Drug – chemical introduced into the body to cause some changes
• WHO def: any product/subs used to modify/explore physiologic system/pathologic states for the benefit of the patient
Pharmacology – study of the manner in which the function of living system is
affected by chemical agents/drugs
• Science concerned with history, sources, physical & chemical properties of drugs & the way in which drug affects living system

Subdivisions of pharmacology:

1. pharmacodynamics – study of the biochemical & physiological effects of drugs & mechanisms of action
• what the drug does to the body
2. pharmacokinetics – deals with the absorption, distribution, biotransformation & excretion of drugs
• what the body does to the drug
3. pharmacotherapeutics – study of drugs used in the diagnosis, prevention, suppression, & treatment of diseases
• deals with beneficial effects of the drugs (medicines)
4. pharmacognosy – study of drugs in their original unaltered state; origin of drugs
• source of drugs
• ex: penicillin from penicillium (fungi)
5. Toxicology – study of biologic toxins: study of poison & its effects deals with deleterious effects of physical & chemical agents (including drugs) in human

Pharmacoeconomics – study of relationship of drugs & economics

Pharmacovigilance – science of collecting,researching, analyzing, & evaluating set of information about adverse drug effects.
Receptor – a component of the cell that interacts with drug, initiating a chain of biochemical events leading to drugs’ observed effects
• Human body works through complicated series of chemical reactions & processes
• Important aspects of nursing: understanding how drug ant on body to cause changes & apply that knowledge in clinical setting
Patients take complicated drug regimen & receive potentially toxic drug
Some manage their own care at home
• Nursing responsibilities regarding drug therapy:
Administering drugs
Assessing drug effects
Intervening to make drug regimen more tolerable
Provide patient teachings about drugs & drug regimen
• Knowing how drug works --- easier to handle --- enhances drug therapy