Addiction studies (Graduate Student)
L Anderson
4-1PharmacologyAS2000-5000SU2021.pptx1
Industry-funded Tufts Center for the Study of Drug Development, manufacturers have posited that it costs about $2.6 billion dollars to develop a new drug.
The cost, according to consumer advocacy groups like Public Citizen, is actually closer to $161 million—an amount manufacturers can sometimes make back within days of introducing a product.
Federal government funds 84 percent of initial drug research, and charitable organizations additionally contribute on top of that.
*A recent study showed that all 210 of the new drugs approved by the FDA between 2010 and 2016 were funded by the National Institutes of Health.
Big Pharma’s Big Lie
Reference
Cleary, E. G., Beierlein, J. M., Khanuja, N. S., McNamee, L. M., & Ledley, F. D. (2018). Contribution of NIH funding to new drug approvals 2010–2016. Proceedings of the National Academy of Sciences, 115(10), 2329-2334.
While the drug industry purports to focus on cures for Alzheimer’s, rare cancers, and other neglected diseases, it actually prioritizes drugs for non-life-threatening conditions like male baldness.
78% of patents recently approved by the FDA were for medications already on the market
1 % of R&D funding was allotted to rare and neglected diseases
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High drug prices reflect the value of a drug; if a drugs cures a condition, it will allow patients to avoid the costs of future treatment.
Myth or Reality
Myth: Many high-cost drugs help individuals manage chronic conditions and are not cures.
Most drugs dispensed are generic, and only the prices of brand-name blockbuster drugs are increasing dramatically.
Myth: Drug manufacturers have increased the prices even for older, generic drugs that are widely used.
Myth: Eight out of 10 major drug manufacturers spend more on advertising than on research and development
Myth: Big Pharma has gamed the system by “evergreening” patents, colluding to fix prices, and
engaging in “pay-for-delay” schemes
High prices are necessary to fund the development of new drugs
Myth: it took an act of Congress, known as the Orphan Drug Act, nearly 35 years ago to get drug manufacturers to be
willing to develop drugs for people suffering from rare diseases
Without special incentives, drug manufacturers would be unable to afford to develop drugs for rare diseases and conditions.
The pharmaceutical industry is interested public health over profit
A Brief Introduction to the Science of Pharmacology
This Photo by Unknown Author is licensed under CC BY-NC-ND
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What is “pharmacology”?
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“The science concerned with drugs, their sources, appearance, chemistry, actions and uses.” (Farlex Partner Medical Dictionary, 2012)
There are two broad divisions of pharmacology:
Pharmacokinetics (PK) refers to the movement of drugs through the body.
Pharmacodynamics (PD) refers to the body’s biological response to drugs.
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Efficacy
Safety Profile
Route Of Administration
Route Of Elimination
Dosing Frequency
Cost
What are some considerations when prescribing or taking drugs?
**Risks and benefits of the drug should always be assessed; every drug poses some risk
(The ability to produce the desired or intended result)
Also, one’s . . .
Age
Sex
Other Medical Problems
Likelihood Of Pregnancy
Other Genetic Determinants
Pharmacology and Drugs of Abuse
Drugs of abuse work by changing the biological function of target cells through chemical action.
They strengthen or weaken a potential that already exists in the body.
Drugs of abuse target the cells of the central nervous system.
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Prime Effect and Side Effect
Prime Effect ~ the desired effect the drug is expected to have.
Side Effect ~ the unwanted effects of the drug.
Side effects intensity can vary from mild and to severe – even life threatening.
?
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Name a medication you have used. What was the desired effect? What was the undesired side effect?
Can you name a desired effect and unwanted side effect from an illicit drug?
Method (Route) of Administration (how it is taken)
Influences the intensity of the drug’s primary and side effects.
The method of taking the drug impacts . . .
The speed with which the compound begins to have an effect (speed of onset)
The way the compound is distributed throughout the body
The intensity of its effects
The speed of onset of the side effects
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Method of Administration (how it is taken)
Inhalation (Inhaling)
Intravenous Injection (Into the vein)
Intramuscular Injection (Into the muscle)
Subcutaneous Injection (Under the skin)
Intranasal (Snorting)
Ingesting (Oral)
Transdermal (Through the skin)
Sublingual (Under the Tongue)
Rectal (In the Rectum)
Debra Hanselman, LMSW, MHA 1500 Fall 2018
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Do you remember which mode of administration has the fastest onset? (7 – 10 seconds) Which mode of administration, other than transdermal, has the slowest onset? (20 – 30 minutes)
Debra Hanselman, LMSW, MHA 1500 Fall 2018
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The Process: From Use to Elimination
The chemical must be . . .
