ANTH106 Lecture Notes - Lecture 5: Samurai Shodown, Hyoscyamus Niger, Acetylcholine
5 Jun 2018
School
Department
Course
Professor
ANTH6
Drug Pharmacology and Addiction/Neuropharmacology
NEUROPHARMACOLOGY
What is Pharmacology?
• The science and study of drugs and their actions
• Considers:
- Chemical and physical properties of drugs
- Biochemical, physiological and psychological effects of drugs
- Mechanism of action
- Looks at uses and adverse effects
• Knowledge of drugs and their uses in disease goes back to Hippocrates and this
formed the basis for modern pharmacology (Oswald Schmiedenberg - 'father' of
modern pharmacology: he looked at the chemical structures)
• Scientific understanding of drugs allows us to predict the pharmacological effect
Why Learn about Pharmacology?
• Zinberg - drug, set, setting
• Health economic
• Epidemiology
• Family history of diseases
• Short term of chronic illness
• Taking more than 1 type of medication
• Dieting
• Getting old
• Alcohol or smoking
• Illicit drugs use
What is a drug?
• In Medicine: substance with the potential to prevent of pure diseases, or enhance physical
or mental welfare
• In Pharmacology: Any chemical agent that alters the biochemical physiological process of
tissues or organism
• In Common usage: refers to psychoactive drugs, and sometimes to illicit drugs of which
there is non-medical use in addition to any medical use.
• A substance that is recognised or define as a drug by the Food nd Drug Administration
Issues with definitions
• Excludes herbal remedies (e.g. St John's Wort)
• Excludes foods that alter neurotransmitter levels (e.g. serotonins is a neurotransmitter in
turkey)
Sources of Drugs
• Plants: morphine, cannabis, cocaine, peyote
• Animals: insulin, heparin
• Minerals: Magnesium sulfate, Lithium
find more resources at oneclass.com
find more resources at oneclass.com
• Micro-organisms: penicillin, Psilocybin (mushrooms)
• Synthetics: Methamphetamine, analgesics
Drug information
We need to look at the:
• Nomenclature (chemical name, non proprietary name, proprietary name
• Use (whats it for)
• Dose (how much)
• Contraindications
• Precautions (e.g. age)
• Side Effects
• Interactions
• Half-Life
Therapeutic Index
• This is a 'margin of safety'
• ED50: Dose at which 50% of population found drug to be effective
• LD50: Dose at which 50% of the population found drug to be lethal
• Drug potency: ability for drug to take effect
• Drug toxicity: potential to irreversible harm to body functions
• Every drug had a 'therapeutic index'
How drugs work
Dosage --> (Pharmacokinetics) Concentration in Plasma --> (Pharmacodynamics)
Concentration at site of action --> effect
Pharmacokinetics
• What the body does to the drug
• Absorption, distribution, metabolism and excretion
• Drug properties:
- Chemical properties (lipophilic - a drug that does not like fat won't get through into
the cell)
- Forms of drugs (tablet, liquid)
• Person/situational factors
- Size
- Diet
- Consciousness
• Routes of drug administration
- Topical applications
- Oral
- Pulmonary absorption (inhalants)
- Injections
Pharmacodynamics
• What the drug does to the body
Routes of Administration
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find more resources at oneclass.com
Oral
ADVANTAGES
- Absorption pattern: variable
- Most convenient
- Economical
- Safe
DISADVANTAGES
- Need patient co-operation
- Not used for drugs that are poorly soluble or extensively metabolised by the liver
- Vomiting due to irritation of gastric mucosa
- Drug metabolised by gut enzymes
Sublingual
• Can give to unconscious patient
• Good for high lipophilic drugs
• Dissolves quickly through mucosa to vena cava (some artery or vein)
• No first pass metabolism
Suppository/enema (rectal)
• 50% will bypass liver
• Very good when patient can not take drugs orally
• Irregular absorption
• Many drugs irritate rectal mucosa
Inhalation
• Utilises gas exchange in the lungs
• very rapid absorption due to vast surface area of lungs
• Good for pulmonary illnesses e.g. asthma
Mucous Membrane
• Nasal, vaginal, colon
• Absorbed by mucous membrane
• Bypasses first pass metabolism and gastric juices
Topical
• Transdermal
• Eye
• Good for local effects
Parenteral
Subcutaneous:
- Prompt actions from solutions, slow release from repository preps
- Good for insoluble suspension and solid pellets
Intravenous
- Limitation of absorption reduced
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
What is pharmacology: the science and study of drugs and their actions, considers: Biochemical, physiological and psychological effects of drugs. Why learn about pharmacology: zinberg - drug, set, setting, health economic, epidemiology, family history of diseases, short term of chronic illness, taking more than 1 type of medication, dieting, getting old, alcohol or smoking, illicit drugs use. Issues with definitions: excludes herbal remedies (e. g. st john"s wort, excludes foods that alter neurotransmitter levels (e. g. serotonins is a neurotransmitter in turkey) Sources of drugs: plants: morphine, cannabis, cocaine, peyote, animals: insulin, heparin, minerals: magnesium sulfate, lithium, micro-organisms: penicillin, psilocybin (mushrooms, synthetics: methamphetamine, analgesics. We need to look at the: nomenclature (chemical name, non proprietary name, proprietary name, use (whats it for, dose (how much, contraindications, precautions (e. g. age, side effects, interactions, half-life. Dosage --> (pharmacokinetics) concentration in plasma --> (pharmacodynamics) Pharmacokinetics: what the body does to the drug, absorption, distribution, metabolism and excretion, drug properties:
