GENERAL AND SYSTEMIC PHARMACOLOGY (PHRM-205)
Lecture No. 1
INTRODUCTION TO PHARMACOLOGY
Pharmacology is the science that embraces the knowledge of the history, source, physical and
chemical properties, compounding, biochemical and physiological effects, mechanism of
action, absorption, distribution, biotransformation and excretion of drugs. It is also defined as
an experimental science dealing with the properties of drugs and their effects on living system.
Pharmacodynamics is the study of the biochemical and physiological effects of drugs and
their mechanism of action. It is the response of the organism to the action of a drug in the
absence of a disease. Pharmacodynamics is 'what the drug does to the body'.
Pharmacokinetics is the study of the actions of the drugs in the body over a defined period of
time. It deals with the absorption, distribution, biotransformation and excretion of the drug.
Pharmacokinetics is 'what the body does to the drug'.
Pharmacometrics is the study of the techniques used in the measurement of drug effects to the
administered dose of drug.
Pharmacogenetics is the study of genetically determined variations in animals that are
revealed by the effect of drugs.
Pharmacogenomics This term describes the use of genetic information to guide the choice of
drug therapy on an individual basis. .
Pharmacoepidemiology is the study of drug effects at the population level. It is concerned with
the variability of drug effects between individuals in a population and between populations.
Pharmacoeconomics aims to quantify in economic terms the cost and benefit of drugs used
therapeutically.
Pharmacy is the science that deals with the preparation, formulation, manufacture,
standardization, preservation and dispensing of drugs. The term pharmacy also indicates the
place where drugs are dispensed or sold.
Pharmacognosy is the study of the source of drugs. It also deals with the physical and chemical
properties of drugs.
Materia medica is an obsolete didactic subject that was concerned with pharmacy, posology,
pharmacognosy and indications for therapeutic use of the drug.
Metrology is the study of weights and measures as applied to the preparation and
administration of drugs.
Chronopharmacology is the study of how the effects of drugs vary with biological timing and
endogenous periodicities.
Pharmacovigilance is the science and activities relating to the detection, assessment,
understanding and prevention of adverse effects or any other drug-related problem.
Pharmacoepidemiology is the study of the use of and the effects of drugs in large numbers of
people.
Branches of Pharmacology
Neuropharmacology is the study of neurophysiological or neurobiochemical functions of the
nervous system including the brain, spinal cord, and the nerves that are modified by drug
action.
Cardiovascular pharmacology concerns the effects of drugs on the heart, the vascular
system, and those parts of the nervous and endocrine systems that participate in regulating
cardiovascular function.
Molecular pharmacology deals with the biochemical and biophysical characteristics of
interactions between drug molecules and those of the cell. It is molecular biology applied to
pharmacology and toxicology.
Biochemical pharmacology is the study of action of drugs and drug metabolism, how drugs
interact with, and influences, the physiology of the organism.
Behavioral pharmacology studies the effects of drugs on behavior of organism. It includes
topics such as the effects of psychoactive drugs on the phenomena of learning, memory,
wakefulness, sleep and the behavioral consequences of experimental intervention in enzyme
activity and brain neurotransmitter levels and metabolism.
Endocrine pharmacology is the study of drugs that are either hormones or hormone
derivatives, or drugs that may modify the sections of normally secreted hormones.
Clinical pharmacology is the application of pharmacodynamics and pharmacokinetics to
patients with diseases, it also includes pharmacogenetic component. Clinical pharmacologists
study how drugs work, how they interact with the genome and with other drugs, how their
effects can alter the disease process, and how disease can alter their effects. Clinical trial
design, the prevention of medication errors, and the optimization of rational prescribing are
critical components of clinical pharmacology.
Chemotherapy is the area of pharmacology that deals with drugs used for the treatment of
microbial infections and malignancies. Chemotherapeutic agents selectively inhibit the growth
of, or kill, the infectious agent or cancer cell without seriously impairing the normal functions
of the host.
Toxicology is the science of adverse effects of chemicals/ drugs on living systems. It also
includes problems of drug safety, effects of drug over dosage.
