Module 05 Flashcards
(253 cards)
1
Q
2 main categories of drugs in Canada
A
- prescription drugs
- non-prescription drugs
2
Q
prescription drugs
A
drugs restricted to sale by prescription only
3
Q
non-prescription drugs
A
drugs that can be sold to the general public without prescription
- includes over-the-counter (OTC) drugs
4
Q
Over-the-Counter Drugs (OTC)
A
sold without prescription based on premise that the general public is able to diagnose mild symptoms and to select appropriate agents to treat these symptoms
5
Q
Guidelines for using an OTC drug
A
- illness and/or symptoms
- adverse effects
- consultation
6
Q
illness and/or symptoms
A
mild
- serious illness should be treated by a physician
7
Q
adverse effects of OTC drug
A
if adverse effects occur, stop taking the drug immediately
- use of OTC products can have serious consequences
- can cause toxicities on their own, interactions with other drugs (herbal & prescription drugs)
8
Q
consultation
A
if in doubt , your local pharmacist can help choose an appropriate OTC drug
- self-medication with OTC drugs should not exceed 2 weeks without consulting a physician
9
Q
what controls the sale of OTC drugs?
A
Food and Drugs Act
10
Q
The Foot and Drugs Act
A
controls the safety, efficacy, advertising, and sale of these products
11
Q
Grandparenting drugs
A
process where new regulations do not applu to those products already on the market
ex. acetaminophen
- not all OTCs have been subjected to RCTs
12
Q
concerns with not doing RCTs for drugs that have been on the market for decades
A
- some of older OTC drugs may not be effective
- some older drugs have serious toxicities
ex. if acetaminophen had to undergo safety testing to become an OTC drug today, it likely wouldn’t pass
13
Q
4 key factors to consider when selecting an OTC drug
A
- proven efficacy and known toxicity
- simple formulations and ingredients
- brand vs. generic
- appropriate and effective dose
14
Q
Proven efficacy and known toxicity
A
best OTC drug for a condition will have proven efficacy for the condition and have known level of toxicity
15
Q
Simple formulations and ingredients
A
the best OTC drugs will have the simplest formation (single ingredient)
- formulations that contain multiple drugs have one drug that is effective and others of questionable efficacy
16
Q
Brand vs. generic
A
the best OTC drug will not be the brand name
- generics are usually cheaper than the name brand product and are just as effective
17
Q
Appropriate and effective dose
A
the best OTC drug will come in the appropriate dosage from (ex. liquid for children)
- will have a therapeutically effective dose of the active ingredient
18
Q
common OTC drugs
A
- internal analgesics
- antihistamines
- drugs for excess stomach acid
- decongestants
- cough suppressant
- sleeping aids
- laxatives
- antidiarrheals
- hydrocortisone cream
- sunscreen
19
Q
internal analgesics function
A
provide pain relief
20
Q
3 common OTC internal analgesics
A
- acetylsalicyclic acid (ASA)
- acetaminophen
- NSAIDs (ex. ibuprofen and naproxen)
21
Q
acetylsalicyclic acid (ASA)
A
- generic name for aspirin
- effectively relieves pain, fever (antipyretic), and inflammation
- low doses shown to prevent stroke and heart attack
22
Q
How does ASA inhibit pain, fever, and inflammation?
A
ASA inhibits the synthesis of prostaglandins, which are endogenous substances that enhance mediation of pain and fever and have a role in inflammation
23
Q
how does ASA prevent stroke and heart attack?
