Nutritional Pharmacology Flashcards
1
Q
What is a Medicine?
A
“Any substance or combination of substances
presented as having properties for treating
or preventing disease in human beings.”
2
Q
Examples of analgesics
A
codeine, paracetamol, aspirin, ibuprofen
3
Q
Examples of laxatives
A
senna, bisacodyl
4
Q
Example of proton pump inhibitor
A
Omeprazole
5
Q
Example of anti-histamines
A
chlorphenamine, cetirizine
6
Q
Example of decongestants
A
pseudoephedrine
7
Q
What is a drug’s active ingredient?
A
Part of the drug that is intended to deliver its mode of action and is responsible for side effects
8
Q
Drug Terminology
A
Drug Class
Indication - what is it intended for
Contraindication - When the drug must
not be used
Side effects
Interactions - A drug’s activity is affected by another
substance causing an increase, decrease or a new effect.
9
Q
What is pharmacokinetics?
A
Movement of drugs within the body
10
Q
What is pharmacodynamics?
A
How drugs interact with the body to
exert their effect
11
Q
What are the 4 key processes in pharmacokinetics?
A
Absorption
Distribution
Metabolism
Elimination
(ADME).
12
Q
What is First Pass Hepatic Metabolism?
A
Drugs that are taken orally are absorbed from the GIT and taken via the portal vein into the liver to be metabolized. This means the drug concentrations can be reduced by the time they enter the systemic circulation
13
Q
What are the two main factors that determine whether a drug reaches its target site of action in the body?
A
Bioavailability
Route of administration — how a drug
is administered e.g., oral tablets, sublingual
14
Q
Examples of drug administration?
A
Oral
Sublingual/Buccal - bypasses liver metabolism
Topical
Parenteral - injections
15
Q
What factors affect drug metabolism related to the body?
A
Gastro-intestinal motility: Diarrhoea increases motility and reduces absorption.
Malabsorption states reduce absorption e.g., Coeliac disease.
Presence of other substances: E.g., absorption of iron is reduced when given with milk
16
Q
What factors affect drug metabolism related to the medicine?
A
Absorption is greatest for lipid soluble and small molecule drugs.
Acidic drugs absorb quicker in
an acidic environment e.g., stomach.
A liquid medicine will absorb quicker than a solid tablet
17
Q
How can drug distribution be affected in the body?
A
Binding to plasma proteins
Binding to other tissues
Accumulation in lipids e
Natural barriers to distribution
18
Q
What is Phase I in drug metabolism?
A
Drug / toxin is altered chemically to make
it suitable for Phase II reactions or for excretion.
Involves the cytochrome P450 enzyme family.
19
Q
What is Phase II in drug metabolism?
A
Molecules from Phase I (or in some
cases unchanged drugs) are conjugated to a more water-soluble product and aid excretion
20
Q
What are the main routes of drug excretion?
A
Urine
Faeces
21
Q
What are the minor routes of drug excretion?
A
Exhaled air
Sweat
Saliva
Tears
22
Q
What Affects Pharmacodynamics? (how drugs interact in the body to exert their effects)
A
Advancing age
Genetic mutations
Malnutrition
Medical conditions e.g., Parkinson’s disease, Alzheimer’s disease.
23
Q
What are the side of effects of PPI usage?
A
Bone fractures.
Hypomagnesaemia (low blood magnesium).
Vitamin B12 deficiency.
Bacterial enteric infections
Rebound acid hypersecretion (when PPI is stopped).
Kidney disease.
Dementia.
24
Q
Which other substances can interact with drugs?
A
Drugs.
Herbal medicines.
Food and drinks.
Nutritional supplements.
Environmental chemical agents
25
What are Narrow Therapeutic Index (NTI) drugs?
Drugs that may become dangerously toxic
or ineffective with only relatively small
changes in their blood concentrations.
26
Examples of Narrow Therapeutic Index (NTI) drugs
Digoxin
Phenytoin,
Theophylline
Warfarin
Lithium
27
What drugs can Garlic interact with?
Cholesterol and blood pressure drugs
28
What drugs can Gingko interact with?
Should be avoided with any antiplatelet and anti-coagulant medication.
29
What drugs can Grapefruit & Pomegranate interact with?
Selectively inhibits CYP3A4 in the
intestinal wall for up to 24 hours, but
NOT in the liver.
