drug use. Although a few useful drugs (eg. opium) were identified over __________ years ago, the majority of clinically useful drugs have been developed over the past _______ years with the advent of experimental biological sciences, including ______________.
A
China, Egypt, 2000, 250, Pharmacology
2
Q
What are the three types of influences which have shaped modern pharmacology?
A
Ancient Civilizations
Poisons
Religion
3
Q
What are the three ancient civilizations discussed in class?
A
Ancient Greece
Ancient Egypt
Ancient China
4
Q
In the year 380 BCE, __________________, a pupil of ________________, wrote a textbook on the therapeutics that included ___________.
A
Theophrastus, Aristotle, opium
5
Q
Opium is obtained from the…
A
Opium poppy (Papaver somniferum)
6
Q
___________, a pharmacist working in Germany in 1803, isolated crystals of _____________ from opium and tested the pure substance on himself and three companions, discovering its _________________ capabilities
A
Serturner, morphine, pain relieving
7
Q
What percent of morphine is contained in opium?
A
10%
8
Q
What is morphine named after?
A
Morpheus, god of dreams
9
Q
What does morphine do?
A
Relieves great intensity pain. In contrast, acetylsalicylic acid and acetaminophen only relieve mild to moderate pain.
10
Q
What percent of codeine is contained in opium?
A
0.5%
11
Q
What drug contains codeine?
A
Tylenol-3 (prescription drug)
12
Q
Ancient Egyptian history was recorded on documents called …
A
papyri
13
Q
It was discovered that one of these papyri, the … Papyrus dating from the year 1550 BC, was intended to be a …
A
Ebers, textbook of drug use for medical students
14
Q
The Ebers Papyrus contains many true observations on the use of drugs, particularly on …, which are drugs used to cause bowel movements. One of the drugs recommended for use was … still used today!
A
purgatives, senna
15
Q
The earliest record drug experiments are those emanating from …. in the year 2700 BC. It is reported that emperor …. classified all drugs according to …
A
China, Shen Nung, taste
16
Q
The drug … was classified as “medium drug”. This drug was widely used in Chinese medicine for coughs, influenza, fevers.
A
Ma Huang
17
Q
In modern era, …. has been isolated from Ma Huang. This has been used to treat… and a derivative is used as a …
A
Ephedrine, asthma, decongestant
18
Q
What are two examples of poisons that have led to the development of drugs?
A
Curare
Ergot
19
Q
Curare, a plant-derived drug, was historically used by Indigenous Peoples in various regions of the… in …
A
Amazon rainforest, South America
20
Q
How was curare used as a poison?
A
Indigenous Peoples of the Amazon dipped their arrows in curare to use as a poison. Curare acted upon the voluntary muscles of the animal, causing paralysis and eventually death by respiratory paralysis.
21
Q
How was curare used as a drug?
A
Used by anesthetists during surgery. By giving a small dose, muscle relaxation was achieved. Structure of curare has been modified to make the drug safer, and these newer derivatives of curare are used by anesthetists today.
22
Q
What does ergot come from?
A
Poisonous fungus that grows on the heads of rye, particularly during wet seasons.
23
Q
In the Middle Ages, ergot was ground together with rye, thereby finding its way into… As a result, terrible epidemics occurred and 250 years ago one of these epidemics killed 20 000 people in one region of Russia.
A
bread
24
Q
What three systems does ergot poisoning effect?
A
Nervous
Cardiovascular
Reproductive
25
How does ergot impact nervous system (3)?
Ergot targets nervous system upon entering body. This results in symptoms such as mental frenzy, hallucinations, and convulsions.
26
How does ergot impact the cardiovascular system?
Constriction of blood vessels leading to finders, toes, and limbs being starved of blood supply, and resulting in a burning sensation, Over time, the limbs become black and gradually die, and in extreme cases, may even fall off.
27
How does ergot impact the reproductive system?
Can cause violent contractions of the uterus, which is part of the female reproductive system.
28
As early as the 16th century, some midwives recognized that small amounts of ergot could be useful in... In the 1800s, physicians used ergot to expedite... However, if not used appropriately, it could result in death.
hastening labour, lingering labour
29
What are two compounds derived from ergot that have pharmacological uses?
Ergotamine and ergonovine
30
What does ergotamine treat?