A
ASA inhibits platelet aggregation and hence clot formation
24
Q
Adverse effects of ASA
A
- gastric irritation
- tinnitus
- Reye’s syndrome
- allergic reactions
25
gastric irritation
1. most common toxicity of ASA
2. breaks mucosal protective barrier in stomach, leading to irritation and bleeding
26
tinnitus
ringing in the ear drums
27
Reye's syndrome
1. occurs in children when given during fever
2. rare but serious illness affecting the CNS
28
What is the drug of choice in children with fever?
acetaminophen
29
allergic reaction to ASA
rare
- people may also be allergic to tartrazine (yellow food colouring)
30
Acetaminophen
most widely used OTC analgesic, comprising more than 50% of the market
31
Mechanism of action of acetaminophen
causes inhibition of prostglandin synthetases, which are enzymes responsible for formation of prostglandins
- this inhibits pain
32
therapeutic uses of acetaminophen
effective analgesic and antipyretic
- equal in efficacy to ASA - but is not an anti-inflammatory
33
benefits of acetaminophen
1. available in liquid preparation and is thus, convenient and suitable for children and infants
2. drug of choice in cases where ASA causes gastric irritation and fever in children
- not associated with Reye's syndrome
34
acetaminophen overdose
leads to fatal liver injury
- individual usually contains 5-10 grams (20 tablets)
35
NSAIDs examples
1. Ibuprofen (Advil)
2. Naproxen (Aleve)
36
disadvantage of acetaminophen
it is found in multiple products so an individual may overdose by simultaneously using 2 or 3 cold preparations containing acetaminophen
37
Therapeutic uses of NASAIDs
1. effective analgesics, antipyretic, and anti-inflammatory
2. ibuprofen and naproxen are the most effective OTC anti-inflammatory agents available
38
is ibuprofen or ASA more effective?
a 200 mg dose of ibuprofen is more effect than a 325 mg dose of ASA
39
mechanism of action of internal analgesics
1. when tissue damage occurs, arachidonic acid is released
2. this can be converted by enzyme cyclooygenase-1 into protective prostglandins
3. can also be converted to cyclooxygenase 2 into inflammatory prostglandins
4. internal analgesics work by blocking one or both of these cyclooxygenase enzymes
5. this reduces the production of prostglandins involved in inflammation, pain and fever
6. also reduced protective prostglandins = adverse effect
40
protective prostglandins
involved in many beneficial effects
- gastroprotections
- platelet aggregation
- renal protction
- vasodilation
- bronchodilation
41
inflammatory prostglandins
cause detrimental effects
- inflammation
- pain
- fever
- decreased platelet aggregation
42
topical analgesics
topical products available for relief of pain associated with minor sprains and joint pain
ex. topical diclofenac (voltaren), has proven efficacy
43
is pain better treated with an internal analgesic or topical?
internal analgesic
44
Antihistamines
use to treat allergy symptoms such as hay fever (allergic rhinitis)
- classified into first and second-generation agents due to slight pharmacological differences
45
Mechanism of action of antihistamines
act by blocking histamine receptors, thereby inhibiting the binding of histamine to its receptor, decreasing allergy symptoms
46
histamine
one of main substances released in allergies
47
first-generation antihistamines
cause sedation and drowsiness
- ex. diphenhydramine
48
second-generation antihistamines
less sedating than first-generation
- are the preferred agents
- ex. cetirizine
49
drugs for excess stomach acid
designed to either neutralize stomach acid or decrease stomach acid secretion
50
3 main classes of drugs for excess stomach acid
1. antacids
2. H2 inhibitors
3. proton pump inhibitors (PPIs)
51
acid secretion
active process where protons (H+) are transferred into the stomach in exchange for K+
- carried out by the proton pump
52
antacids
neutralize gastric acid by an acid-base chemical reaction
53
2 main classes of antacids
1. systemic antacids
2. non-systemis antacids
54
systemic antacids
1. given orally
2. absorbed by GI tract
55
example of a systemic antacid
calcium carbonate (tums) very rapidly neutralize stomach acid and is well tolerated
- ingesting large amounts can cause hypercalcemia and systemic alkalosis
56
non-systemic antacids
1. given orally
2. not absorbed and thus do not cause systemic alkalosis
57
example of a non-systemic antacid
aluminum hydroxide coats the mucosal lining of the stomach, protecting it from the acid
58
aluminum hydroxide
1. one of most popular antacids
2. fast onset of action, but can decreased phosphate absorption, decrease absorption of other prescription drugs and cause constipation
59
without H2 receptor antagonists
when the histamine receptors in the acid secreting cells of the stomach are activated, the proton pump is further turned on and acid secretion is increased
60
H2 receptor antagonist
block the H2 receptors thereby reducing the amount of acid secreted
- free of major adverse effects, although skin rashes, headache and confusion may occur
61
are antacids or H2 receptor antagonists more effective?
