Download Chapter 1 An Introduction To Pharmacology

Chapter 1
An Introduction To Pharmacology
Pharmacology is the science dealing with interaction between drugs and living organisms.
Pharmacology (Gr. pharmakon - a drug or poison) pharmakon = drug, medicine, poison
Logia = study
Pharmacological study mainly include the following::
1.pharmacodynamics: actions of drugs on the body ("What the drug does to the body “)
2. pharmacokinetics: the fate of drugs in the body ("What the body does to the drug").
pharmacokinetics：
What the body does to the drug?
Absorption, distribution, biotransformation and elimination.
Pharmacodynamics:
What the drug does to the body?
Relationship between the concentration of drugs at its sites of action and the magnitude of effect
that is achieved, including the mechanism of action.
Pharmacological effect of informed procedure:
The Duties of Pharmacology
a. To explain the action and its mechanisms of drug,
b. to provide the theory for clinic and enhancing the drug efficacy.
c. To develop new drug and new indications of drug.
d. To explore the pathway of physio-, biochemic, and pathology of the cells.
Drug definition
A drug is a substance that can alter or influence the responsiveness of a biological system.
A drug is a chemical which is utilized for the diagnosis, prevention, cure or amelioration of
an unwanted health condition (definition by FDA).
Most of drugs are Xenobiotics (Gr. xenos - stranger) chemicals that are not synthesized by
the body, but introduced into it from outside.
1(Drugs): prevention, treatment, diagnosis of diseases of chemical substances.
Prevention:
rickets:
Adequate vitamin D prevents the development of bone diseases such
as rickets,
Treatment:
Diagnosis: Example:
(A) In gastrointestinal angiography examination, barium sulfate oral or enema is commonly used
to diagnose gastrointestinal diseases
(2) histamine: for gastric secretion function tests: In the early morning fasting, subcutaneous
injection for the 0.25 ~ 0.5mg after tests gastric juice, as there is still no gastric acid secretion, can
be judged to be true acid deficiency. Most pernicious anemia and cancer patients have a true
achlorhydria or too few patients.
Drugs can be classified into following categories:
1. replace physiological inadequacies, Insulin
2. cure disease, Antibiotics
3. treat symptoms, Antihypertensives
4. prevent disease, Bacterin
5. alter mood or behavior (including Social drug), Alcohol, cocaine, opiate
Modern medicine relies heavily on drugs as the main tool of therapeutics. Other therapeutic
procedures such as surgery, are also important, of course, but none is so widely applied as
drug-based therapeutics.
The Main Branches of Pharmacology
Clinical pharmacology
Biochemical pharmacology
Molecular pharmacology
Immunopharmacology
Cardiovascular pharmacology
Neuropharmacology
Pharmacogenetics
Chemotherapy
The relationship between drug concentration and biological response.
Drug action over time.
Factors affecting absorption, distribution, binding, metabolism, and elimination of chemicals
Structure-activity relationships.
Biological changes that result from repeated drug use: tolerance, addiction, adverse reactions,
altered rates of drug metabolism, and so forth
Antagonism of the effects of one drug by another
The process of drug interaction with cellular macromolecules (receptors) to alter physiological
function (i.e., receptor theory).
The Steps for Drug Research and Development(R&D)
Preclinical Research:
 1 Pharmaceutical studies
2 Pharmacological studies
General pharmacology
Pharmacodynamics
Pharmacokinetics
Toxicology
Clinical Research:
1 The Organizations for novel drug development
Food and Drug Administration (FDA)
Sino Food Drug Administration (SFDA)
The Center for New Drug Evaluation. GLP, GCP, GMP
2 Clinical Pharmacology:
Phase Ⅰ,Ⅱ, Ⅲ and Ⅳ (Postmarketing Surveillance)
action and the magnitude of effect that is achieved, including the mechanism of action.
2 the source of the drug:
(1) minerals:
Aluminum hydroxide aluminium ------ mucosal protective gastric coating agents
Ferrous ions Fe2 + ------ iron deficiency anemia
Platinum (Pt) -------- anticancer drugs against cancer
Arsenic trioxide arsenic trioxide ----- M3 leukemia
(2) plants: atropine ----- MR blockers
Pilocarpine ----- M-R agonists
* Variety, later learning.
（3）molds: penicillin ----- production process Introduction (students understand):
（4） animals: insulin (porcine, bovine pancreas) ----- hypoglycemic
Heparin (bovine lung, intestine) heparin ----- anticoagulant
（5） the chemical synthesis of synthetic chemistry: Chinese medicine, Western medicine has
been improperly formulation: What is medicine, what medicine?
Medicine Status: abolition debate (student discussion)
（ 6 ） genetic engineering drugs genetic engineering drus: Process Description (students
understand): (multimedia presentation)
（7）Systematic synthetic chemistry: (multimedia presentation)
3pharmacology:
Foundation for development: physiology and chemistry
chemistry
Pure compounds
physiology
Measurement of biological activity
pharmacology
Research contents:
Experimental subjects：
An example of some of the pharmacological effects: anti-arrhythmic drugs, hypoglycemic agents,
analgesics, anti-ulcer drugs, etc.
Drug Mechanism: cellular and molecular level: the role of such channels, receptors, etc.
Pharmacology disciplinary nature: integrated disciplines.
4. drug development：
preclinical testing, clinical testing(4phases)
1、 preclinical testing：
1）Pharmacy: production processes, quality control, stability
2) Pharmacology: Pharmacodynamics and pharmacokinetics (animal)
3) Toxicology: acute toxicity, chronic toxicity, and special toxicity (Introduction)
2、 clinical testing
（1） phase 1：
Who? normal volunteers
Why? safety, biological effects, metabolism
By whom? Clinical pharmacologists
（2） phase 2：
Who? Selected patients by double-blind studies
Why? Therapeutic efficacy, dose range
By whom? Clinical pharmacologists and clinical investigatiors
（3） phase 3：
Who? Large sample of selected patients
Why? Safety and efficacy.
By whom? Clinical investigator
（4） postmarketing surveillance）：
Who? Patients given drug for therapy.
Why? Adverse reaction, patterns of drug utilization, additional indications.
By whom: all physicians.
Example: cisapride (gastrointestinal drugs): Death reported causes (cardiac death, potassium
channel inhibition), measures to restrict or suspend sales.
5、drug nomenclature：
chemical name：
nonproprietary name：
proprietary (trade) name：