Chapter 2 Drugs and the Body

Exam 1

Pharmacodynamics

The study of the interaction between chemical components of living systems and foreign chemicals that enter those systems.

What are the 4 reasons for drug actions?

1. Replace or act as a substitute for missing chemical

2. Increase/stimulate certain cellular activities

3. Decrease/Slow cellular activities

4. Interfere with the function of foreign cells

What are receptor sites?

These are sites that react to certain chemials that causes an effect within the cell.

Pharmocokinetics

This is the study of the absorption, distribution, metabolism,(biotransformation) and excretion of drugs.

What is a loading dose?

This is the 1st does that is higher than the rest of the dose to get the medication to therapeutic level.

How can absorption be effected?

It can be effected based on the route of administration, oral would be the slowest while IV would be the fastest.

Distribution

This is the movement of the drug to the body’s effected tissue by lipid solubility, ionization and perfusion of reactive tissue.

Biotransformation (metabolism)

The liver is the single most important site for metabolism and it changes drug into new, less active chemical.

Excretion

This is the release of the drug from the body and is most often complete by the kidneys.

What is a half-life?

How long it takes for the amount of the drug in the body to decrease to one-half the peak level.

What are some of the factors that can influence drug effects?

Weight, age, gender, physiology factors, pathological factors, genetic factors, immunological factors, psychological factos, environmental factors, accumulation and interactions

In most cases drug are best taken when?

On an empty stomach