H2 receptor antagonists
62
proton pump inhibitors (PPIs)
permanently bind to the proton pump, inhibiting secretion by 90% or more
- adverse effects is low and includes diarrhea, headache and abdominal pain
- only available by prescription until recently
63
what are the most effect drugs for suppressing acid secretion
protein pump inhibitors (PPIs)
64
congestion
caused by the dilation of small blood vessels, which allows fluid to leak from the vessels into spaces between cells
65
decongestants
cause constriction of blood vessels, preventing accumulation of fluid and thereby reducing congestion
66
what are the decongestants of choice?
1. a nose drop solution containing 0.5% phenylephrine
2. oral tablet of pseudoephinedrine
***long-acting preparations are the bes
67
long-term use of decongestants
leads to local irritation and chronic rhinitis
- should not exceed three days
68
common adverse effects of decongestants
rebound congestion and potential alteration of blood pressure
69
chronic rhinitis
a congested, runny nose that is long-lasting
70
cough
complex event involving signals from the bronchioles, which are processed by the cough centre in medulla of the brain
71
what kind of cough should be suppressed?
a non-productive cough
- a productive cough should not be suppressed
72
a productive cough
one that clears the airways of mucus
73
a non-productive cough
a dry cough, that is one that is not accompanies by phlegm production
74
2 types of cough suppressants
1. centrally-acting cough suppressants
2. peripheral cough suppressants
75
centrally-acting cough suppressants
block the processing of information in the brain, reducing the frequency of the cough
- codeine is present in some OTC cough suppressants
76
dextromethorphan hydrobromide (HBr)
1. an alternative OTC cough suppressant
2. some OTC preparations contain therapeutic doses of dextromethorphan HBr, but some contain lower amounts
77
peripheral cough suppressants
block the nerve endings in the throat and bronchioles, inhibiting the stimulus to cough
- camphor and methanol are added to vaporizers or rubbed on the throat and chest
78
efficacy of peripheral cough suppressants
may exert small response to inhibit peripheral nerves in the throat
- but the placebo response is likely the reason for any efficacy observed
79
what is the cough suppressant of choice?
dextromethaorphan HBr
- no codeine
80
sleep aids
help an individual fall asleep or to relieve sleeplessness
81
common sleep aid
melatonin
82
melatonin
a hormone that plays a key role in the body's internal sleep-wake cycle
- in purified drug form, can be used to combat jet lag
83
night-time preparations of OTC drugs
had added first generation antihistamines in attempt to produce sedating effects
- NyQuil, Aleve PM
84
Laxatives
increase excretion of a soft-formed stool by increasing gut motility or hydration of the stool
85
therapeutic use of laxatives
relieve constipation, prior to radiological examination, bowel surgery or for patients suffering from CVD or hemorrhoids
86
types of laxatives
1. stimulant
2. bulk-forming
3. osmotic
87
stimulant laxatives
increase motor activity of the intestine and increase secretion of mucus, water and electrolytes into intestine
ex. bisacodyl
88
adverse effects of stimulant laxatives
1. cramping
2. water and electrolyte disturbances
3. functional disturbances in the GI tract following long-term use
89
bulk-forming laxatives
swell in water to form an emollient gel or viscous solution that maintains soft stool
- may indirectly simulate peristalsis
90
osmotic laxatives
draw water into the stool, resulting in softer stool
91
when does full effect of bulk-forming and osmotic laxatives occur?
full effect for both occurs 2-3 days after therapy has begun
92
preferred bulk-forming laxatives
methycellulose
93
preferred osmotic laxatives
polyethylene glycol 3350
94
adverse effects of bulk-forming and osmotic laxatives
water and electrolyte disturbances
95
antidiarrheal agents
used to control diarrhea
- major concern with diarrhea is dehydration
96
when should antidiarrheals not be used?
