19. Pharmacology - Intro Flashcards
1
Q
Characteristics of allopathic therapies
A
Treats symptoms Symptom care Suppresses symptoms Toxic Invasive Adverse effects/aggravations can be severe and permanent
2
Q
Examples of allopathic therapies
A
Drugs Surgery X-rays Radiation Chemicals
3
Q
Characteristics of natural therapies
A
Treats whole person Patient care Corrects vital force of body Non-toxic Non-invasive Aggravations/healing crisis (not life threatening)
4
Q
Examples of natural therapies
A
Nutrition Herbs Essences Oils Physical therapies
5
Q
What is suppression?
A
Disappearance of an illness without having healed it
6
Q
What can suppression cause?
A
The disease to go deeper into the body
It can reappear in another form
Adverse effects
Reoccurrence
7
Q
Examples of suppressive treatments
A
NSAIDs Steroids Analgesics Anti-hypertensive medication Chemo Radiation
8
Q
Classifications of drugs
A
Anti-microbial Anti-inflammatory Analgesic Anti-convulsant Anti-cancer
9
Q
Naming conventions for drugs
A
Proprietary/Brand/Trade name e.g. Anadin, Nurofen
Generic name e.g. paracetamol
Chemical name e.g. N-acetyl-para-aminophenol
10
Q
What is indication?
A
Approved uses of disease for which the drug has been proved effective
11
Q
What is contraindication?
A
Circumstances under which the drug shouldn’t be taken
12
Q
Should aspirin be taken by asthmatics?
A
No
13
Q
What is ‘adverse effects’?
A
Additional effect on the body even at the recommended dose e.g. drowsiness
14
Q
If a patient is experiencing adverse effects from a drug, what should you do?
A
Refer back to GP
15
Q
Classifications of adverse effects
A
Predictable
Unpredictable
16
Q
What are predictable adverse effects?
A
Exaggerated physiological effect
Toxicity
17
Q
What are unpredictable adverse effects?
A
Allergy
Idiosyncratic reaction
18
Q
Adverse effects of statins
A
Reduced CoQ10 levels leading to: Muscle pain Liver dysfunction Renal failure Cataracts
19
Q
What is CoQ10?
A
Powerful antioxidant found in mitochondria
More concentrated in cells that are more active
20
Q
Examples of hypersensitivity adverse effects
A
Penicillin - nausea, vomiting, pruritus, hives
Local anaesthetics
21
Q
What is an idiosyncratic reaction?
A
Reaction to a substance specific to the sufferer
22
Q
What can cause an idiosyncratic reaction?
A
Enzymopathy
Disturbance in enzyme function
23
Q
Example of idiosyncratic reaction
A
Excessive excitement in children after taking a sedative drug
24
Q
Categories of drug interactions
A
Synergism
Antagonism
25
What is synergism?
Effect of drug increased
26
Examples of drug synergism
Painkiller combination
| Some supplements e.g. fish oils and anti-coagulation medication
27
What is antagonism?
Effect of drug decreased
28
Examples of drug antagonism
Vitamin K counteracts anti-coagulants
29
What is an iatrogenic effect?
Induced by physician/practitioner
30
Why can some interactions between orthodox medications be fatal?
Some medications block liver/intestine enzyme pathways
Some affect liver detoxification
Facilitates an iatrogenic overdose
31
Why can grapefruit juice significantly alter drug levels in the body?
Inhibits enzyme CYP 3A4 in intestinal wall
| Leads to excessive quantity of the drug
32
What does enzyme CYP 3A4 do?
Breaks down/metabolises hundreds of medications
33
Which drugs can be affected by grapefruit juice?
Statins
HRT/OCP
Anti-retrovirals
Calcium channel blockers
34
How long can the inhibition of CYP3A4 last?
Up to 24 hours
35
What impact does the lasting effects of grapefruit juice on CYP3A4 have?
Can't separate grapefruit and drugs
36
Why can the consumption of alcohol significantly interact with drugs?
Alcohol can inhibit a drug's metabolism by competing with the drug for the same set of metabolising enzymes
37
What can long-term alcohol ingestion have on drug interaction?
May activate drug metabolising enzymes, therefore decreasing the drug's availability
Diminishes the drug's effects
Can also transform some drugs into toxic chemicals that can damage the liver/other organs
38
What effects can alcohol have on sedative/narcotic drugs?
Magnify the inhibitory effects of the drugs in the brain
39
What effects can alcohol have on slow-releasing drugs?
Can force them to release faster - resulting in overdose
40
Can some herbs interact with drugs?
Yes
41
Example of St John's Wort interacting with drugs
St John's Wort reduces the effectiveness of anti-retroviral drugs for HIV
42
Examples of liquorice interacting with drugs
Digoxin - can increase adverse effects by lowering potassium levels
Interferes with ACE inhibitors and diuretics
Contraceptives - can elevate blood pressure and lower potassium
May effect breakdown of drugs in the liver
43
Examples of senna interacting with drugs
Can increase adverse effects of digoxin
Can cause diarrhoea if taken in high doses
Can increase the effect of warfarin
May cause dependence if taken long-term
44
What is pharmacokinetics?
How drugs are absorbed and moved around the body
45
What does pharmacokinetics comprise of?
Absorption
Distribution
Metabolism
Excretion
46
What is pharmacodynamics?
How drugs exert their effects e.g. block receptors
47
What factors should be considered when administering a drug?