Migraines
- migraines caused by pulsation of arterial blood vessels that carry blood to the head
- ergotamine constricts these blood vessels, reducing the amplitude of the pulsation
31
What does ergonovine treat (2)?
Once used to hasten birth, however, no longer used for this purpose, as force of uterine contractions may be too strong and the mother may be injured by too rapid delivery of the child. It can be used to arrest uterine bleeding after childbirth.
32
In ancient societies, medicine men acted as both ... and ..., resulting in therapy being heavily influenced by both religion and ...
physicians, priests, magic
33
In most parts of the world, plants containing intoxicating substances were used by medicine men in order to alter the state of .......... and facilitate .............
consciousness, communication with their gods
34
In Mexico, the ... cactus was widely used to achieve a ... state.
peyote, mystical
35
The Peyote cactus contains the potent substance .... which causes..., ..., and ... similar to that experienced with LSD.
mescaline, hallucinations, feeling of well-being, and distortion of perception
36
What is a drug?
Any substance received by a biological system that is not received for nutritive purposes, and which influences the biological function of the organism. Biological agents, chemicals, herbal products are considered drugs.
37
What percent of drugs used today are derived from plant sources?
25%, with the active substances being purified and then potentially modified to be either more effective or less toxic.
38
The ... century heralded the era of chemical synthesis and most drugs discovered or introduced into therapy were small molecules obtained by chemical synthesis in the laboratory.
19th
39
What are two major categories of drugs discovered throughout history?
Drugs that act on the brain
Drugs that act against infectious disease
40
Drugs that act on the brain ... normal chemical signalling in the brain. An example is ..., one of the most potent hallucinogenic drugs.
alter, LSD
41
Who discovered LSD? How? What is it similar in structure to?
- Albert Hofman (worked for Swiss pharmaceutical firm)
- wanted to synthesize drug based on components of ergot
- in 1943, synthesized LSD, similar in chemical structure to ergotamine and ergonovine
42
The discovery of the psychedelic effects of LSD supported the idea that ....
certain mental illnesses may be due to the production of potent substances in the brain that could produce psychic disturbance
43
Is LSD prescribed to people?
- No, classified as a controlled substance in 1970s
- Recently, some evidence indicates that derivatives of psychedelic compounds like LSD may be effective in treating certain mental illnesses (ex. depression, anxiety, addiction)
44
What's an infectious disease?
Disease caused by an organism (ex. bacteria, viruses, fungi, parasites)
45
What was the order of drugs created that target infectious disease? 1900s, 1930s, 1940s, 1950s
1900s - Organoarsenicals
1930s - Sulfa Drugs
1940s - Penicillin
1950s - Streptomycin
46
How do organoarsenicals work? What do they cure?
Complex of arsenic and organic molecules, selectively bind to parasites. Lead to cure for syphilis in early 20th century.
47
Who created organoarsenicals?
Paul Ehrlich
48
Who discovered sulfa drugs?
Gerhard Domagk
49
What do sulfa drugs treat?
Bacterial disease
Lead to development of antibacterial compounds
50
Who discovered penicillin?
Alexander Fleming
51
When was penicillin used? What does it treat?
Second World War
Used against Gram-positive bacterial disease (diptheria, staphylococcus)
52
Who discovered Streptomycin?
Selman Waksman
53
What does streptomycin treat?
TB, Gram-negative disease (cholera, E coli)
54
What's Gram-positive vs Gram-negative?
Gram-positive: have thick cell wall, no outer membrane
Gram-negative: have thin cel wall, and outer membrane
55
What are the five steps of drug-development? How long are each?
3-6 Years:
Basic Research & Drug Discovery
Preclinical Trials
6-7 Years:
Clinical Trials
0.5-2 Years:
Health Canada Review & Manufacturing
Continuous:
Post-Market Surveillance & Phase IV Clinical Trials
56
What are the two parts of Basic Research and Discovery of Target?
1) Identification of the Target
- could be receptor that, when activated, causes relief of pain
- once compound binds well to target, studied to determine pharmacological effects at molecular, cellular, organ and whole animal level
2) Studying the Target
- if compound shows promise in initial studies, identified as lead compound, and will enter safety and efficacy studies
57
After the drug target has been discovered and sufficiently studied, the drug enters preclinical studies... are these studies conducted on HUMANS?
No. They range from molecular and cellular studies to tissue and whole animal studies.
58
What are the two main categories of preclinical studies?