1. if accompanied by fever >38.5 degree C
2. blood or mucus in the stool
97
2 classes of antidiarrheal agents
1. absorbants
2. loperamide
98
absorbants (diarrheal agents)
add bulk to the GI tract and may absorb toxins
- useful to control acute symptoms of self-limiting diarrhea
ex. pepto-bismol
99
self-limiting diarrhea
resolves on its own
- not due to infection of chronic disease
100
loperamide
synthetic opioid that does not penetrate into the CNS
- effective for mild-to-moderate non-infectious travellers diarrhea, as it inhibits cramps
101
mechanism of action of loperamide
inhibits gut motility by acting on opioid receptors in the GI tract, reducing peristaltic activity
102
non-infectious traveller's diarrhea
no fever
103
what is the antidiarrheal agent of choice?
loperamide
104
hydrocortisone cream
0.5% or 1% - topical anti-inflammatory agent used for exposure to poison ivy, poison oak, poison sumac, insect bites and any inflammatory condition
105
calamine lotion
commonly used, and gives temporary relief
- prevents itching but does not modify the inflammatory response
106
2 types of sunscreens
1. chemical
2. physical
107
chemical sunscreens
contain compounds that absorb UV rays before they can penetrate into your skin
ex. avobenzone and octisalate
108
physical sunscreens
contain minerals, such as titanium dioxide and zinc oxide, that block and scatter UV rays before they can enter lower layers of the skin
109
recommended sunscreen
broad spectrum sunscreen with an SPF greater than 30
110
broad spectrum
protection from UVA and UBA rays from the sun
111
SPF - Sun Protection Factor
indicated how many times longer can be in the sun without burning when using sunscreen compared to no sunscreen
112
antihistamines and drug-drug interactions
antihistamines are CNS depressants and interact with other CNS depressants such as sedative-hypnotics, alcohol and opioids
113
ASA and drug-drug interactions
ASA given with oral anticoagulants (blood thinners) may produce bleeding
114
ASA and anticoagulants drug-drug interactions
ASA prevents platelets from adhering to each other, which is necessary to stop a cut from bleeding
115
antacids and drug-drug interactions
since antacids change pH of stomach acid and coat the stomach lining, they interfere with the absorption of some drugs
ex. tetracyclines
116
herbal drugs
refer to plants or plant parts that are used to prevent or treat illness, or improve health
117
2 factors that drive the use of herbal products
1. general public
2. manufacturers and retailers
117
general public contributing to use of herbal products
people like the fact they are natural products - people believe they are safer than conventional or allopathic medications
118
natural chemical toxicity
natural chemicals can be toxic
- botulinum toxin, is produced naturally by a microorganism, is one of most toxic substances known to science
119
manufacturers and retailers contributing to use of herbal products
they promote these products for financial gain
- estimated 2 billion dollars annually
120
history of herbal drugs
began when morphine replaced opium
121
4 categories of medicine/herbal products
1. allopathic medicine
2. herbal medicine
3. phytopharmaceuticals
4. allopathic phytopharmaceuticals
122
allopathic medicine
refers to drugs used by mainstream medicine
- have a drug identification number (DIN)
- undergone full testing of safety and efficacy
123
herbal medicine
refers to plant products being sold to treat a condition
- do not need a DIN
- often unpurified and lack phase 3 clinical trial data
124
phytopharmaceuticals
refer to drugs obtained from plants which are purified and used at therapeutic doses with scientific evidence of efficacy and documented toxicity
125
allopathic pharmaceuticals
refer to drugs obtained and purified from plants that meet all requirements of a drug
- full safety and efficacy evaluation and DIN
126
value of plants for pharmaceuticals
1. therapeutic effects
2. raw material = increased efficacy
127
problems associated with herbals
1. lack of efficacy and safety data (lack of RCTs)
2. interpreting the literature
128
natural health products
all NHPs are regulates under the NHP regulations
- herbal remedies
- sunscreens
- vitamins and minerals
129
interpreting the literature - herbals
the literature aimed at the general public often overstates the efficacy of herbal preparations
130
Natural Medicine Comprehensive Database
- the go-to resource for evidence-based information on herbal medicines
