Transcript What is a medicine or drug?

OPTION D
MEDICINES
and
DRUGS
D1: Pharmaceutical products
and short overview of the option
Outline of this option










Jan 3, 2010
Pharmaceutical products
Antacids
Analgesics
Depressants
Stimulants
Antibacterials
Antivirals
Drug action (HL)
Drug design (HL)
Mind altering drugs (HL)
Medicines and Drugs
2
Definition of a
Medicine
Any chemical substance that
Alters a physiological state
Alters mood or emotions
Alters incoming sensory sensations
Sometimes it is difficult to determine whether a
drug has any medicinal value.
The legitimate purpose of a drug is usually to
improve health.
Use of drugs in some cases is controversial.
3
What is a medicine or drug?
A substance that alters one or more
of the following:



Incoming sensory sensations
Mood or emotions
Physiological state



Jan 3, 2010
Consciousness
Activity level
Co-ordination
Medicines and Drugs
4
Categories of medicines

Infection fighters




Affecting metabolism



Hormones
Vitamins
Affecting central nervous system




Jan 3, 2010
Antiseptics
Antibiotics
Antivirals
Stimulants
Depressants
Analgesics
Anaesthetics
Medicines and Drugs
5
Placebo Effect




Jan 3, 2010
Inert substance but effective
Used as control substance
Power of suggestion
Body’s natural healing
Medicines and Drugs
6
Research on new products
1.
Tests on animals
Dose, side effects
2.
Clinical trial (phase 1)
Safety, dose range
3.
Clinical trial (phase 2)
Response, investigator bias, statistics
4.
Clinical trial (phase 3)
Extended evaluation
> 16/3620 medicines into the market in 1970
> Thalidomide: for morning sickness but deformed babies
Jan 3, 2010
Medicines and Drugs
7
Administration of drugs

Oral
convenient, absorbed at small intestines

Rectal
when not able from mouth or destroyed by acids

Inhalation
rapid, anaesthesia

Parenteral / Injection
Subcutaneous (dental, slow)
 Intramuscular (vaccinations, large V)
 Intravenous (fast, practical)

Jan 3, 2010
Medicines and Drugs
8
Lethal Dose (LD50)
= the dose of a substance in mg per Kg of body
mass, that kills 50% of sample
The smaller the LD50,
the more toxic the substance
Examples:
aspirin
nicotine
ethanol
Jan 3, 2010
Medicines and Drugs
rat: 200
rabbit: 1000
rat: 50
rat: 9000
9
Effective Dose (ED50)
= the dose of a substance in mg per Kg of body
mass, that is effective to 50% of sample
The smaller the ED50,
the more effective the substance
Examples:
Jan 3, 2010
aspirin
Medicines and Drugs
55
10
Therapeutic window
= the ratio of LD50 over ED50
The wider the window,
the safer the substance
Examples:
aspirin
therapeutic window = 200/55
Jan 3, 2010
Medicines and Drugs
11
Drug effect


Main effect (desired)
Side effects (unwanted responses)
Drug effects are relative!!
Morphine:
For pain relief, constipation is side effect
For diarrhoea, pain relief is side effect
Jan 3, 2010
Medicines and Drugs
12
Tolerance
Over time and with regular use, the user
requires larger dose of the drug to
achieve the effect originally obtained by
smaller dose



Jan 3, 2010
Increase of hazards (larger amounts)
No tolerance to side effects
If drug not taken for long time >
decrease of tolerance >
overdose
Medicines and Drugs
13
And now a short
presentation of the rest of
the topics of this option...
Jan 3, 2010
Medicines and Drugs
14
ANTACIDS





Jan 3, 2010
Why is stomach acidic?
How can we neutralize it?
What are the most common
antacids?
What are the neutralizing reactions?
With what can the antacids be
combined?
Medicines and Drugs
15
ANALGESICS




Jan 3, 2010
What are soft and strong
analgesics?
How do they prevent pain?
Aspirin versus paracetamol?
Morphine versus heroin/codeine?
Advantages – disadvantages?
Medicines and Drugs
16
DEPRESSANTS


What is their effect?
How is effect dependant on dose?
Tranquilizers
 Sedatives
 Hypnotics
 Anaesthetics



Jan 3, 2010
Ethanol (effects, detection)
Most common depressants?
Medicines and Drugs
17
STIMULANTS



What is their effect?
Adrenaline versus amphetamines
Nicotine
Short-term effects
 Long-term effects


Caffeine
Effects
 Comparison to nicotine

Jan 3, 2010
Medicines and Drugs
18
ANTIBACTERIALS





Jan 3, 2010
The discovery of penicillin
How penicillin works
Modifications of penicillin
Use and overprescription
Broad versus narrow spectrum
antibiotics
Medicines and Drugs
19
ANTIVIRALS





Jan 3, 2010
Viruses versus bacteria
How do antiviral drugs work?
What is HIV and what AIDS?
Why is it difficult to fight HIV?
(AIDS prevention methods?)
Medicines and Drugs
20
DRUG ACTION






Jan 3, 2010
Geometrical isomers can have
different pharmacological effects
Examples: CISplatin – Thalidomide
Optical isomers can have different
pharmacological effects
Examples: Thalidomide
How structural features affect the
pharmacological effect
Examples: Penicillin, heroin
Medicines and Drugs
21
DRUG DESIGN





Jan 3, 2010
Compound library
Combinatorial and parallel
chemistry
Computer aided drug design
Polarity modification
Chirality modification
Medicines and Drugs
22
MIND ALTERING
DRUGS



Jan 3, 2010
LSD, Mescaline, Psilocybin, THC
Effects similarities, differences
Legalization of cannabis
Medicines and Drugs
23