1. Nutritional Pharmacology Flashcards
What types of drugs are:
Codeine
Paracetamol
Aspirin
Ibuprofen
Examples of analgesics
What types of drugs are:
Bisacodyl
Senna
Examples of laxatives
What type of drug is omeprazole?
Example of a PPI
What type of drugs are:
Cetirizine
Chlorphenamine
Examples of anti-histamines
What is the active ingredient of a drug?
Delivers the mode of action
Responsible for side effects
What is the inactive ingredient of a drug?
Alters the physical properties of the drug - colours, fillers, preservatives, lactose, gluten
What kind of reactions can inactive ingredients trigger?
Allergic reactions
Food intolerances
What is aspirin used for?
Reduces pain, fever, inflammation
What are the potential side effects of using aspirin?
GI bleeding
Peptic ulceration
Hypersensitivity
Which compound in aspirin triggers the side effects?
Salicylic acid
What is the natural alternative to aspirin?
Willow bark
Why is willow bark a better alternative to aspirin?
Contains salicin which doesn’t convert to salicylic acid
Same benefits without the side effects
What is meant by pharmacokinetics?
The timed movement of drugs into, through and out of the body
What is meant by pharmacodynamics?
How drugs interact with the body to exert their effect (mode of action)
What are the 4 key processes of pharmacokinetics?
Absorption
Distribution
Metabolism
Elimination
Why is absorption important in pharmacokinetics?
A drug must be absorbed into the bloodstream so it can exert its mode of action
Why is distribution important in pharmacokinetics?
Once in the bloodstream, the drug can now be distributed to its target site (normally a receptor) to exert its action
Why is metabolism important in pharmacokinetics?
Once the drug and receptor have interacted, the drug returns to the bloodstream and progresses to the liver to be metabolised and then eliminated from the body
Why is excretion important in pharmacokinetics?
Once metabolised, excretion normally takes place via urine or bile
What is first pass hepatic metabolism?
The process by which drugs taken orally are absorbed from the GIT and taken via the portal vein into the liver to be metabolised
What happens when a drug is extensively metabolised?
The amount of drug entering the bloodstream is greatly reduced
Effect exertion is reduced
How should drugs that are extensively metabolised by administered?
By a different route
e.g. nitro glycerine (GTN) spray for angina
Which two factors determine whether or not a drug reaches its target site of action?
Bioavailability
Route of administration
What is the bioavailability of a drug?
The proportion of the drug that can reach the bloodstream and is, therefore, available for distribution to its intended site of action
Where are drugs taken orally mainly absorbed?
SI
What are the benefits of sublingual/buccal drugs?
Bypasses liver metabolism
What factors affect drug absorption?
GI motility
Malabsorption
Presence of other substances
Format of the drug
How does the format of the drug affect absorption?
Acidic drugs absorb quicker in an acidic environment
Liquid medicines absorb quicker than a solid tablet
What factors affect drug distribution?
Binding to plasma proteins
Binding to other tissues
Accumulation in lipids
Natural barriers to distribution
What happens during drug metabolism?
The drug is changed from a lipid soluble to a more water soluble form for excretion
What happens during Phase I drug metabolism?
Drug is altered chemically to make it suitable for Phase II reactions or for excretion
Which family of enzymes are involved during Phase I metabolism?
CYP450
What happens during Phase II drug metabolism?
Molecules from Phase I (or in some cases unchanged drugs) are conjugated to a more water soluble product and aid excretion
What factors can influence the rate of metabolism in individuals?
Genetic
Environmental
What are the main excretion routes for drugs?
Urine
Faeces
What are the minor excretion routes for drugs?
Exhaled air
Sweat
Saliva
Tears
What dysfunction can affect the rate at which a drug/metabolite is cleared from the body?
Renal
What is entero-hepatic circulation?
Where very lipid soluble drugs may be reabsorbed and re-enter the portal vein
Prolongs excretion times
What factors can affect a drug’s mode of action?
Genetic mutations
Malnutrition
Medical conditions e.g. Parkinson’s, Alz
What information can pharmacokinetics and pharmacodynamics provide about a drug?
Mode of action
Administration route
Dosage
Side effects
Drug interactions
Which substances can affect the effects of a drug?
Food/drink
Nutritional supplements
Herbal medicines
Other drugs
Environmental chemical agents
What are narrow therapeutic index (NTI) drugs?
Drugs that may become dangerously toxic or ineffective with only relatively small changes in their blood concentrations
What types of drugs are digoxin, phenytoin, theophylline, warfarin and lithium?
Narrow therapeutic index (NTI) drugs
Which types of drugs are essential to have highlighted on case notes?
Narrow therapeutic index (NTI) drugs
Which populations are at an increased risk of serious side effects from drugs?
Patients experiencing liver/renal dysfunction
Elderly who take more than one drug
Patients taking drugs for multiple chronic long-term illnesses
Critically ill patients
What kinds of drugs can garlic interact with?