- rates effectiveness on a scale: effective, likely effective, possibly effective, likely ineffective, possibly ineffective, or insufficient evidence to rate effectiveness
131
additional problems associated with herbals
1. lack of standardization
2. intentional adulteration
3. differing global standards
4. drug interactions with allopathic medicines
132
lack of standardization of herbals
current legislation should address the problem of quality control during manufacturing
133
intentional adulteration of herbals
the addition of substances other then the herbal
ex. inactive material and dyes to increase weight, allopathic drugs to increase effectiveness
- cocaine, NSAIDs, etc have been found in herbal products
134
differing global standards of herbals
manufacturing facilities and processes in other countries may not be inspected using same standards used in Canada
135
drug interactions of herbals with allopathic medicines
a number of drug-drug interactions occur between prescription and herbal drugs
- important to inform physicians of use of herbal medications
136
6 common herbal drugs
1. St.John's Wort
2. Aloe Vera
3. Devil's Claw
4. Panax Ginseng
5. Enchinacea
6. Valerian
137
St. John's Wort
likely effective for mild-to-moderate depression
- recommended to treat mild-to-moderate depression and to heal wounds
- less effective than other antidepressants, but superior to placebo
138
active ingredients of St. Johns Wort
hypericin and hyperforin
- have true antidepressant activity
139
toxicities of St. John's Wort
1. syndrome (confusion, agitation, shivering, fever, sweating, etc.)
2. phototoxicity
3. should not be taken with other antidepressants (serotonin syndrome risk)
4. some products contain St. John's Wort and ephedra - should be avoided due to additive CNS excitation
140
phototoxicity
the drug is deposited in the skin, and sunlight breaks down the drug causing a skin reaction or rash
141
Aloe Vera
possibly effective for cold sores and minor skin irritations
- recommended to be applied topically in a gel or cream to heal wounds and burns
142
active ingredients of Aloe Vera
mannans and anthraquinones
143
mechanism of action of Aloe Vera in wound healing
increases the microcirculation of the skin
144
adverse effects of Aloe Vera
upon ingestion, aloe vera causes diarrhea - do not ingest
145
Devil's Claw
possibly effective for osteoporosis and back pain
- recommended for many ailments ranging from migraine to kidney disease
- main use: treatment of a inflammatory conditions
146
active ingredients of Devil's Claw
class of compounds known as iridoid glycosides
- some inflammatory properties
- inactivated in acid of the stomach
147
toxicities of Devil's Claw
most common: diarrhea
148
Panax Ginseng
possibly effective for thinking and memory, erectile sydfunction, MS related fatigue, sexual arousal and reducing risk of developing influenza
149
effects of Panax Ginseng
1. enhance memory, learning, productivity, and the immune system
2. reduce blood sugar in a diabetic person
150
active ingredients of Panax Ginseng
ginsenosides and panaxosides
151
toxicities of Panax Ginseng
1. headache
2. high BP
3. bleeding
4. increase insulin levels in the blood
152
Echinacea
possibly effective for the common cold
- recommended for the prevention and treatment of common cold, wound healing, and as an anti-inflammatory agent
153
active ingredients of Enchinacea
1. enchinacein
2. cichoric acid
3. caffeic acid
154
Echinacea extracts
can stimulate T-lymphocytes (a cell-involved in immunity)
155
toxicities of enchinacea
rare
- allergic reaction is possible
- autoimmune should not use, as any effect on the immune system could make these conditions worse
156
Valerian
possibly effective for mild insomnia
- recommended for treatment of anxiety and panic attacks
157
active ingredients of Valerian
group of compounds known as valepotriates
158
toxicities of Valerians
1. liver toxicity is a significant problem
2. CNS depressant properties may impair the ability to operate a motor vehicle
159
a vitamin
a substance essential for the maintenance of normal metabolic functions, but is not made in the body and must be provided from an outside source
- exception Vit D and K
160
2 categories of vitamins
1. water-soluble
2. fat-soluble
161
water-soluble vitamins
1. Vitamin C
2. 11 vitamins in the B group
162
fat-soluble vitamins
Vitamins A, D, E, K
163
What situation warrant vitamins as dietary supplements?