Pharmacology
- determine detailed mechanism of action of drug
Toxicology
- potential risks or harmful effects of the drug
- studies will be performed to look at acute toxicity, chronic toxicity, and effects on reproductive, carcinogenic, and mutagenic potential
59
Which is more expensive? Pharmacology or toxicology studies?
Toxicology
60
What are initial steps a manufacturer must take before testing a new drug on humans in a clinical trial (3)?
1) Proof of Safety
- must submit proof of safety and efficacy of drug in several animal species to government regulatory agency in the particular country concerned (Health Products and Food Branch, and FDA)
2) Methodology of Proposed clinical trial in humans
3) Investigation - evaluated by qualified scientists in regulatory agency. If satisfied with submission, permission will be given for highly qualified investigators to begin investigation in humans
61
Do animal studies always predict drug behaviour in humans?
No
62
How many compounds make it through preclinical testing into clinical trials?
5-30
63
Of these, many drugs make it to phase 3 trials?
1-2
64
What do phase 1 clinical trials evaluate? Who are phase 1 clinical trials tested on?
- Absorption, distribution, elimination, and adverse effects of new drug.
- These trials test one or two doses of the drug to determine tolerability
- Efficacy is not assessed here
- 20-80 healthy volunteers
65
What is the point of phase 2 clinical trials? Who is involved here?
- seeing if drug is effective in treating condition for which it is recommended
- 100-500 people with disease
- pay attention to safety
66
What are phase 3 clinical trials often called?
Randomized Control Trials
67
How many people are in phase 3 clinical trials? What is the goal of them? How long are they? Location? Cost?
- 1000+ people
- Determine how safe and effective drug is compared to no treatment or current recommended therapy
- Longer than phase 2 (months to years)
- Multi-centered
- one million to 50 million
68
What are the three stages of phase III clinical trials?
Enrolment
Treatment Allocation
Results
69
Describe the Enrolment stage.
Target population - group of patients for whom the drug is intended
Study population - subset of target population that meets required criteria (inclusion/exclusion and consent)
Inclusion/Exclusion defines who can be included in study. Eliminates other variables other than drug under study. Specifies level of severity. Common comorbidities included to represent target population.
Consent - before able to participate in trial, informed consent must be obtained. Document written in non-scientific language that outlines the purpose of the study, procedure that will be used, potential risks and benefits. Reviewed by independent Institutional Ethics Review Board to protect rights of participants. Participants can revoke consent at any time without penalty.
70
Describe the treatment allocation phase.
Double Blind Design - neither investigator nor study subject aware of treatment
Randomization - assigned by computer-generated system at random to ensure confounding variables evenly distributed
Control - efficacy and safety of experimental has to be compared to control drug (either placebo or gold standard)
Placebo - no active drug, but identical in appearance, colour, taste, and administration to active drug (fake drug). Placebo response can be as high as 40% in sick, anxious patients.
Gold Standard - accepted by medical community as best available treatment. Unethical to withhold treatment if one exists.
71
Describe results.
Outcome of trial measures how much drug worked in each participant.
Compliance (can be as low as 50-60%), quality of life and statistics measured.
72
What happens after successful completion of initial phase 3 trials?
Manufacturer will submit to regulatory body a new drug application containing detailed results of the clinical trials. (Health Canada)
- reviewed by regulatory scientists, if drug is effective with acceptable toxicity, will be granted approval
73
Manufacturers come up with a drug name (...) and a ... name for the drug.
generic, brand
74
If a drug undergoing development shows promise and a manufacturer wishes to place it on the market, a generic name is selected. Around the same time, manufacturer will apply for a patent with a brand name for the drug, which will give the company exclusive rights to market the drug for ______ years.
20
75
The 20-year life of a patent begins when the patent is filed, usually during the preclinical development phase. Factoring in the length of clinical trials, effective patent life of a drug is in the range of ... years.
10-12 years
76
What happens after a patent on a drug expires?
Other manufacturers can make copies of the original brand name drug, and sell it under their own brand name.
77
What is bioequivalence?
Original brand name and any generic versions will contain identical active ingredient, in same amount, and usually same dose. Strict regulations to ensure marketed drugs as effective as original brand name.
78
How do they check bioequivalence?
- comparative bioavailability study conducted --> compares blood levels after administration of both the original brand name drug and new brand name/generic drug to healthy volunteers under controlled conditions
79
What is post-marketing surveillance or phase 4 clinical trials?
