Dr. Steven I. Dworkin Pharmacology for the Health Sciences Lecture 3

Dr. Steven I. Dworkin

Pharmacology for the Health Sciences

Lecture 3


How are Drugs Named?• Chemical Name

– Specifies chemical structure• Pre patent or release name

– Typically drug company letters and numbers• Generic Name

– Nonproprietary name (each drug has only one generic name)

• Brand or Trade Name– Market name for a particular company

• Common or Street Name– Users name


What’s in a Name

Chemical Name Generic Name Trade Name

N-(4-hydroxyphenyl) acetamide Acetaminophen Tylenol

7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one

Diazepam Valium

4-[4-(p-chlorophenyl)-4-hydroxypiperidino]-4'-fluorobutyrophenone

Haloperidol Haldol

5-thia-1-azabicyclo [4.2.0]-oct-2-ene-2 carboxylic acid, 7-[(aminophenylacetyl)amino]-3-methyl-8-oxo-, monohydrate

Cephalexin Keflex, Keforal, Keftabs

DL-threo-2-(methylamino)-1-phenylpropan-1-ol

Pseudoephedrine Sudafed

N''-cyano-N-methyl-N'-[2-[[(5-methyl-1H-imidazol-4-yl) methyl]thio]ethyl]guanidine

Cimetidine Tagamet


Rose

Chemical Name isobutylphenyl propionic acid

In-house name

Generic Name ibuprofen

Brand Names Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, Pediacare Fever etc

Street Non-asprin headache reliever

ibuprofen (ī'byūprō'fən) , nonsteroidal anti-inflammatory drug (NSAID) that reduces pain, fever, and inflammation. Along with naproxen and ketoprofen, ibuprofen belongs to the propionic acid class of NSAIDs. It was first made available in 1967. Like other NSAIDs, it acts by inhibiting the body's production of prostaglandins. Available over the counter in a variety of preparations (e.g., Advil, Motrin, Nuprin), it is commonly used to treat rheumatoid arthritis, gout, and painful menstruation. Side effects include rash, alteration of platelet function and bleeding, and intestinal upset, which can lead to gastritis. Like other NSAIDS, it appears to have no potential for abuse or physical dependence. It should not be used by those who are allergic to aspirin.

http://www.answers.com/main/ntquery?method=4&dsid=2040&dekey=naprox&gwp=11&curtab=2040_1

http://www.answers.com/main/ntquery?method=4&dsid=2040&dekey=ketopro&gwp=11&curtab=2040_1

http://www.answers.com/main/ntquery?method=4&dsid=2040&dekey=prostagl&gwp=11&curtab=2040_1


Drug Resources

http://www.merck.com/


Classification of Drugs

• Grouping by chemical structure.

Specific Examples

Core Structure Generic Name Trade Name

Tetracyclines Doxycycline Vibramycine

Corticosteroids Prednisone Meticorten

Benzodiazepines Diazepam Valium


Classification of Drugs

• Mechanism of action

– Serotonin uptake inhibitors

• antidepressants

– beta blockers

• Anti-hypertensives

– H2 blockers

• Anti-histamines


Drug Classification

• Therapeutic Categories and Subcategories

Therapeutic Category Examples of Subcategories

Analygesics NSAIDs

Opioids

Antibiotics Tetracyclines

Penicillins

Cephalosporins

Antihypertensive –Blockers

Diuretics

ACE Inhibitors

Anti-inflammatory drugs NSAIDs

Corticosteroids

Asthma Drugs –Blockers

Corticosteroids

Leukotriene modifiers


Drug Classification

Classification Characteristics

OTC drugs Drugs that do not require a prescription. May contain a lower dose of a prescribed compound,

Prescription drugs Greater potential for adverse effects. Untoward drug interactions may occur. Use is monitored by a physician.

Controlled Substances Schedules drugs evaluated for abuse liability. More restrictive requirements regarding distribution, storage, and record keeping


The Feds

Year Act Purpose Comment

1906 Federal Pure food act

Prohibit adulteration and misbranding of medications

USP standards established for ingredients. Drug did not have to be safe or effective

1938 Drug and Cosmetic Act

Required safety of new drug approval by FDA

Start of NDA process

1952 Durham-Humphrey Amendment

Differentiated prescription and nonprescription

Drugs unsafe without medical supervision required prescription, refill restriction

1962 Kefauver-Harris Amendment

Required effectiveness of prescription and nonprescription approval by FDA

Drugs developed between 1938-1962 included

1970 Comprehensive Drug Abuse Act

Established Categories for drugs with abuse potential.

DEA to enforce the act





Pre Clinical Trials• In vitro studies• In vivo studies

– Use of standard animal models• Efficacy• Potency• Safety• LD determination• ED determinations

– Therapeutic Ratio• Abuse Potential or Liability

– Drug self-administration


Clinical Trials

• Introduction– Before a pharmaceutical company can initiate testing in humans, it must

conduct extensive preclinical or laboratory research. • Preclinical research typically involves years of experiments in animal

and human cells. The compounds are also extensively tested in animals.

• 100-300k compounds screens 100-300 compounds 1 or 2 lead compounds

• Pharmaceutical company provides selected data to the Food and Drug Administration (FDA) with a requesting approval to begin testing the drug in humans.

• This is called an Investigational New Drug application (IND).• Typically this is when the clock starts clicking and the PC has the

next 11 years of exclusive patent rights.


Phase Purpose Subjects Duration Outcome

Phase I how drug absorbed, metabolized, and excreted and side effects over range of doses

healthy volunteers (20 to 100), who are usually paid for participating in the study.

several months 70 percent of experimental drugs pass this initial phase of testing

Phase II determine relative safety of the new drug, and its effectiveness.

.

several hundred patients randomized trials, drug vs control often blinded.

several months to two years 33 percent of experimental drugs successfully complete both phase I and phase II studies

Phase III provide drug company and the FDA with a more thorough understanding of the drug's effectiveness, benefits, and the range of possible adverse reactions.

several hundred to several thousand patients., most phase III studies are randomized and blinded trials.

several years Seventy to 90 percent of drugs that enter phase III studies successfully complete this phase of testing FDA approval for market

ing the drug.

Phase IV objectives: (1) studies often compare a drug with other drugs already in the market; (2) studies are often designed to monitor a drug's long-term effectiveness and impact on a patient's quality of life; and (3) many studies are designed to determine the cost-effectiveness of a drug therapy relative to other traditional and new therapies.


Issues

• The New Drug War (non-US markets)• Involvement of Pharmaceutical Companies• Involvement of Interest Groups• Role of advisory panel• Role of FDA officials• Publication and disclosure of negative findings• When things go wrong?

– Cox-2 inhibitors• Media

– Steroids– Alternative Medications


Questions

• Why are drugs categorized?• What are the major differences between name brand and generics

drugs?• Approximately how many drugs are tested for every drug that is

approved ?• What federal agency is responsible for determining the safety and

efficacy of new pharmaceuticals?• What federal agency is responsible for enforcing the regulations for

scheduled compounds• What are the basic differences between OTC and prescription drugs?• Under what conditions can a schedule I drug be prescribed for a

patient.• Name 2 Schedule II and 3 Schedule III compounds, what is one major

difference between these compounds (difference of Schedule II compared to Schedule III) ?

• Who is responsible for the appropriate use of a compound?

Documents

Dr. Steven I. Dworkin Pharmacology for the Health Sciences Lecture 3