1. need for increased nutrition
2. absorption disturbances
3. inadequate nutritional intake
164
vitamin supplementation - need for increased nutrition
increased nutritional requirements may be necessary during...
- periods of growth
- hard physical work
- pregnancy and chestfeeding
- menstruation
- stress
165
more severe cases where vitamins supplementation is required
1. hyperthyroidism
2. fever
3. tissue wasting disorder
4. long-term immobilization
166
vitamin supplementation - absorption disturbances
disturbances may be due to:
- prolonged diarrhea - surgery involving intestine
- liver disease
- antibiotics that alter intestinal bacteria - as Vit K and biotin require synthesis by intestinal bacteria into usable forms
167
vitamin supplementation - inadequate nutritional intake
may be associated with...
- poverty
- geography
- those with SUDs
- those on restricted diets for disease management or otherwise
168
2 approaches to vitamin therapy
2. nutritional approach
2. megavitamin approach
169
nutritional approach to vitamin therapy
individual selects a diet aimed at supplying the RDA for each vitamin, or a multivitamin preparation that supplies the RDA of each vitamin
170
megavitamin approach to vitamin therapy
individuals ingest vitamins in excess of the RDA
- few consequences
171
consequences of the megavitamin approach to vitamin therapy
1. overdosing of Vitamin B6 can cause nerve injury
- irrespective of the though that water-soluble vitamins are rapidly excreted in the urine
2. taking high doses of fat-soluble vitamins can accumulate body fat and cause severe toxic effects
172
5 main vitamins
Vitamin A, D, E, B12, and C
173
Food Sources of Vitamin A
only animal products
- liver
- milk fat
- egg yolk
***other compounds such as carotene (found in carrots), can be converted to Vitamin A
174
Functions of Vitamin A
1. growth and development
2. normal structure of the mucous membranes and epithelial cells
3. constituent of rhodopsin, required for the night vision
175
Therapeutic Uses of Vitamin A
1. Infancy
2. Pregnancy and lactation
3. treatment of acne and other skin diseases including psoriasis and skin cancers
176
Vitamin A Deficiency
can result in
1. delay of growth and development
2. night blindness
3. drying of surface of the eye
4. changes in cells lining bronchioles in lung (respiratory infection)
5. drink, thick, and horny skin
177
Excessive Intake of Vitamin A
1. dry, itchy skin
2. vomiting
3. headache
4. enlarged liver and spleen
178
Retinoids
Vitamin A derivatives
179
Why are retinoids only available by prescription?