Cholesterol
Blood pressure
How should garlic be consumed to avoid interactions?
Interspersed throughout diet
Regular, high dietary intake and/or supplements should be avoided
What kinds of drugs can gingko interact with?
Anti-platelet
Anti-coagulant
(potential to increase bleeding risk)
Why should grapefruit and pomegranate be avoided with certain drugs?
Inhibits CYP3A4 in intestinal wall for up to 24 hrs
Increases peak levels of statins
Examples of drugs where grapefruit should be avoided
Statins
Digoxin
What types of drugs do green vegetables interact with?
Anti-platelet
Anti-coagulant
(potential to increase bleeding risk)
How do green vegetables interact with anti-coagulation/platelet drugs e.g. warfarin?
Reduces the effect of the drug
Contain indoles which increase the metabolism of warfarin
Also contain vit K which reduces the anti-clotting effects of warfarin
(vit K = coagulant; warfarin = anti-coagulant)
What types of drugs does soy interact with?
Thyroid (levothyroxine)
Oestrogen blocking drugs (tamoxifen)
Anti-coagulants (warfarin)
How does soy interact with levothyroxine?
Decreases the absorption of the drug
How does soy interact with warfarin?
Reduces effectiveness of the drug
What types of drugs can calcium/dairy produce interact with?
Antibiotics
Bisphosphonates
Levothyroxine
How does calcium interact with antibiotics, bisphosphonates and levothyroxine?
Reduces their absorption
How can high protein diets affect medication?
Can decrease intestinal absorption of drug
Can reduce effects of a drug
How can high fibre diets (vegan, Med diet) affect antidepressants?
Reduces serum levels of the drug
(take medication at a different time to high fibre meal)
How can salt restriction affect medication?
Can increase serum lithium to toxic levels
(Na is involved in the active transport of lithium; low levels of Na can cause lithium to accumulate in cells)
Which nutrients can be depleted by PPIs?
Beta carotene
Ca
Fe
Mg
B9
B12
C
Zn
Why are nutrients depleted when taking a PPI?
Reduced gastric acid levels inhibit absorption
Natural alternatives to PPIs
Milk thistle
Slippery elm
Dandelion root
Marshmallow root
Aloe Vera gel
Which nutrients can be depleted by steroids?
Ca
D
Folic acid
Mg
K
Zn
Why are nutrients depleted when taking steroids?
Increased urinary excretion
Losses from bone tissue
Which nutrient is depleted when taking statins?
CoQ10
Why is CoQ10 depleted when taking statins?
Statins block synthesis of mevalonic acid which is the building block of cholesterol and CoQ10
Which nutrients are depleted by antibiotics?
B1, 2, 5, 6, 7, 12
K
Why are nutrients depleted when taking antibiotics?
Antibiotics can lead to the destruction of normal intestinal microflora which produce various B vits and vit K
Which nutrients are depleted by metformin?
B9 (folate)
B12
Why are nutrients depleted by metformin?
Malabsorption
Which nutrients are depleted by diuretics?
Ca
Mg
K
B1, 6, 9
C
Why are nutrients depleted by diuretics?
Increased urinary loss
Which nutrients are depleted by antacids?
Ca
Fe
B9
Why are nutrients depleted by antacids?
Increased gastric pH may reduce solubility and absorption
Al-containing antacids can bind to Ca preventing absorption
Which nutrient is depleted by thyroxine?
Ca
Why is Ca depleted by thyroxine?
Increases bone turnover which may lead to increased urinary loss
Which nutrients are depleted by the OCP?
A
B1, 2, 6, 9,12
C
Mg
Zn
Why are nutrients depleted when taking the OCP?
Reduced absorption
Increased excretion
Increased protein binding and induction of liver enzymes
Reduced liver storage of vit A
Reduced B12 protein binding
Why should alcohol be avoided when taking drugs?
Alcohol can inhibit a drug’s metabolism by competing for the same set of metabolising enzymes
This may decrease effectiveness of the drug and transform some drugs into toxic chemicals that can cause liver/organ damage
Can magnify the inhibitory effects of sedatives/narcotics at their sites of action in the brain (codeine, morphine)
Some drugs affect the metabolism of alcohol - making them more toxic
What are ACE inhibitors prescribed for?
Hypertension
Heart failure
What are common side effects of ACE inhibitors?
Persistent dry cough
Angioedema
Constipation
Diarrhoea
Nausea
Vomiting
Postural hypotension
Hyperkalaemia
What are statins prescribed for?
Hypercholesterolaemia
Hypertriglyceridemia
Prevention of CV events
What are common side effects of statins?
GI disturbance
Headaches
Fatigue
Myositis
Myopathy
Which foods interact with statins and should be avoided?
Grapefruit
Pomegranate
What is a natural alternative to statins?