Caution is advised drugs that are metabolised via this pathway -
CYP 3A4 is involved in the
metabolism of over 50% of all drugs.
30
What drugs do green vegetables interact with?
Anticoagulants such as warfarin.
31
What compounds in green vegetables increase the metabolism of warfarin?
They contain indoles which increase
the metabolism of warfarin, and also
contain vitamin K, which reduces the
anti-clotting effects of warfarin
32
What drugs do Soy interact with?
Decreases absorption of levothyroxine:
May also interfere with oestrogen-blocking drugs
May reduce the effectiveness of warfarin
33
What drugs do dairy / calcium interact with?
Calcium can bind to antibiotics like the quinolones and tetracycline
Reduces levothyroxine absorption
34
What nutrients are depleted by PPI's?
Beta-carotene, calcium
chromium, iron, magnesium,
folate, vit. B12, vit. C, zinc.
35
How are nutrients depleted with PPI's?
Reduced gastric acid levels inhibit
absorption.
36
What nutrients are depleted by Steroids
(Prednisolone)?
Calcium, vit. D, chromium, folic acid, magnesium, potassium, strontium, zinc.
37
What nutrient is depleted by Statins?
CoQ10
38
How is CoQ10 depleted by statins?
Block synthesis of mevalonic acid, which is a precursor of cholesterol and coenzyme
Q10.
39
What nutrients are depleted by antibiotics?
Biotin, pantothenic acid (B5), pyridoxine (B6) riboflavin (B2), thiamine (B1), vit. B12,
vit. K.
40
What nutrients are depleted by Metformin?
Vitamin B12, folate.
41
How are nutrients depleted by Metformin?
Malabsorption of B12 and B9.
42
How are nutrients depleted by antibiotics?
Destruction of normal intestinal microflora may lead to decreased production of
various B vitamins and vitamin K
43
What nutrients are depleted by Diuretics?
Calcium
Magnesium
Potassium
Folate,
vits. B1, B6, C
44
How are nutrients depleted by Diuretics?
Increased urinary loss.
45
What nutrients are depleted by Antacids?
Calcium
Iron
Chromium,
Folate.
46
How are nutrients depleted by Antacids?
Increased gastric pH may reduce
solubility and absorption.
Aluminium containing antacids can bind to
calcium preventing absorption.
47
What nutrient is depleted by Thyroxine?
Calcium
48
How is Calcium depleted by Thyroxine?
Increased bone turnover may lead to
increased urinary calcium losses.
49
Which nutrients are depleted by the Oral
contraceptive pill?
Folate
Magnesium
Vitamin B6
Vitamin B2
Vitamin B1
Vitamin A
Vitamin B12
Vitamin C
Zinc
50
How are nutrients depleted by the OCP?
Reduced absorption
Increased excretion
Increased protein binding and induction of liver enzymes.
Shift from plasma to tissues.
Reduced absorption or interference with
conversion to active form.
Reduction in activity of the thiaminedependent enzyme.
Reduced liver storage of vit. A.
Reduced B12 protein binding. Increased requirement.
51
How can alcohol can inhibit a drug's metabolism?
By competing with the drug for the
same set of metabolising enzymes
52
What are ACE Inhibitors prescribed for?
Heart failure, hypertension
53
What are the contraindications of ACE Inhibitors?
Pregnancy / breastfeeding, previous allergic reaction to ACE inhibitor
54
What are common side effects or ACE Inhibitors?
Hyperkalaemia
Postural hypotension
Constipation
Diarrhoea
Nausea
Vomiting
55
What are Specific side effects of ACE inhibitors?
They cause a persistent dry cough (due to rise in bradykinin) and angioedema.
56
What should be avoided when taking ACE inhibitors?
Avoid potassium-rich diets if not taking a drug which lowers potassium alongside (e.g., a thiazide or loop diuretic).
57
What are Statins prescribed for?
Hypercholesterolaemia (incl. familial),
Hypertriglyceridemia
Prevention of cardiovascular events in those with atherosclerotic disease or diabetes
58
Mode of action for Statins?
Competitively inhibits HMG CoA reductase
— an enzyme involved in cholesterol (and COQ10) synthesis
59
What are the contraindications of Statins?
Pregnancy, breastfeeding, liver disease
60
What are the side effects of Statins?
