Medicine and DrugsIB Chemistry IIIRobinson High SchoolAndrea Carver

Introduction• Natural chemicals have been used for healing

properties for thousands of years.• In the 20th century, molecules are synthesized

specifically to treat illnesses.▫Treatment for smallpox, malaria, tuberculosis,

polio• Problems such as abuse, excesses, and

antibiotic resistance have arisen.• New diseases necessitate proactive drug

development and distribution.▫Avian flu, Ebola, AIDS pandemic

Pharmaceutical Products: IB Objectives•D.1.1 List the effects of medicines and

drugs on the functioning of the body.•D.1.2 Outline the stages involved in

research, development, and testing of new pharmaceutical products.

•D.1.3 Describe the different methods of administering drugs.

•D.1.4 Discuss the terms therapeutic window, tolerance, and side-effects.

The Human Body’s Defense System•The body responds to many types of defect

and breakdown naturally. It is self-healing.•The body must also must address the constant

attacks of microorganisms (invaders).•The immune system consists of complex

systems of defensive and healing processes (lines of defense).

•Symptoms of illness are often immune system responses to invading organisms.▫Examples: runny nose, fever

Defense MechanismsFirst Defense: Barriers to Entry

Second Defense: Innate Immune System

Third Defense: Adaptive Immune System

•Skin

•Mucous membranes

•Closures and secretions of natural openings (lips, eyelids, ear wax, etc.)

•WBC’s engulf invaders (phagocytosis)

•Blood clotting prevents blood loss and further invasion

•Inflammatory response

•WBC’s produce antibodies to recognize and destroy the invaders

•Memory cells enable body to quickly respond to repeat invasion by same organism

Non-specific mechanism

Non-specific mechanism

Specific mechanism

The Immune System + Medicine•Medicine should be used to supplement

the natural self-healing processes of the body.

•Goal should be to maximize the effectiveness of the body’s natural defense mechanisms.

•When is medicine necessary?•In what cases might medicine be more

detrimental than beneficial?

“Drug” versus “Medicine”

•Drug▫Chemical that affects how body works.▫May have positive or negative effects.▫Associated with illegal substances.

•Medicine▫Substance that improves health. ▫May be natural or synthetic.▫Synthetic medicines may include active and

inactive ingredients.

Drug Affects on the Body

•Alteration of physiological state such as consciousness, activity level, coordination.

•Alteration of incoming sensory sensations.•Alteration of mood or emotions.

Basic Classification of Drugs

•Analgesics, stimulants, depressants, and mind-altering drugs affect the nervous system and brain.

•Antacids target metabolic processes.•Antibacterials and antivirals help the

body fight infection by microorganisms.

The Placebo Effect

•The placebo effect occurs when patients gain therapeutic benefits from their belief that they are taking a useful drug, even though the drug they have been given is inert.

•Mechanism is unclear.•May be related to the brains release of

natural healing or pain relieving chemicals.

•Typically experienced by 1/3 of control group.

Routes of Drug Administration

• Best method of delivery is determined considering chemical nature of drug, patient condition, and target organ.

Administration Method

Description Example

Oral Taken by mouth Tablets, capsules, pills

Inhalation Vapor inhaled; smoking Asthma medications; cocaine, nicotine

Skin Patches Absorbed directly through skin into blood

Some hormones (estrogen), nicotine

Suppositories Inserted into rectum Drugs for digestive symptoms, hemorroids

Eye/ear drops Liquids directly dropped in

Antibiotics for ear/eye

Parenteral- by injection •Intramuscular•Intravenous•Subcutaneous

•Many vaccines•Local anesthetics•Dental injections

Methods of Administration

Physiological Effects of Drugs

•Drugs usually have more than one effect:▫Therapeutic Effect

Intended physiological effect Beneficial

▫Side Effects Unintended physiological effects May be beneficial or adverse Patients should be monitored and made

aware of all possible side effects of a prescribed drug

Dosing•Dosing regime- amount of drug per dose and

frequency of doses administered.▫Goal is to achieve and maintain a constant

therapeutic concentration of drug in the blood.•Therapeutic window- the range in

concentration between the therapeutic level and toxic level of drug in the blood.▫Must be above therapeutic level to see benefits.▫Must be below toxic level to avoid damaging

effects or death.

Therapeutic Window

Effects of Extended Drug Use/Abuse

• Tolerance- reduced response to a drug following prolonged use.▫Higher dose required for same response which

increases chance of adverse side effects.▫May be due metabolic or receptor changes.

