Pharma-Kirley-gy

Pharmacology

The study of drug action; analysis of the interactions between a living organism and chemicals that affect function. (concerned with research)

Pharmacodynamics

what the drug does to the body

Pharmacokinetics

what the body does to the drug

Drug Origins (4 types)

natural drug source, crude drug preparation, pure drug extract, pharmaceutical formulation.

Drug Nomenclature

chemical name, trivial name, generic name, trade name

US Food and Drug Administration’s (FDA) Mission

protecting and advancing public health by assuring the safety, efficacy, and security of products, speeding up innovation, and properly informing the public.

CDER

Center for Drug Evaluation and Research

CBER

Center for Biologics Evaluation and Research

Drug Clinical Trial Phases

3 Phases:

• Phase I = 20-100 patients, safety testing

• Phase II = Several hundred patients, testing for some short term safety but mainly testing for effectiveness

• Phase III = Several hundred to several thousand, tests safety, dosage, and effectiveness

MedWatch

FDA Safety Information and Adverse Reporting Program, allows for healthcare workers and consumers to report issues they’re having with medications.

Benefits versus Risks in Drug Therapy

FDA evaluates benefits/risks for population, providers evaluate benefits/risks for patients, and patient judges personal values.

(Black) Box Warning

Strongest physician and patient advice, issued by FDA, indicate that the drug has life threatening effects

Dietary Supplement Health and Education Act (DSHEA)

define dietary supplements and dietary ingredients, establish a “new framework” for assuring safety, outline “guidelines” for literature displayed where
supplements are sold, provide for use of claims and nutritional support
statements, require ingredient and nutrition labeling, grant FDA the authority to establish good manufacturing practice (GMP) regulations.

Nicotine

Agonist

Tubocurarine

Antagonist

Agonist

Activates the receptor so as to produce the response. Active by itself.

Antagonist

Blocks the action of agonist. Has no activity in absence of agonist.

Two Traits of Receptors

Saturable, stereospecific

Potency

EC50, is a concentration, read from x-axis, INDEPENDENT of efficacy; higher potency can mean greater selectivity, fewer side effects.

Efficacy

Emax, is a response, read from y-axis; INDEPENDENT of potency; more important than potency in therapeutics.

Spare Receptors

EC50 < Kd; cause greater sensitivity to drugs and agonist

Drug Specificity

Very unusual, drugs bind to only one type/subtype of receptor or target

Drug Selectivity

Common, drugs bind to multiple types/subtypes of receptors or targets (often with varying affinities)

-Drug Non-Specificity

Is a source of many drug side effects and for multiple effects of a single drug

Diffusion through lipids, diffusion through aqueous channels, carriers

Routes by which solutes and other drugs can traverse cell membranes

Blood Brain Barrier

Prevents transcapillary movement through “fenestrations,”

6 Routes of Administration

1. oral/rectal

2. intravenous

3. percutaneous

4. intramuscular

5. inhalation

6. intrathecal

4 Routes of Elimination

7. Urine

8. Expired Air

9. Milk, Sweat

10. Feces

First Pass Effect

Also known as “presystemic,” is clearance of an oral dose of drug; significant fraction of some oral drugs is cleared by liver before reaching systemic circulation.

Two Phases of Drug Metabolism

Phase I: oxidation, hydrolyzation, dealkylation, deamination

Phase II: Conjugation

Importance of Pharmacokinetics

There are a significant number of drugs, often those with low
therapeutic indices, whose proper doses vary from patient to patient
and must be calculated for individual patients; miscalculation is a major cause of latrogenic illness and a major issue in medical malpractice.

Plasma Drug Concentration

Cmax = max plasma concentration, MEC = Minimal Effective Concentration, AUC = Area Under the Curve, Tmax = time to max plasma concentration, Bioavailability = fractional amount of unchanged drug which is administered (by a route different than IV) that ends up in plasma (blood) compared to the total amount of drug
which is administered

Bioequivalence of Drugs

The time to peak, peak concentration, and AUC must all be equal for this

Vd

Apparent volume of distribution of a drug, usually exceeds actual plasma volume, determined by experiment; Vd = dose given / [drug in plasma]

First Order Drug Elimination Kinetics

A constant fraction of drug is removed per unit time

Zero Order Drug Elimination Kinetics

A constant amount of drug is removed per unit time

Alcohol Elimination

Zero Order

Drug Half-Life

The time needed to go halfway from the starting drug concentration to the
new steady state plasma drug concentration