they are associated with many serious adverse effects
- damage to unborn child
- depression
- diabetes
- liver disease
180
Food Sources of Vitamin D
1. meat
2. fish
3. mushrooms
- in several places, milk is fortified with Vitamin D
181
Function of Vitamin D
1. increases absorption of calcium and phosphate from intestine (needed for new bone formation)
2. regulates blood calcium level
3. regulates removal of calcium from older bone
182
Therapeutic Uses of Vitamin D
prevents osteoporosis
- important nutrient for bone health
183
Vitamin D Deficiency
1. can result in decreased absorption of calcium and phosphate from intestine (decreased blood calcium)
2. leads to removal of calcium from bone in an attempt to maintain blood calcium levels
- results in defective bone growth leading to rickets
184
Excessive Intake of Vitamin D
1. elevated calcium levels in blood
- may damage kidney, heart, lungs, blood vessels and skin as this is where calcium is deposited
2. cause excess removal of calcium from bone
3. fatigue
4. vomiting
5. diarrhea
6. impaired kidney function
185
Food Sources of Vitamin E
in naturally occurring tocopherols, present in vegetable oils and green leafy vegetables
186
Function of Vitamin E
1. role as antioxidant
2. protects cells in cardiovascular system and other tissues from damaging effects of free radicals
187
Therapeutic Uses of Vitamin E
treatment of premature babies with an uncommon type of hemolytic anemia
- may be due to the antioxidant effect of Vitamin E
188
Vitamin E Deficiency
rare as the tocopherols are so prevalent in our diets
- may occur in conditions of a malabsorption syndrome (Chron's disease)
189
Excessive Intake of Vitamin E
can inhibit platelet aggregation and contribute to the anticoagulant effect of warfarin
190
Food Sources of Vitamin B12 and Folic Acid
- Vitamin B12 found in meats and dairy products
- all food groups are rich in folate but green veggies, liver and yeast are especially high folate
191
Function of Vitamin B12 and Folate
work together in the synthesis of RBCs
192
Therapeutic Uses of Vitamin B12
absorption of B12 decreases with age
- as a result, many elderly may need to increase intake
193
Therapeutic Uses of Folate
RDA for folic acid increases in pregnant women to prevent deficiencies that may lead to neural tube defect in child
- all women should take this before becoming pregnant
194
Vitamin B12 Deficiency
1. alcohol misuse or malabsorption syndromes can lead to deficiency
2. if it cannot be absorbed from the intestines, a condition known as pernicious anemia can occur (RBC deficiency)
195
Folate Deficiency
1. alcohol misuse or malabsorption syndromes can lead to deficiency
2. certain drugs (oral contraceptives, anticonvulsants, folate antagonists) may result in a folate deficiency
196
Excessive Intake of Vitamin B12
no significant toxic effects
197
Excessive Intake of Folate
- considered non-toxic when taken as a supplement
- can mask undiagnosed pernicious anemia, leading to a delay in treatment
198
Food Sources of Vitamin C
fruits and vegetables
199
Function of Vitamin C
1. contributes to framework that holds cells together
2. required for formation of bone and teeth
3. functions as an antioxidant
4. helps absorb iron
200
Therapeutic Uses of Vitamin C
1. prevent and treat scurvy
2. benefit a cold for those who are working hard under hostile conditions (Armed Forces Guy)
3. antioxidant activity may be use in preventing cancer
201
Vitamin C Deficiency
scurvy
- symptoms: weakness, bruising, anemia, loose teeth, and bleeding gums
202
Excessive Intake of Vitamin C
1. diarrhea
2. formation of kidney stones
3. rebound scurvy
202
Food Additives
substances added to food to improve the appearance, texture, and storage of food
- may also be added to improve nutritive value
203
2 classes of food additives
1. unintentional
2. intentional
204
intentional food additives
substances that are added to food to improve the appearance, texture and storage of food
205
examples of intentional food additives
1. vitamins and minerals
2. flavours
3. colours
4. preservatives
5. texture agents
206
unintentional food additives
added inadvertently as a result of the growing, manufacturing and storage processes of food
- often termed contaminants
207
examples of unintentional food additives
1. fertilizers
2. pesticides
3. heavy metals
4. biohazardous contamination (hair, animal by-products, microorganisms)
208
food additives regulations Canada
all permitted food additives and their conditions of use are listed in the Lists of Permitted Food Additives
209
Why are food additive regulations more strict compared to OTC drugs?
1. typically consumed without knowledge
2. taken for a lifetime of entire population
3. healthcare professionals are not involves with food additives
4. young children are exposed
5. they are not essential for life
210
how is the risk/benefit studied for food additives?