Red yeast rice
(cholesterol lowering - but don’t take with statins)
What can diuretics be prescribed for?
Oedema due to heart failure
Hypertension
What are the common side effects of taking diuretics?
Hypokalaemia
Hypotension
GI disturbance
Impotence
What are natural alternatives to diuretics?
Dandelion leaf
Nettle
Marshmallow root
What is digoxin prescribed for?
Atrial fibrillation
Heart failure
What are the common side effects of digoxin?
Nausea
Vomiting
Diarrhoea
Loss of appetite
Abdominal pain
Which nutrient should be used with caution alongside digoxin?
Hawthorn
(can increase myocardial contractions so digoxin dose may need to be lowered)
What are antacids prescribed for?
GORD
Indigestion
What are the common side effects of antacids?
Impaired nutrient absorption
Laxative (if Mg version)
Constipation (if Al version)
Rebound effect from overuse
Which nutrient may increase Al uptake from an antacid?
D
Lifestyle changes to reduce indigestion
Dietary changes - avoid spicy, fatty food, caffeine
Chew well
Keep fluids away from meals
Lose weight
Stop smoking
Manage stress
What are PPIs prescribed for?
GORD
Gastric/peptic ulceration
What are the common side effects of PPIs?
Headache
GI disturbance
Rebound of acid secretion
What are the side effects of long term use of PPIs?
GI infections
SIBO - lack of acid allows bacteria to survive
Increased fracture risk - reduced Ca absorption
B12 def - HCl needed to release B12 from proteins for intestinal absorption
Low blood Mg - decreased intestinal absorption
Fe def - decreased intestinal absorption
Why shouldn’t PPIs be withdrawn suddenly?
Rebound reflux
What protocol can be used to reduce and withdraw PPIs safely?
5R protocol
What can warfarin be prescribed for?
DVT
Pulmonary embolism
(blood thinner)
What is the most common side effect of taking warfarin?
Haemorrhaging
Bruising
Which nutrients should be avoided when taking warfarin?
Vit K rich foods (dark leafy greens, broccoli) - has opposite effect to drug
High dose vit E (same action as drug so increased bleeding risk)
Pomegranate juice - slows blood clotting time
What is levothyroxine prescribed for?
Hypothyroidism
What are the common side effects of taking levothyroxine?
Tremor
Headache
Insomnia
Anxiety
Flushing
What is the typical dosing regime for levothyroxine?
30-60 minutes pre-breakfast or caffeine containing liquids to avoid reduced absorption
What nutrients should be avoided when taking levothyroxine?
Fe/Ca supplements
Cow’s dairy
(reduce the absorption of levothyroxine)
What are common side effects of anti-histamines other than sedation?
Nausea
Vomiting
Examples of natural approaches for supporting hay fever
Quercetin
(inhibits release of histamine from mast cells)
Nettle
Bee pollen
Reishi mushroom
What are SSRIs prescribed for?
Depressive illnesses
Post-traumatic stress
Obsessive compulsive disorder
What are the common side effects of taking SSRIs?
GI disturbance
Constipation
Diarrhoea
Insomnia
Anxiety
Agitation
What is serotonin syndrome?
Excess serotonin due to SSRI use, overdose or interactions between drugs
What are the common symptoms of serotonin syndrome?
Confusion
Disorientation
Exaggerated reflexes
Fever
Sweating
Which herb and nutrient should be avoided when taking SSRIs?
St John’s Wort
5-HTP
What are NSAIDs prescribed for?
Pain relief
Inflammation
Which foods should be avoided in high quantities when taking NSAIDs?
E
Garlic
Turmeric
(may increase risk of bleeding)
What are the common side effects of taking NSAIDs?
Gastric bleeding/ulceration
Acute kidney damage
Examples of natural alternatives to NSAIDs
Willow bark
Turmeric (curcumin)
Ginger
Boswellia
Anti-inflammatory diet
Quercetin
What are corticosteroids prescribed for?
Asthma
Eczema
IBD
AI conditions
What are the common side effects of using corticosteroids?
Long term use increases risk of:
Cushing’s syndrome
DM
Osteoporosis
Infections
Why is it important to not withdraw corticosteroids abruptly?
Adrenal insufficiency
Hypotension
Death
What are natural alternatives to corticosteroids?
Anti-inflammatory diet
EFAs
Quercetin
Turmeric
Ginger
What does a bulk forming laxative do?
Increases the “bulk” or weight of poo, which in turn stimulates the bowel
What does a stimulant laxative do?
Stimulates the muscles that line the gut, helping them to move poo out of anus
What are common side effects of taking laxatives?
Dehydration
Loss of potassium
What are natural alternatives as laxatives?
Flaxseeds
Chia seeds
Psyllium husks
Water
Mg citrate
Rhubarb/dandelion/burdock root
What are natural alternatives to cough mixture?
Thyme
Honey/ginger
Honey/lemon
Rosemary