Absorbed into the system
Distributed throughout the cells of the body
Transported through the blood system
Water-soluble chemicals intermix with blood plasma (Ex. Alcohol)
Lipid-soluble chemicals bind to molecules in the blood and become concentrated in the brain (Ex. Marijuana)
*Biotransformation is the body’s process of filtering dangerous chemicals (Metabolized by kidneys, lungs, sweat glands, liver, gall bladder and bile ducts)
*Elimination is the process of removing the chemical from the system.
Drug Half-Life
Elimination half-life – the time the body needs to eliminate 50% of a single dose of a chemical. Also known as t ½
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Why is this important?
Drug Dosages
Effective Dose – desired response of the drug in the system
Overdose – too large a dose alters the body’s functions and can lead to -
Lethal Dose – too large a dose alters the body’s function so much the user dies
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*LD50 is the dose which causes death in 50% of the participants.
Therapeutic Threshold and Peak Effects
Therapeutic threshold is the minimal level at which the drug is effective
Peak Effects is greatest effect the drug will deliver
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Site of Action
Where the chemical carries out its main effects.
Psychoactive chemicals carry out the action in the central nervous system (CNS)
Thus psychoactive chemicals can become drugs of abuse and dependence
The CNS has approximately 100 billion neurons
One neuron releases chemical molecules (neurotransmitters) to transmit the brain chemical across the space (synapse) to the receiving neuron.
There are over 150 brain chemicals that function as neurotransmitters
Only some are affected by drugs of abuse.
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Neurotransmitter Reuptake
The process where the releasing neuron takes back some of the chemical that did not make it across the synapse to be reused.
Neurons can “fire” (send brain chemicals) up to 200 times per second.
Reuptake makes it possible for the neuron to use less energy because it can make less new neurotransmitter chemicals.
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Tolerance
Tolerance to a chemical means a shorter duration and less intensity of the drug effects after repeated use.
In other words – it take more of the chemical than before to get the desired effect.
Therefore – one must use more of the chemical to get the desired effect.
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Types of Tolerance
Metabolic Tolerance – The proficiency of metabolizing the chemical
Behavioral Tolerance – Behavior of the individual indicates a lower dose despite having used much more of the chemical.
Cross Tolerance – When two chemicals target the same neuron receptor sites the receptors will become less sensitive to one of the chemicals (so they don’t work as well)
Reverse Tolerance – When lower doses of the chemical produces the same effect as higher doses taken before … example?
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Agonists and Antagonists
Agonists – The drug activates a receptor site by mimicking or enhancing the actions of a natural neurotransmitter
Antagonists – Bind to the receptor site without activating it (blocking transmission)
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Blood Brain Barrier
Blood actually touching the neurons of the brain is not good for it and cause a great deal of harm – even death.
Therefore, blood capillaries are surrounded by a thin layer of cells (screen) that separate the brain from direct contact with the circulatory system, yet allows molecules such as glucose, iron, and vitamins to enter the neurons.
This protects the brain from toxins or micro-organisms that would destroy it.
Debra Hanselman, LMSW, MHA 1500 Fall 2018
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The Blood-Brain Barrier
A network of blood vessels and tissue that is made up of closely spaced cells and helps keep harmful substances from reaching the brain.
Bioavailability?
Epidemiology
Epidemiology is the researched study, analysis, and outcomes of the distribution (who, when, and where) and determinants of health and disease conditions in defined populations.
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Can anyone give an example of an epidemiological study or suggest one?
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Pharmacotherapy is the treatment of a disorder or disease with medication.
In the treatment of addiction, medications are used to . . .
reduce the intensity of withdrawal symptoms,
reduce alcohol and other drug cravings, and
reduce the likelihood of use or relapse for specific drugs
How/why is this information important within the context of AOD-related fields?
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THERE ARE 3 PRIMARY CLASSES OF MEDICATIONS TO TREAT SUBSTANCE USE DISORDER
Agonists
Antagonists
Mixed Agonist-Antagonists
Heroin, oxycodone, methadone, hydrocodone, morphine, opium
Naltrexone & naloxone
Buspirone & buprenorphine
References
Doweiko, H. (2015). Concepts of Chemical dependency. ninth edition. Cengage learning.
Farlex Partner Medical Dictionary © Farlex 2012
The Free Dictionary On-line. https://medical-dictionary.thefreedictionary.com/pharmacology
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
The Brain – Lesson 2 – How Neurotransmission Works. (2011). TheProfessorTed. YouTube video.
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