Risks that are delayed or less frequent than 1 in 1000 administrations may be missed in phase 3 clinical trials. Surveillance of effects of drugs is required after drug released for general use.
80
When considering a drug's action, one needs to look at several factors (4):
1) Drug targets
2) Drug response
3) Efficacy and potency
4) Therapeutic range
81
Are all targets for drugs receptors?
No
82
What are receptors?
Molecule or complex of molecules located on outside/inside of cell with a regulatory or functional role in organism.
83
Do many copies of the same receptor exist within a cell?
Yes
84
What are receptors bound to and activated by?
Endogenous ligands - substances ordinarily found in body (ex. hormones and neurotransmitters)
85
What is the significance of the location of receptors?
- determines where a drug will act and whether the response that results from the drug-receptor interaction is beneficial or detrimental
ex. opioid receptors in brain cause pain relief, activation in GI tract causes constipation (adverse effect)
86
What are examples of other drug targets?
Chemical Reactions - antacids neutralize stomach acid through acid-base neutralization
Physical Chemical Forces - cholestyramine chemically binds to bile acids in GI tract to prevent reabsorption and increasing elimination of bile salts used to make cholesterol
87
Most drugs mimic the action of, or block the effect of, the endogenous ligand at the receptor. Drugs that bind to and stimulate a receptor are called ... and drugs that bind to but block the response at a receptor are called ...
agonists, antagonists
88
Generally, the intensity of the pharmacological effects produced by a drug ... in proportion to the dose. This is called...
increases, dose-response relationship
89
What happens at low doses of a drug?
Very little response observed, not many receptors activated
90
What happens at threshold?
- more and more receptors activated until desired response seen
- threshold exists, where a certain number of receptors need to be activated before an effect will be seen
91
What happens at therapeutic dose?
Once this threshold is reached, a small increase in dose results in a large increase in response.
92
What happens at maximal effect?
- increase in response is not indefinite, our bodies have a maximal effect
- once maximal effect reached, continuing to increase the amount of drug will have no further increase in therapeutic response
93
What is on Y-axis of dose-response curve?
Effect of drug is on y-axis and plotted on a linear scale. Maximal response the body can produce is set at 100%.
94
What is on X-axis of dose-response curve?
Dose of drug, plotted on logarithmic scale
95
What is ED50?
Dose of drug that will result in 50% of maximal effect. Can be interpreted as dose of drug effective in 50% of population.
96
What is efficacy?
Maximum pharmacological response that can be produced by a specific drug in that biological system.
97
What is potency?
Dose of drug required to produce a response of a certain magnitude (usually 50% of maximal response for that drug).
98
Clinically, which is more important? POTENCY or EFFICACY
Efficacy
99
What is therapeutic range?
- keeps blood concentration of a drug above the minimum concentration that produces the desirable response, but below concentration that produces unacceptable toxicity
100
What are pharmacokinetics?
Movement of a drug into, through and out of body.
101
What are the three major routes of administration?
Topical
Enteral
Parenteral
102
What are the three types of topical administration? What are pros/cons?
On the skin - to treat skin conditions (eczema) --> can be absorbed and produce systemic effect
Through the Skin (transdermal) --> for absorption into general circulation (ex. nicotine patch) --> convenient, delivers steady drug supply, bypasses enzymes of stomach, intestine, liver. Can be $$ and cause irritation
Inhalation - both local and systemic effect
- quantities of drugs are small and often less than required for a systemic effect, thus avoiding toxicity associated with oral administration. Requires proper use by patient
103
What is the onset of action and bioavailability of topical administration?
Rapid to slow
5% to 100%
104
What are three methods of enteral administration? Pros/cons
Enter blood through GI tract.
Mouth
- 90% of drugs taken this way
- most convenient, least expensive
- non-invasive, self-administered
- variable absorption based on intestinal motility and disease
Rectum
- systemic or local effect
- can be used in patients who are nauseated or vomiting, or as a less invasive route for those who are comatose
- digestive enzymes of stomach and intestine bypassed
- limited medications available
- slow, incomplete administration
Sublingual/Buccal
- enzymes of stomach, intestines, and liver bypassed
- not all drugs adequately absorbed here
- may be swallowed and behave as if taken orally
105
What are the onset of action and bioavailability for enteral?
