Lecture 1 – Introduction and Drug Classification
Defining pharmacology and psychopharmacology
Pharmacology: Discipline that examines the effects that drugs have on biological systems (including nervous and non-
-How the body reacts to drugs
-Different ways it interact
-How drugs act on other biological systems (pharmacokinetics)
-Different from pharmacy (more medical)
Psychopharmacology: Discipline that examines the effects that drugs have on behavior and mental processes, including
cognitions and emotions.
-Interact with the nervous tissue
What distinguishes a course in psychopharmacology from one in pharmacology?
-Focus on the brain and nerve cells distinguishes course in pharmacology
Definition of Drug: Miriam Webster Dictionary:
1. A substance used in a medication or in the preparation of medication.
2. A substance intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease.
3. Something and often an illegal substance, that causes addiction, habituation, or a marked change in consciousness.
4. A substance that affects the structure or function of the body.
Drug: A substance or chemical that, when injested/injected for the purpose of altering biological function, affects one or
more biological processes.
-Different meanings no fixed definition
-Other things also affect the structure and function of body like food, minerals, etc. but they are not considered drugs
Psychoactive Drugs: Chemicals that induce psychological effects by altering the normal biochemical reactions that take
place in the nervous system (Grilly and Salamone, 2011)
-Psychoactive drugs: largely mimic endogenous substances but outside the normal range
A Historical Perspective
- Humans have used drugs for the purposes of altering mood and behaviour for thousands of years.
- What would be some examples of ancient practices of drug use in recreational or religious settings?
- What would be some examples of early usages of drugs in pharmacotherapy?
- LSD or Esther
- A revolution in psychopharmacology was observed in the mid-20 century.
- What inspired this revolution?
- Discovery of a drug called Chlorpromazine for the treatment of Schizophrenia.
- Chlorpromazine (a.k.a. Thorazine) was used to treat schizophrenia not just to sedate those patients. There was a
new conceptualization of mental illness that it could actually be treated.
- Other early contributors to the revolution in psychopharmacology included:
o Lithium -There were concerns that it was too toxic but with more studies, lithium became the drug of
choice to treat mental disorders o LSD -was used to treat alcohol dependence and also to induce psychosis. LSD was used to trigger psychosis
in experiments to test chlorpromazine.
- Most individuals in society, at one time or another, use psychoactive substances recreationally.
- What are some examples of commonly used, non-illicit recreational drugs?
Non- Illicit Drugs: caffeine, alcohol, OxyContin, and nicotine
- What are some examples of illicit recreational drugs?
Illicit Drugs: heroine, marijuana, cocaine
There is a high percentage of illicit drug use in society today.
Common Drug Classification Strategies
1. Classification by molecular structure
2. Classification according to activation in the CNS (stimulants vs depressants)
3. Classification according to primary medical use
4. Classification by basic neurochemical action
5. Classification by schedule of control
New Drug Development
- Sources of drug discovery:
1. Natural resources e.g., Soil, plants, sea
- natural resources are major source of drug development in the 20th-century
- microbes with disease fighting properties eg: penicillin
- tech advances allow us to tap into the sea to find treatments and drugs eg: cancer fighting agents
2. Biochemical synthesis
-neurotransmitter discovery, drugs with high selectivity, genetic engineering using the genome
-Discovery of new drugs occurs in 1 of 3 ways:
1. Rediscovery of ‘folk’ usages of various naturally occurring products. e.g., willow bark for aches and fever
discovered by Hippocrates and used by natives the reason willow bark works is that it contains salicylic acid
which is now used to make into aspirin (acetylsalicylic acid)
2. Accidental observation of an unexpected drug effect. e.g., ibogaine which is an alkaloid found in Africa to treat
hunger and fatigue and was accidentally discovered to completely stop herione addiction
3. Synthesizing of known or novel compounds. e.g., benzodiazepine agonist (valium) - Stages in the testing and marketing of a drug
1. Belief that a particular compound has clinical value.
2. Preclinical and clinical studies. before drugs are approved they must be first tested on nonhuman animals and
then undergo human testing
3. Licensing and marketing approval. then allowed to market if the drug is approved
4. After-marketing evaluation of clinical use, particularly short-term and long-term effects. evaluate for side
- Issues to be considered in clinical and preclinical trials:
1. Relevance/generalizability of animal studies to humans.
Generalizability: Applicability of a research finding from one setting or group of research participants to others.
- presence of the drug in body and environmental effects of the drug
2. Ethics of drug research in humans.
The Nuremberg Code - due to biomedical research done in Nazi Germany, the Nuremberg Code was created where
the persons permission needs to be given