Pharm Unit 2 - Smith

• Plant - Digoxin, taxol, caffeine, nicotine
• Animal - Hormones
• Mineral - Calcium
• Lab synthesis (genetic engineering) - Procrit, insulin

• Based on therapeutic use
• Broadly what the drug does
• Examples - antimicrobials kill bugs, antihypertensives lower BP

Based on the mechanism of action - how the drug works or exerts its activity

• Chemical - Very long, complicated
• Generic - Usually describes the active ingredient
• Brand/Trade - Assigned by pharmaceutical company marketing the drug

What the body does to the drug

• Absorption
• Distribution
• Metabolism
• Excretion

• How fast a drug leaves the site of administration
• Oral, topical, IV

After a drug goes through the process of absorption, the bioavailability is the amount of the drug left available for the body to use

Movement of drug to site of action

Drug is altered/transformed

• Primary site for drug metabolism
• Liver

• Elimination from body
• Renal - primary site

How fast drug excretiates

How long a drug takes to start working

Drug level at its maximum

How long drug lasts

How long it takes for drug concentration to decrease to 1/2

Larger initial dose needed to get drug concentration up

Amount of drug needed to maintain level of concentration

Amount of drug in body needed to get therapeutic effect

What drug does to body

How much drug needed for therapeudic response

• How strong drug is
• Strong drug --> need less for effect

How well drug works

Drug (key) attaches to cell receptor and opens up cell

Produces response just as body would naturally

Not as good as an agonist but produces a similar response

• Opposite response of agonist
• Lock on and block cell receptor

Produces unexplained or unexpected response

Therapies you can do with drugs

Something that comes on abruptly

Make an educated guess and start treatment before it is ordered

Chronic, ongoing

Provide comfort but not a cure

Preventative (vaccine)

Response you wanted for patient

Tolerable effects of drug 

• Extended side effect
• Usually intolerable

Hypersensitivity response of the immune system

• Two drugs with similar actions to achieve one goal
• Narcotic and tylenol - both used for pain

• Two drugs, different pathways, same result
• Hypertensive and diuretic

Lethal effects when combined in body

• Response we have caused
• Risk vs. benefit
• The drug may cause damage to body but is needed for the survival of patient

Causes fetal defects

Cancer causing agents

IV nutrition

Pregnant, breast feeding

Patient has multiple diseases

Weight based

• Multiple drugs --> varying drug levels and interactions
• Requires close monitoring