Basics

How the drugs moves inside the body

pharmacokinetics

Types of pharmacokinetics

absorption, distribution, metabolism, and excretion of drugs by the body

The effect of the drugs in the body. How it works and what it does

pharmacodynamics

the biochemical and physical effects of drugs and the mechanisms of drug actions

pharmacodynamics

The actual use of drugs in treating patients

pharmacotherapeutics

the use of drugs to prevent and treat diseases.

pharmacotherapeutics

a scientific name that precisely describes the drug’s atomic and molecular structure.

chemical name

an abbreviation of the chemical name.

generic, or nonproprietary

selected by the drug company selling the product.

trade name (also known as the brand name or proprietary name)

The symbol after a trade name indicates that the name is registered by and restricted to the drug manufacturer.

®

Drugs that share similar characteristics are grouped together as a

pharmacologic class (or family)

A second type of drug grouping is the __, which categorizes drugs by therapeutic use

therapeutic class

Traditionally, drugs were derived from natural sources, such as:

• plants

• animals

• minerals

the most active component in plants, react with acids to form a salt that’s able to dissolve more readily in body fluids.

Alkaloids

The names of alkaloids and their salts usually end in

“-ine”

are naturally occurring active components that are found in plants and have both beneficial and toxic effects

Glycosides

Glycosides usually have names that end in

“-in”

give products the ability to attract and hold water. Examples include seaweed extractions and seeds with starch.

Gums

of which the chief source is pine tree sap, commonly act as local irritants or as laxatives and caustic agents.

Resins

thick and sometimes greasy liquids

Oils

Classification of oils

volatile or fixed.

Examples of volatile oils, which readily evaporate, include

peppermint, spearmint, and juniper.

Fixed oils, which aren’t easily evaporated, include

castor oil and olive oil.

The drugs obtained from animal sources include:

hormones

oils and fats (usually fixed)

enzymes

vaccines

provide various inorganic materials not available from plants or animals.

Metallic and nonmetallic minerals

allows direct administration of a drug into the GI system. This route is used when patients can’t ingest the drug orally.

gastric route

In __, drugs are injected into the skin. This form of administration is used mainly for diagnostic purposes, such as testing for allergies or tuberculosis.

intradermal administration

in intradermal administration, needle is inserted at a __ so that it punctures only the skin’s surface.

10- to 15-degree angle

allows drugs to be injected directly into various muscle groups at varying tissue depths

IM route

IM route pro- vides rapid systemic action and allows for absorption of relatively large doses (up to __).

3 mL

allows injection of drugs and other substances directly into the bloodstream through a vein.

IV route

is usually the safest, most convenient, and least expensive route

Oral administration

may be instilled into the rectum or vagina to treat local irritation or infection

Suppositories, ointments, creams, or gels

Drugs that are available as gases can be administered into the respiratory system through

inhalation

In __, small amounts of a drug are injected beneath the dermis and into the subcutaneous tissue

subcutaneous (subcut) administration

What are the area do we use subcu administration

patient’s upper arm, thigh, or abdomen.

Drugs given by the subcut route include nonirritating aqueous solutions and suspensions contained in up to __ of fluid, such as heparin and insulin.

1 mL

used to deliver a drug via the skin or a mucous membrane

topical route

This route is used for most dermatologic, ophthalmic, otic, and nasal preparations.

topical route

Specific types of infusions include:

epidural

intrapleural

intraperitoneal

intraosseous

intra-articular

injected into the rich vascular network of a long bone

intraosseous

injected into a joint.

intra-articular

Who approves and monitor drug

Food and Drug Administration (FDA)

When the Food and Drug Administration (FDA) approves an application for an __, the drug must undergo clinical evaluation involving human subjects.

Investigational New Drug

the drug is tested on healthy volunteers to make sure the drug can be given safely to people.

Phase I

involves trials with human subjects who have the disease for which the drug is thought to be effective.

Phase II

Large numbers of patients in medical research centers receive the drug. This larger sampling provides information about infrequent or rare adverse effects

Phase III

is voluntary and involves postmarket surveillance of the drug’s therapeutic effects. The pharmaceutical company receives reports from doctors and other health care professionals about the therapeutic results and adverse effects of the drug

Phase IV

The term kinetics refers to

movement

covers the progress of a drug from the time it’s administered, through the time it passes to the tissues, until it becomes available for use by the body.