30-100%
Mouth - Slow (30 min - 1 hour)
Rectum - Slow and incomplete
Under tongue - rapid (1-2 min)
In cheek - Intermediate (3-4 min)
106
What are the three parenteral administration routes?
Intravenous - placed directly in blood, can be used for drugs poorly absorbed.
- response is irreversible (highest risk for drug interactions)
- human resources required
- preparations must be free of fever producing substances (pyrogens)
Intramuscular
- drug injected deep into a muscle
- volume of drug limited to 2-3 mL in an adult
Subcutaneous
- drug injected into deepest layer of the skin
- allows for modification of drug preparations to control timing of release of the drug from the injection site
107
What is the onset of action and bioavailability of parenteral routes?
Veins - 15-30 sec - 100%
Muscle - 10-20 min - 75-100%
Under the skin - 15-30 min - 75-100%
108
What are three methods of absorption?
Movement of drug from site of administration into blood.
1) Diffusion through aqueous pores (water soluble, small drugs)
2) Diffusion through lipids (for heavy drugs) - cross membrane
3) Active or carrier mediated transport. Drugs bind to carrier proteins or transporters, which carry molecules across a membrane. Move down concentration gradient, but can also be an active process requiring energy to move drug against concentration gradient.
109
What is distribution? Describe equilibrium. What does the rate of distribution depend on?
Movement of drug from blood to site of action and other tissues.
Most drugs reach all tissues regardless of target site of action. Concentrations of drug at sites of distribution are in equilibrium with its concentration in the blood. If concentration in blood drops below concentration at any distribution site, drugs will move from that site to blood to maintain equilibrium.
Rate of distribution depends on blood flow to that organ. More blood flow = more rapidly drug reaches that organ
110
Describe how distribution can result in termination of therapeutic effect of some drugs (ex. thiopental).
Administration: After intravenous injection, thiopental concentration is high in the blood and brain (high blood perfusion), causing the patient to fall asleep.
Distribution: Over time, the drug moves into muscle and fat (low blood perfusion), lowering its concentration in the brain.
Termination of Effect: As thiopental leaves the brain and redistributes into muscle and fat, the patient wakes up (typically within 15-30 minutes).
The drug remains in the body but is no longer effective in inducing sleep.
111
Describe drug metabolism (biotransformation). What is it? What are products of metabolism called?
Conversion of drug to different chemical compound to eliminate it.
Products called metabolites and are usually devoid of pharmacological action.
112
What must a drug be to be eliminated by kidneys?
Water soluble
113
Where does most biotransformation occur?
Liver
114
Where does some metabolism also occur?
Kidneys, intestines, lungs, skin, and most other organs.
115
Drug biotransformation reactions are divided into ...
Phase 1 and Phase 2 reactions
116
What are enzymes capable of biotransforming drugs? Where are high concentrations of this found?
P450s
High concentrations in liver
117
What is the purpose of a phase 1 reaction?
To add or unmask a functional group on the drug to prepare it for the addition of a large water-soluble molecule in the phase 2 reaction.
118
What is the purpose of a phase 2 reaction?
Add a large water-soluble moiety, usually glucuronic acid or sulfate, to the product resulting from phase 1 biotransformation, making the metabolite water-soluble for excretion by the kidney.
119
What does drug excretion involve?
Moving the drug and its metabolites out of the body. All body fluids will contain drugs and their metabolites.
120
What are five organs that help with excretion?
Kidneys - majority of drugs excreted here. Lipid-soluble drugs can be reabsorbed and enter blood again
Breast Milk - child can be exposed to therapeutic or toxic dose of drug
GI Tract - feces
Sweat & Saliva (can detect misuse this way)
Lungs
121
What is the half-life of a drug?
Time needed for liver and kidneys to remove half the drug from the body
122
What are different factors that contribute to variation in drug response... got especially over
Genetic - variability exist in receptors which drugs bind to and manner in which body handles and eliminates drugs
Environmental - exposure to certain chemicals can increase enzymes in liver responsible for biotransformation --> eliminate drug more rapidly
Other Disease States - alter manner in which drugs handled by body
Altered Physiological State - pregnant or elderly
Other Drugs Present - possible for one drug to change biological effect of another
123
The toxic effects of drugs can be divided into... (2)
Adverse Effects
Drug-drug and Drug-food interactions
124
What is an adverse effect?
Any effect produced by a drug in a patient that is not the intended effect
125
What are six examples of adverse effects (every under..)
