L10 Terms (149 + Study Tables)

pharmacology

The study of drugs and their actions and effects on the body

drug

Any substance that can alter the way the body can function

5 Branches of Pharmacology

(1) Pharmacokinetics

(2) Pharmacodynamics

(3) Pharmacotherapeutics

(4) Pharmacognosy

(5) Toxicology

Pharmacokinetics

The study of what the body does with the drug after administration; the study of the body's absorption, distribution, metabolism, and elimination (ADME) processes and their effects on the drug

Pharmacodynamics

The study of biochemical and physical effects of drugs and how they work

Pharmacotherapeutics

The study of the use of drugs to prevent and treat diseases

Pharmacognosy

The study of natural resources of drugs (plants, animals, and so on)

Toxicology

The study of poisons and drug toxicity

4 Stages of New Drug Development

(1) Stage I: Preclinical Stage

(2) Stage II: Clinical Investigation Stage

(3) Stage III: Investigational New Drug Review

(4) Stage IV: Post-Marketing Surveillance

Stage I

Preclinical Stage

In this step, safety and effectiveness are evaluated using the pharmacology and toxicology data obtained from animal research conducted and it is determined if that data can be applied to humans. The candidate drug is tested on a small number of healthy volunteers, primarily to evaluate safety. If the data at this level support the candidate drug moving forward, an investigational new drug application (IND) is submitted to the FDA. Once the FDA accepts the application, the next stage begins.

Stage II

Clinical Investigation Stage

Human testing continues in this stage. There are three different phases of testing, called clinical phase trials. This is the longest part of the new drug process. It can take anywhere from 2 to 10 years, but on average it is around 5 years. New agents are tested on healthy volunteers to determine efficacy and side effects. Once these studies are completed, the IND is sent back to the FDA for the next level of approval.

Stage III

Investigational New Drug Review

Involves further review of the IND by the FDA. While this is occurring, the company may continue with trials and testing. In this stage, testing is performed on a large group of individuals with the disease or condition the medication is trying to receive approval for a safe therapeutic range. If the IND is approved, the company may then proceed to the final stage of drug development. If it isn't approved, trials stop and the company addresses concerns before further development can occur. This stage can take anywhere from months to years.

Stage IV

Post-Marketing Surveillance

Testing continues even after the drug is fully approved for patient use. This Phase testing is important for a few reasons. First, some adverse effects may take longer to appear than the period of time observed in Phase III trials. Second, some adverse effects may be uncommon enough that they will not be seen in Phase III trials but may emerge after thousands or millions of patients receive the drug. By monitoring the drug as more and more patients are exposed to it, companies can further document its safety and effectiveness.

Class I Drug Recall

Product is dangerous or defective and can potentially cause serious injury or death

Class II Drug Recall

Product could potentially cause adverse effects or temporary illness or injury

Class III Drug Recall

Product is unlikely to cause adverse health effects; however, it violates FDA labeling or manufacturing laws

biopharmaceutics

The relationship between the physicochemical properties of the drug, including the bioavailability of the drug, and how it produces a desired therapeutic effecy

bioavailablity

The rate and extent that the active ingredient of the drug is available at the site of action

receptor site

The site of action that determines the effect, or undesired effect, of a drug. Once drugs are circulating in the bloodstream, they locate this site on which to attach. This may "turn something on," "turn something off," or prevent some other chemical from reacting.

selective receptors

Receptors that allow only one key to enter the lock

antagonist

Prevents a cell from functioning or prevents another substance from binding. The receptor is "blocked" from activity

agonist

Activates a receptor site. It may turn something on, speed it up, or slow it down

minimum effective concentration (MEC)

The minimum concentration of the drug that will produce the therapeutic effect

minimum toxic concentration (MTC)

The minimum concentration of the drug that will produce a toxic effect

therapeutic window

"Sweet Spot"; the goal is to keep the concentration between the MEC and the MTC

narrow therapeutic index (NTI) medication

For some medications, the range between a therapeutic dose and a toxic dose is very small. Blood levels and other labs should be monitored very closely to ensure the patient is on the correct dose. If the dose is too high, the drug can accumulate in the patient's bloodstream and lead to serious side effects.

NTI Medications (6)

(1) Digoxin

(2) Levothyroxine

(3) Lithium

(4) Phenytoin

(5) Theophylline

(6) Warfarin

half-life of a drug

The time it takes for the drug concentration to be reduced by one-half (50%)

Absorption

The process where the drug enters into the body and into the bloodstream. It depends on the route of administration, its solubility, and other factors like the presence of food or acid (as in the stomach). The drug formulation plays a big role in the drug's solubility rate. For example, a liquid formulation of a drug is already dissolved, whereas a solid tablet or capsule form requires further dissolution. Most drugs are administered via the oral route; however, medications can enter through a variety of routes, including intravenously, intramuscularly, subcutaneously, rectally, and topically. Without this, the other steps within the process cannot occur.