GIT disturbance
Headaches
Fatigue
Insomnia
Myositis (inflammation of muscles)
Statin-induced myopathy
Statin use can lead to rhabdomyolysis — the breakdown of muscle cells. This can result in kidney disease and even failure.
61
Statins and Grapefruit/Pomegranate Juice
Grapefruit juice / pomegranate juice:
Significantly increases GI absorption of CYP3A4 substrates and increases peak
levels of statins.
This combination should be completely avoided
62
What are Diuretics prescribed for?
Oedema due to heart failure, hypertension
63
What is the mode of action of Diuretics?
Inhibit reabsorption of filtrate from various sections of the nephron (i.e., increased urine output), decreasing blood volume and pressure
64
What are the contraindications of Diuretics?
Metabolic imbalances (hypokalaemia, hyponatraemia, hypercalcaemia), Addison’s disease.
65
What should be cautioned in Diuretics?
Exacerbates diabetes, gout and
SLE. Elderly are susceptible to side effects
66
What are the side effects of Diuretics?
Hypokalaemia (can be
dangerous)
Hypotension
GIT disturbance,
Impotence.
Milk-alkali syndrome may occur when thiazides are combined with large quantities of calcium carbonate!
67
What is Digoxin prescribed for?
Atrial fibrillation, heart failure
68
What is the mode of action of Digoxin?
Increases force of myocardial contraction
and reduces conductivity within the atrio-ventricular node
69
What are the contraindications of Digoxin?
Heart block, ventricular tachycardia
70
What should be cautioned in Digoxin?
Hypokalaemia and low blood magnesium
can increase the risk of toxicity from digoxin
71
What are the side effects of Digoxin?
(usually in overdose): Nausea, vomiting,
diarrhoea, loss of appetite, abdominal pain, visual disturbance, arrhythmias. The elderly are especially susceptible to side effects
72
What are the interactions with Digoxin?
Hawthorn can increase myocardial contraction.
Concomitant use may require digoxin’s dose to be reduced.
73
What are Antacids prescribed for?
Gastro-oesophageal reflux
disease (GORD), indigestion
74
What is the mode of action of Antacids
Neutralisation: acid + base = water + salt
75
What should be cautioned in Antacids?
Low gastric HCl. Overuse can result
in a rebound effect if the drug is discontinued (the acid comes back more strongly)
76
What are the side effects of Antacids?
Impaired nutrient absorption;
magnesium versions can be laxative,
aluminium versions can be constipating.
77
What are the interactions with Antacids?
Vit. D may ↑ aluminium
absorption if taken at the same time
78
What are the alternatives to taking Antacids?
Chew food well
Fluids away from meals
Demulcent / anti-inflammatory herbs ― aloe vera juice, slippery
elm, liquorice, marshmallow root
Avoid caffeine
Lose weight if needed
Stop smoking
Manage stress e.g., breathing
exercises to support a shift into a parasympathetic state
79
What are PPI's prescribed for?
Gastro-oesophageal reflux disease (GORD),
prevention of NSAID-associated ulcers, triple therapy with antibiotics for gastric / duodenal ulceration
80
What is the mode of action of PPI's?
Blocks gastric cells proton (hydrogen) pump
81
What should be cautioned in PPI's?
Liver disease, pregnancy,
breast-feeding, gastric cancer
(masks symptoms).
82
What are the side effects of PPI's
Headache, GI disturbances,
rebound gastric hypersecretion and
heartburn after discontinuation of drug.
83
What is the 5R approach to GORD management?
Remove - trigger foods (spicy, fatty, dairy, chocolate, alcohol caffeine. Stop smoking
Replace - Replace deficiencies e.g., magnesium, B12, Vitamin A (introduce a general multivitamin and mineral).
Digestive enzymes / betaine HCl / digestive bitters
Repopulate - Introduce probiotics
Repair - To protect and repair the gut lining ― use slippery elm, marshmallow, chamomile, glutamine
Rebalance - Reduce and manage stress
84
What are anti-coagulants (Warfarin)
prescribed for?
DVT, pulmonary embolism, transient ischaemic attacks
85
What is the mode of action of Warfarin?
Antagonises the effects of vitamin K — a co-factor for the production of four clotting factors
86
What are the contraindications of warfarin?