- Extension of therapeutic effect (too much of drug in blood)
- Unrelated to Main Drug Action
- Allergic Reaction
- Withdrawal and Addiction
- Teratogenesis
- Adverse Biotransformation Reaction
126
What are four reasons why predicting adverse drug reactions is challenging?
Rarity of occurrence - chloramphenicol used for several years before it was realized that one in 50 000 patients experience fatal bone marrow damage
Length of usage - streptomycin can cause deafness if used for long time
Detectability in Animals - only appears when tested in humans (ex. headache, insomnia, nausea, and mental disturbances not readily picked up in animal testing)
Time Period Specificity - toxic effect may be unique to particular time period (ex. thalidomide produced abnormal limb growth in fetus)
127
How to calculate therapeutic index?
TI = TD50/ED50
128
The higher the therapeutic index, the ... the drug
Safer
129
What is TD50?
Dose of drug toxic in 50% of population
130
How can drug-drug interactions occur at three of ADME stages?
Absorption - can increase intestinal movement, speeding passage of second drug through intestine and decreasing contact with intestinal wall, decreasing absorption
Metabolism - can block inactivation of second drug in liver, increasing blood level and pharmocological effect of second drug
Excretion - can facilitate excretion of second drug by kidney, decreasing blood level and pharmacological effect of second drug
131
What are two examples of drug-food interactions?
Tyramine - found in well-matured cheeses and a variety of other foods. Capable of raising blood pressure and broken down by MAO. One antidepressant drug inhibits MAO, which means tyramine won't be broken down and raises blood pressure.
Grapefruit - inhibits inactivating enzymes, resulting in great amount of active drug being absorbed than would occur without grapefruit.
132
What is the largest part of the brain, which is very rich in neurons. Its function is sensory and motor coordination, mental processes, intelligence, memory, vision, judgment, thought, speech, emotions, consciousness. Neurons can be stimulated or depressed by drugs.
Cerebral Cortex (Cerebrum)
133
What is a region of the brain that integrates memory, emotion, and reward. This area of brain, along with hypothalamus, controls emotion and behaviour.
Limbic system
134
What are the functional units of the brain called? There are 90 billion in brain.
Neurons
135
What is the process where neurons are generated?
Neuogenesis
136
The connections between neurons is constantly being reshaped through what is known as...
Neuroplasticity
137
What are the three parts of a neuron?
Dendrites
Cell body - largest part, contains nucleus and surrounding cytoplasm, contains abundant pre-packaged neurotransmitters which can be secreted
Axon - single fibre that extends from cell body at synapse, continues to carry information away from dendrites and cell body by way of electrical impulses
138
What is synapse?
Junction between two neurons, where one neuron's axon ends and another neuron's dendrites or cell body begins
139
What is the passage of a signal from one neuron to another called?
Synaptic transmission/neurotransmission
Very rapid
140
What are the endogenous chemicals that transmit a signal between two neurons called?
Neurotransmitters
141
What are six different neurotransmitters and their receptors?
Glutamate - primary excitatory NT in CNS. Acts on glutamatergic receptors. Neurons that release glutamate are imporant for learning
Catecholamines - dopamine and norepinephrine are two.
Dopaminergic pathways involved in control of hormonal systems, motor coordination, and motivation and reward. Alterations in these dopamine-mediated motivation and reward systems are thought to be involved in addiction.
Norepinephrine - can bind to large number of receptor types, but main are alpha and beta. Activation of these receptors usually leads to excitation of the cell.
GABA - primary inhibitory NT in CNS. Neurons that release GABA and GABA receptors found in high concentrations in cerebral cortex.
Serotonin - hyperactivity of serotonergic system involved in anxiety, and hypoactivity implicated in depression. Some classes of CNS stimulants act by increasing serotonin at synapse
Acetylcholine - produces excitatory response in CNS. Two types of receptors bind acetylcholine (cholinergic receptors)
Nicotinic receptors & muscarinic --> involved in learning, memory, cognitive function. Can be stimulated by acetylcholine or muscarine. Drugs that block action of acetylcholine at these receptors produce amnesia. Loss of these cholinergic neurons associated with Alzheimer's disease.
Opioid Peptides - three types: enkiphalins, endorphins, dynorphins. Varying degrees of selectivity for three opiod receptors, mu, delta, kappa. All opioids interact with these receptors