• Dependence/Addiction- occurs when individual needs drug to feel normal.

• Withdrawal symptoms will be experienced if a dependant individual no longer consumes the drug.▫May be mild to severe depending on the drug

Research, Development, Testing of Drugs• Steps:

▫Discovery Research Identification of Lead Compounds Synthesis of Analogues Biological Testing

▫Development Research Phase I- 50-100 healthy volunteers Phase II- 200-400 patients Phase III- 3000+ patients: double blind study

▫Regulatory Review▫Post-Marketing Monitoring

Thalidomide• Prescribed for

morning sickness in early pregnancy during the 50’s and 60’s.

• Resulted in severe birth defects.

• Several years before drug was linked with malformations.

Vioxx

Remember…..

•All drugs are poisons!

Medicine and Drugs Assignment•Groups of four will prepare presentations

on each of the following topics:▫Analgesics▫Depressants▫Stimulants▫Antibacterials▫Antivirals

•Powerpoint presentation must be uploaded to http://carverchemistry.wikispaces.com/

Project Requirements

•Powerpoint presentations must include:▫List IB objectives for topic▫Summary of key information on topic▫Images which help to clarify main points▫Practice questions from textbook.

•Provide class with a concise study sheet in which each objective is addressed.

•Prepare and review questions and answers to sample test questions on your topic from IB question bank.

Antacids: IB Objectives

•D.2.1 State and explain how excess acidity in the stomach can be reduced by the use of different bases.

Analgesics: IB Objectives• D.3.1 Describe and explain the different ways that

analgesics prevent pain.• D.3.2 Describe the use of derivatives of salicylic acid

as mild analgesics and compare the advantages and disadvantages of using aspirin and paracetamol (acetaminophen).

• D.3.3 Compare the structures of morphine, codeine, and diamorphine (heroin, a semi-synthetic opiate).

• D.3.4 Discuss the advantages and disadvantages of using morphine and its derivatives as strong analgesics.

• D.3.5 Identify other commonly used depressants and describe their structures.

Depressants: IB Objectives•D.4.1 Describe the effects of depressants.•D.4.2 Discuss the social and physiological

effects of the use and abuse of ethanol.•D.4.3 Describe and explain the techniques

used for the detection of ethanol in the breath, the blood, and urine.

•D.4.4 Describe the synergistic effects of ethanol with other drugs.

•D.4.5 Identify other commonly used depressants and describe their structures.

Stimulants: IB Objectives

•D.5.1 List the physiological effects of stimulants.

•D.5.2 Compare amphetamines and epinephrine (adrenaline).

•D.5.3 Discuss the short- and long-term effects of nicotine consumption.

•D.5.4 Describe the effects of caffeine and compare its structure with that of nicotine.

Antibacterials: IB Objectives

•D.6.1 Outline the historical development of penicillins.

•D.6.2 Explain how penicillins work and discuss the effects of modifying the side-chain.

•D.6.3 Discuss and explain the importance of patient compliance and the effect of penicillin overprescription.

Antivirals: IB Objectives

•D.7.1 State how viruses differ from bacteria.

•D.7.2 Describe the different ways in which antiviral drugs work.

•D.7.3 Discuss the difficulties associated with solving the AIDS problem.

Drug Action: IB Objectives

•D.8.1 Describe the importance of geometrical isomerism in drug action.

•D.8.2 Discuss the importance of chirality in drug action.

•D.8.3 Explain the importance of the beta-lactam ring action of penicillin.

•D.8.4 Explain the increased potency of diamorphine (heroin) compared to morphine.

Drug Design: IB Objectives• D.9.1 Discuss the use of a compound library in

drug design.• D.9.2 Explain the use of combinatorial and

parallel chemistry to synthesize new drugs.• D.9.3 Describe how computers are used in drug

design.• D.9.4 Discuss how the polarity of a molecule can

be modified to increase its aqueous solubility and how this facilitates its distribution around the body.

• D.9.5 Describe the use of chiral auxillaries to form the desired enantiomer.

Mind-Altering Drug: IB Objectives•D.10.1 Describe the effects of lysergic

acid diethylamide (LSD), mescaline, psilocybin, and tetrahydrocannabinol (THC).

•D.10.2 Discuss the structural similarities and differences between LSD, mescaline, and psilocybin.

•D.10.3 Discuss the arguments for and against the legalization of cannabis.