```
Cost
Patient compliance
Bioavailability
Speed of effects
Safety
Food interactions
Ability to absorb
Whether it bypasses the liver
```
48
In what ways can drugs be administered?
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Orally
Sublingually
Injection
Inhalation
Topically
```
49
Types of oral drugs
Tablets
Capsules
Liquids
50
Where are oral drugs absorbed?
Stomach
| Intestines
51
What does the bioavailability of oral drugs depend on?
Release of the active form
Destruction in the gut
Absorption
Loss of active form via the first pass
52
Types of sublingual drugs
Nitro-glycerine (GTN)
B12
Homeopathy
53
What is the benefit of sublingual drugs?
Avoids first pass effect in the liver, so avoids becoming deactivated
54
Categories of drug injections
Intradermal
Subcutaneous
Intramuscular
Intravenous
55
Examples of drug injections
Insulin into adipose tissue
| B12
56
Examples of inhalation drugs
Bronchodilators
Anaesthetics
Essential oils
57
What do topical drugs need to be to able to penetrate the skin?
Lipid soluble
58
Examples of topical drugs
Nicotine patch
Oestradiol HRT patch
Steroid creams for psoriasis/eczema
59
Where do suppositories/pessaries go?
Rectum
| Vagina
60
What can suppositories/pessaries be used for?
Haemorrhoids
61
What is an enema?
Procedure using gas or water to extract/clean
62
Which circulatory systems do drugs enter?
Blood
| Lymphatic
63
Why do lipid-soluble substances cross cell membranes easily?
Due to the phospholipid bilayer
64
What barriers are in the body to inhibit the movement of drugs?
Placenta
| BBB
65
Why can the BBB make treating pathologies of the nervous system difficult?
Drug can work in the general circulation but can't cross into the brain
66
Which substances can cross the BBB?
Very lipophilic substances
| Substances actively transported
67
Why should care with medications be taken during pregnancy?
The placenta is much less effective than the BBB at keeping medications out
68
What is dosage?
The amount of drug required to produce the desired effect
69
How is dosage calculated?
To ensure a therapeutic concentration is maintained for the time period required
70
How is dosage usually expressed?
By a weight/measure and by time e.g. 2x BD, 3x TDS
71
What are dosage parameters?
Weight
Age
Sex
How eliminated and rate
72
What is dosage frequency based on?
Absorption
Transport
Half-life
73
What factors can influence patient compliance?
Feels better
Forgetting
Inconvenience
74
What can taking a drug too frequently or at a higher dose lead to?
Toxicity
75
What is the compliance rate for a once a day dosage regime?
95%
76
What is the compliance rate for a twice a day dosage regime?
76%
77
What is the compliance rate for a three times a day dosage regime?
75%
78
What is the compliance rate for a four times a day dosage regime?
58%
79
What is 'half-life'?
Time it takes for a drug's concentration in the body to fall by half
80
What does half-life reflect?
The rate of elimination
81
How does a long half-life affect dosage?
Take less often
82
Types of dosing regimes
Toxic dosing
Sub-optimal dosing
Therapeutic dosing
83
What is toxic dosing?
Drug given too frequently or at too high a dose
84
What is sub-optimal dosing?
Drug given too infrequently or at too low a dose
85
What is therapeutic dosing?
A dosing regime that maintains drug concentration within the therapeutic range
86
What is a loading dose?
A larger dose given initially, followed by smaller maintenance doses
87
What is the benefit of a loading dose?
Allows the drug to rapidly reach therapeutic levels
88
When can a loading dose be done?
When there are no adverse effects from taking a larger dose
89
What can affect drug absorption?
```
Large or small molecules
Lipid soluble vs water soluble
Acid vs alkaline
Chemically reactive vs chemically inert/stable
Gut health
Digestive function
Foods ingested
```
90
Characteristics of lipid soluble drugs
Get quicker into the cell
91
Characteristics of water soluble drugs
Repelled so slower getting into the cell
92
Characteristics of acid and alkaline drugs
Best absorbed in an environment that matches the drug type
| e.g. aspirin is acidic and is absorbed in the stomach (which is also acidic)
93
What happens to the metabolism of synthetic drugs?
Body won't have a natural mechanism to remove it
| It may be metabolised to render it inactive
94
Which enzyme system becomes active with exposure to certain drugs?
CYP450
95
Where do CYP450 enzymes exist?
Intestines
| Liver
96
Why are some drug metabolites toxic?
Products formed during metabolism can be hepatotoxic and deplete the liver of its natural antioxidant (glutathione)
97
Why can't some drugs be taken orally?
They are metabolised so quickly by the liver
98
Where does most drug excretion take place?
Kidneys
| Intestines
99
How do the kidneys excrete drugs?
Glomerular filtration
| Tubular secretion
100
How do the intestines excrete drugs?
Bile
101
What can also assist in drug excretion?
Lungs
| Skin
102
What are the main modes of action for drugs?
Specific
General
Placebo
103
What is a specific mode of action?
Chemical structure is paramount
104
What is a general mode of action?
Physical and chemical properties are important
105
Examples of general modes of action?
General anaesthetics blocking impulses in neurons
| Antacids neutralising stomach acid
106
What does the effectiveness of a placebo depend on?
Patient having belief in the remedy/practitioner, confidence from their consultation and the form of remedy
107
What are agonist drugs?
Bind to receptors and stimulate increased activity
108
Example of an agonist drug
Blue inhaler
109
What are antagonist drugs?
Drugs that bind to receptors and block the natural chemical from attaching and sending its message
110
Example of an antagonist drug
Betablockers