Distribution

The process of the medication moving through the bloodstream and tissues to both the site of action and to other areas in the body. Is dependent on physiological properties of the body and the drug itself, like the size of the drug molecule, its affinity for receptors, and its stability in the bloodstream

Metabolism

"Biotransformation"; The process of converting the drug into other compounds in preparation for elimination from the body. Is affected by organ function (commonly the liver). If the liver is damaged or unhealthy in any way, it can affect drug concentrations because this process may not occur or may be slowed.

Elimination

The process by which the drug is removed from the body. The kidneys (through urination) are the primary routes of this process. Drugs can also be removed through the liver (feces/defecation), through perspiration, and saliva.

pharmacokinetic modeling

Predicts the way ADME occurs for certain drugs

zero-order elimination process

When a fixed quantity is processed per unit of time. Examples are body processing alcohol, phenytoin, and aspirin

first-order elimination process

When a constant fraction of the drug is eliminated per unit of time. The rate of drug elimination is proportionate to the amount of drug that is currently in the body.

3 Names for Each Drug

(1) Chemical Name

(2) Trade Name

(3) Generic Name

Chemical name

This name is the one that, generally, only basic scientists use. It helps them classify the drug by its chemical makeup. Plant, animal, and synthetic drugs can all be classified in this manner.

Trade name

"Brand Name"; Created by the manufacturer. It is properly registered, is the legal property of the company, and is protected by copyright laws. These laws also protect the product from duplication for a set amount of time, preventing others from manufacturing and competing with the company.

Generic name

This is the drug's nonproprietary name. Is the official name of the drug. It's far simpler than the chemical name but not as easily pronounced as its trade name. They are manufactured once a copyright has expired on a trade-name drug. The active ingredient is chemically identical to the originally produced, branded product. The only difference is that the patent protection afforded to the original manufacturer has expired and multiple manufacturers are now allowed to produce the drug. They are regulated by the FDA in the same manner. They are generally less expensive than the trade-name drugs. Pharmacies organize their shelves by these names and prefer that physicians write prescriptions this way, so they can dispense the this version or whatever brand name they happen to stock. Most states have laws stating that, if available, they must dispense the lowest-cost generic formulation stocked. Patients and prescribers can override this requirement if desired.

5 Sources of Drugs

(1) Plant

(2) Animal

(3) Mineral

(4) Synthetic

(5) Engineered

Plant Sources

Sorted by chemical and physical properties; Organic compounds combined with an acid, called a salt

Examples of Plant Sources (4)

(1) Tobacco = nicotine

(2) Poppy seed = opium (morphine sulfate)

(3) Foxglove = digitalis (digoxin)

(4) Willow bark = salicylic acid (aspirin)

Animal Sources

Body fluids and glands, used to create drugs; Enzymes and hormones, common drugs from animals

Examples of Animal Sources (2)

(1) Enzymes = pancreatin, pepsin

(2) Hormones = thyroid, insulin

Mineral Sources

Taken from the earth and soil; Unavailable from plant or animal sources

Examples of Metal Sources (2)

(1) Metals = iron, silver, gold

(2) Electrolytes = potassium, calcium, sodium

Synthetic Sources

Drugs created from chemistry; Not found naturally in plant, animal, or mineral sources

Examples of Synthetic Sources (2)

(1) Synthetics = meperidine, sulfonamides, oral contraceptives

(2) Semi-synthetics (altering of a natural compound)—penicillin, propylthiouracil

Engineered Sources

Drugs created by gene splicing or genetic engineering; Replacement of missing or nonfunctional genes

Examples of Engineered Sources (4)

(1) Newer forms of insulin

(2) TPA (tissue plasminogen activator), used in breaking down blood clots

(3) Growth hormones

(4) Cancer drugs

2 Factors That Affect Drug Therapy

Gender and Age

3 Types of Dosage Forms

(1) Solid Drugs

(2) Semisolid Drugs

(3) Liquid Drugs

Solid Drugs

This dosage form is intended primarily for oral use.

Tablet

Compressed powdered form of a drug

Types of Tablets (5)

(1) Chewable

(2) Sublingual

(3) Buccal

(4) Enteric-Coated

(5) Buffered

Chewable Tablets

Flavored, sugar-based; EX. Antacids, anti-flatulents

Sublingual Tablets

Dissolved under the tongue and rapid absorption; EX. Nitroglycerin (used for angina)

Buccal Tablets

Placed between cheek and gum and is slower than sublingual; EX. Anti-nausea drugs, nicotine replacement drugs

Enteric-Coated Tablets

Protective coating prevents dissolving in stomach and dissolves in the intestinal tract; EX. Erythromycin (macrolide antibiotic), potassium tablets

Buffered Tablets

Contains an antacid and reduces stomach irritation; EX. Aspirins (Bufferin®, Excedrin®)

Pill

This is a single-dose unit of medicine made by mixing the powdered drug with a liquid and rolled into a round or oval shape.

Plaster

Plaster is a combination of a liquid and powder that hardens when dried. These are applied in the semisolid state, allowed to dry, and removed at a later time. An example would be a salicylic acid plaster applied to corns.

Capsule or Caplet

Capsules contain the drug within a hard gelatin casing. Physicians prescribe these when the drug has an unpleasant odor or taste. A caplet is shaped like a capsule but has the hard form of a tablet.

Gelcap

Gelcaps contain an oil-based medication inside a soft, gelatin capsule. They're easy to swallow and release their contents quickly.

Powder

A powder is a drug that is dried and ground finely. Powders can be administered topically, orally, or dissolved and injected.

Troche or Lozenge

This is a hard dosage form intended for local application in the mouth or throat. It's meant to dissolve slowly and administer the drug over time. Cough suppressants and sore throat medication are examples.

Semisolid Drugs

Used for topical application. They are soft and pliable.

Suppository

This is a bullet-shaped drug inserted rectally or vaginally for absorption through the mucous membranes

Ointment

A semisolid, oil-based medication. It's used topically by rubbing it on the affected area.

Cream

Water-based, semisolid medications. They're used similarly to ointments.

Gel

A jelly-like substance that contains medication for topical use. Many are alcohol-based. They're non-greasy and absorb quickly when applied.

Liquid Drugs

Can be used orally, topically, or as an injection

Syrup

High concentration of sugar; Absorbed quickly

Solution

Dissolved in water or saline; Absorbed quickly

Elixir

Contains water, alcohol, and sugar; Caution for diabetics or alcoholics

Tincture

Alcohol-based; Primarily used topically

Liniment

Drug mixed with oil, soap, water, and/or alcohol; External use only

Emulsion

Combination of two products that aren't compatible; Oil in water; water in oil

Suspension

Mixed with a liquid, but not dissolved; Drug "suspended" in the liquid

3 Routes of Administration

(1) Oral Route

(2) Topical Route

(3) Parenteral (Injectable) Route

Oral Routes

These are the most common and cost effective. They absorb more slowly but are easier for patients to take, therefore increasing the compliance factor. Taken by mouth. They can be in tablet or liquid form. Tablets are swallowed with water or dissolved in the mouth. Liquids can be administered in several ways.

Topical Routes

Used for a variety of disease states. Pain management, hormone therapy, and dermatological diseases can all be treated. Apply externally to the skin or mucous membranes of the body. These include the eyes, ears, nose, lungs, skin, and rectal or vaginal cavities.

Parenteral (Injectable) Routes

These are quicker acting and are primarily seen in the hospital setting. These medications are used when immediate results are necessary or when a patient can't take the medication orally. Given by injection of some form.

Medicine Cup

Usually 1-oz size; Dose markings on cup in metric (mL) and apothecary (tsp/tbsp) measures

Oral Syringe

Designed for oral use only (no way to attach a needle); Calibrated with dosage markings in metric and apothecary

Medicine Dropper

Calibrated in drops or mL markings

Transdermal

Drug embedded in a patch; Applied to skin

Inhalation

Drug inhaled in vapor or gas, or powder form; EX. Inhalers, nebulizers

Opthalmic

Instilled into the eye; EX. Ointment or solutions

Otic

Instilled into the ear; EX. Solution or suspensions

Nasal

Inhaled or liquid drops

Rectal or Vaginal

Suppository form; Inserted into cavity; Vaginal = creams or foams

Intradermal

Injected just under the skin (epidermis layer); Extremely small needle: 27-28G

Subcutaneous (SQ)

Injected into the subcutaneous tissue, also called the adipose tissue; Very small needle: 25-26G

Intramuscular (IM)

Injected deep into muscle tissue; Needle size varies: 16G-21G

Intravenous (IV)

Injected into a vein; Moderate needle: 18-21G

beneficial effects

Occur when the drug performs the action for which it is being used

Therapeutic effect

The desired outcome of the drug treatment that was prescribed.

Local effect

An effect that occurs on a specific part of the body.

Systemic effect

An effect that occurs throughout the entire body.