Drug absorption

On a cellular level, drugs are absorbed by several means— primarily through

active or passive transport.

transport that requires no cellular energy

Passive transport

drug moves from an area of higher concentration to one of lower concentration (diffusion).

Passive transport

What concentration does passive transport use

higher concentration to lower concentration

Oral drugs use __ transport;

Passive transport

transport that requires cellular energy

Active transport

the drug from an area of lower concentration to one of higher concentration.

Active transport

What concentration does active transport use

lower concentration to higher concentration

Active transport is used to absorb __, such as sodium and potassium, as well as some drugs, such as _.

electrolytes

levodopa

is a unique form of active transport that occurs when a cell engulfs a drug particle.

Pinocytosis

Pinocytosis is commonly employed to transport the __

fat-soluble vitamins (A, D, E, and K).

drug absorption occurs within seconds or minutes when administered ___

sublingually, IV, or by inhalation.

Absorption occurs at slower rates when drugs are administered by the ___

oral, IM, or subcut routes

At the slowest absorption rates, drugs can take several hours or days to reach peak concentration levels with __

rectally administered or sustained-release drugs.

mechanism where the liver may metabolize much of the drug before it enters circulation

first-pass effect

Drug that releases slowly so it works longer in the body

sustained-release formulas

added to help the main drug work properly, but they do not have therapeutic effect to the body

inactive ingredients

Used to protect the drug or the stomach

coatings

__ are specifically formulated so that they don’t dissolve immediately in the stomach. Rather, they release in the small intestine.

enteric-coated drugs

___, however, are readily absorbed in the stomach and at the beginning of the small intestine.

Liquid forms

is the process by which the drug is delivered to the tissues and fluids of the body

Drug distribution

Distribution of an absorbed drug within the body depends on several factors, including:

• blood flow

• solubility

• protein binding.

The ability of a drug to cross a cell membrane depends on whether the drug is

water or lipid/fat soluble.

drugs that is easily cross through cell membranes,

Lipid-soluble drugs

Lipid-soluble drugs can also cross the __ and enter the _

blood-brain barrier

Brain

Why does Lipid-soluble drugs easily cross through cell membranes?

Because the cell membrane is made of lipid or has fatty (lipid) barrier

As drugs travel through the body, it comes in contact with proteins, such as- __

plasma protein albumin

The portion of a drug that’s bound to a protein is __ and _.

inactive

can’t exert a therapeutic effect

free, or unbound, portion of drugs in protein is

Activated

A drug is said to be __ if more than 80% of it binds to protein.

highly protein-bound

refers to the body’s ability to change a drug from its dosage form to a more water-soluble form that can then be excreted.

Drug metabolism, or biotransformation,

Taken as active form and liver breakdown this as ___ and these have no therapeutic effects

inactive metabolites

Some drugs can be converted to __ meaning they’re capable of exerting their own pharmacologic action.

Active metabolites

can be administered as inactive drugs, called ___, and don’t become active until they’re metabolized.

pro- drugs

refers to the elimination of drugs from the body.

Drug excretion

Most drugs are excreted by the __ and leave the body through _.

kidneys

urine

Drugs can also be excreted through the

lungs, exocrine glands (sweat, salivary, or mammary glands), skin, and intestinal tract.

time it takes for one-half of the drug to be eliminated by the body.

Half-life of drugs

Factors that affect a drug’s half-life include its

rates of absorption, metabolism, and excretion.

In addition to absorption, distribution, metabolism, and excretion, three other factors play important roles in a drug’s pharmacokinetics:

• onset of action

• peak concentration

• duration of action.

refers to the time interval that starts when the drug is administered and ends when the therapeutic effect actually begins

Onset of action

The __ is reached when the absorption rate equals the elimination rate

peak concentration level

The __ is the length of time the drug produces its therapeutic effect.

duration of action

The interaction at the cellular level between a drug and cellular components, such as the complex proteins that make up the cell membrane, enzymes, or target receptors, represents __.

drug action

The response resulting from this drug action is called the

drug effect.

The drug then binds with the receptor to produce its effect.

agonist

The drug’s ability to initiate a response after binding with the receptor is referred to as

intrinsic activity.

If a drug has an affinity for a receptor but displays little or no intrinsic activity, it’s called an

antagonist

Antagonists can be

competitive or noncompetitive

competes with the agonist for receptor sites. Because this type of drug binds reversibly to the receptor site, administering large doses of an agonist can overcome the antagonist’s effects.

competitive antagonist