study the toxicity in animals and then extrapolate the results to humans
211
limitations of risk/benefit study for food additives
1. extent of exposure in humans is difficult to replicate in animals
- humans are exposed their whole lives whereas animals are not
2. assumption of risk
- the assumption made is that studying high doses in animals will mimic low-dose, lifetime exposure in humans
212
food additives as carcinogens
they are carefully tested for carcinogenicity
- if positive response, the compound is not allowed as a food additive
213
function of food additives
use of additives is justified if they enhance or maintain the quality of acceptability of food
214
quantity of additives
should only be used in quantities sufficient to obtain stated ends
215
purity of food additives
should be pure
216
toxicological evaluation of food additives
should be taken and utilized to determine potential risk of food additive and whether further study in needed
217
special group and food additives
heavy drinkers and cobalt chloride
218
cobalt chloride
a compound which inhibited the heart muscles from functioning
- was added to beer to control the amount of foam
219
heavy drinkers and cobalt chloride
risk assessments determines that individuals would need to consume 24 beers every day for long periods of time to receive toxic dose of cobalt chloride
- some did (no longer added)
220
concerns with food additives
1. don't trust the use
2. can be harmful
3. children are exposed (food colourings and preservatives)
221
simple additives
1. salt
2. sugar
3. vinegar
4. herbs
5. spices
222
preservatives
keep food from spoiling
223
spaces, sweeteners, and acids
change flavour
224
5 most common types of food additives
1. flavouring
2. colours
3. texture agents
4. preservatives
5. sweeteners
225
types of flavouring agents
1. flavouring enhancers
2. essence of smoke
3. synthetic flavours
- mixtures of artificial flavours
226
evaluation of flavouring agents
many flavouring are in use and most have not been testes, but are approved due to the experience obtained over years of use
227
toxicity of flavouring agents
few toxicities
- flavour enhancer monosodium glutamate (MSG) causes tightening of muscles in face and neck, accompanied by a headache, nausea and giddiness
228
colouring agents
organic dyestuffs added to give food and appetizing appearance
- most are well evaluated
229
adverse effects of colouring agents
allergic reactions have occured to food colours
- tartazine, a yellow food colour is common
230
red food colour No. 2
been banned as if produced cancers in experimental animals when given high doses
231
texture agents
added to improve texture of impart a specific texture to a product
- found in food with high concentrations of up to 1-3% product
- little or no toxicity
232
2 examples of texture agents
1. silicates
2. emulsifying/thickening
233
silicates
added to flour and flour products to keep them free flowing
234
emulsifying and thickening agents (gums, agar)
added to a number of frozen foods (ice cream)
235
preservatives
allows for delivery of food to distant destinations and ensures the appropriate quality of food
- benefit outweighs risks
236
2 general types of preservatives
1. antibacterials
2. antioxidants
237
3 types of antibacterial additives
1. smoke
2. antibiotics
3. sodium nitrite
238
smoke - antibacterial agent
preserves food - mainly meat
- major concern: natural smoke carries small carcinogenic risk
239
antibiotics - antibacterial agent
most effect antibacterial food additive
- not used in Canada to prevent emergence of antibiotic resistant organisms
240
sodium nitrite - antibacterial agents
added to meat to impart a pleasing red colour to prepared meats and inhibit growth of Clostridium Botulinum
241
adverse effect of sodium nitrite
formation of nitrosamines, which are carcinogens
242
antioxidant food additives
prevent oxidation and thus rancidity and discolouration of foods
- improve storage and quality of the product
243
2 types of antioxidant food additives
1. water-soluble
2. lipid-soluble
244
lipid-soluble antioxidant food additives
added to foods to prevent fats from becoming rancid
- potato chips, cookies, cakes
244
water-soluble antioxidant food additives
added to foods to reduce the oxidation of carbs (ex. browning of fruit)
- ascorbic and citric acids most commonly used
245
adverse effects of lipid-soluble antioxidant food additives
some cause liver damage
- tocopheroles (Vitamin E) are also used and are less effective but lower toxicity
246
2 common sweeteners in addition to sugar
1. saccharin
2. asparatame
247
saccharin
tabletop sweetener
- was banned until 2016 when it was deemed safe
- largely replaced by asparatame
248
asparatame
in most diet pops (200-300mg exists)
249
toxicity of asparatame
1. potential carcinogen linked to primary liver cancer
2. individuals with phenylketonuria cannot tolerate phenylalanine (aa in aspartame)
249
safety threshold of aspartame
40 mg per kg of body weight