Haemophilia, cerebral thrombosis, peptic ulcers, hypertension, pregnancy
87
What should be cautioned with Warfarin?
Surgery, Liver / Kidney
impairment, breastfeeding
88
What are the side effects of Warfarin?
Haemorrhage
89
What are the interactions with Warfarin?
Major changes in diet (salads / green vegetables) and alcohol consumption can affect anticoagulant control.
Pomegranate juice increases the INR by inhibiting the CYP450 enzyme that metabolises warfarin.
High doses of vitamin E inhibit platelet
aggregation and should be avoided with warfarin
90
What is Levothyroxine prescribed for?
Hypothyroidism
91
What are the contraindications of Levothyroxine?
Thyrotoxicosis.
92
What should be cautioned with Levothyroxine?
Elderly, cardiovascular disorders
93
What are the side effects of Levothyroxine?
Headache, insomnia, tremor, anxiety, flushing
94
What are the interactions with Levothyroxine?
Oral iron and calcium supplements (and cow’s dairy) reduce the absorption of levothyroxine.
It is important
that doses are separated by at least four hours.
95
Important to note about Levothyroxine dosage
The dose should be taken 30–60 minutes pre-breakfast or caffeine-containing liquids to avoid reduced absorption
96
What are anti-depressants (SSRI's) prescribed for?
Depressive illness, post-traumatic
stress, obsessive compulsive disorder
97
What is the node of action of SSRI's?
Selectively inhibit the re-uptake
of serotonin (5-hydroxytryptamine, 5-HT)
98
What are the contraindications of SSRI's?
Poorly-controlled epilepsy.
99
What are the side effects of SSRI's?
GIT disturbance, constipation, diarrhoea, insomnia, anxiety, agitation, sexual dysfunction, reduced appetite
100
What is Seratonin Syndrome?
Associated with an excess of serotonin due to therapeutic drug use, overdose or interactions between drugs
101
How can Seratonin Syndrome occur?
When two or more drugs affecting serotonin are given at the same
time or after one serotonergic drug is
stopped and another started
102
Which supplements should NOT be combined with SSRI's?
5-HTP and St. John’s wort must not be
combined with SSRIs as the
additive effect significantly increases
the risk of serotonin syndrome
103
What are NSAIDs prescribed for?
Pain relief, inflammation, temperature reduction
104
What is the mode of action of NSAIDs?
Inhibits the activity of cyclooxygenases
(COX-1 and COX-2), thereby inhibiting prostaglandin synthesis.
105
What are the contraindications of NSAIDs?
Peptic ulceration, history of gastrointestinal
bleeding or hypersensitivity to aspirin, IBD
106
What should be cautioned with NSAIDs?
Asthma, cardiac impairment, impaired renal function
107
Important to note with NSAIDs
Coadministration with warfarin increases bleeding risk.
Concomitant use of NSAIDs with high doses of nutrients and herbs with antiplatelet activity e.g., vitamin E, garlic and turmeric, may increase the risk of bleeding
108
What are the side effects of NSAIDs?
Inhibit prostaglandins that play a role in gastric mucosal defence, increasing the risk of gastric bleeding and ulceration.
Block renal prostaglandins that normally dilate vessels in the kidneys. This can lead to reduced blood flow and oxygen supply causing acute kidney damage
109
What are alternative options for NSAIDs?
Willow Bark
Turmeric
Ginger
Boswelia
110
What are Corticosteroids prescribed for?
Asthma, eczema, IBD, hypersensitivity reactions, autoimmune conditions
111
What is the mode of action for Corticosteriods?
Modulates protein synthesis
by binding to DNA.
It stimulates the production of a glycoprotein called lipocortin, which inhibits the activity of phospholipase A2 and hence inflammatory mediators
112
What is contraindicated in Corticosteroids
Active infection, live virus vaccination
113
What are the side effects of Corticosteroids?
Long-term systemic use increases risk of Cushing’s syndrome, diabetes mellitus, osteoporosis and infections
114
Important to note about Corticosteroids
Abrupt withdrawal after a prolonged period can lead to acute adrenal insufficiency, hypotension or death
115
What are alternatives to Corticosteroids?
Anti-inflammatory diet;
nutrients and herbs that inhibit inflammatory mediators e.g., EFAs, quercetin, turmeric, ginger.
Liquorice root
