Nutritional Pharmacology - Lecture 1 Flashcards
What is a medicine
Any substance or combination of substances which may be used in, or administered to, human beings, either with a view to restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action, or to making a medical diagnosis
Restrictions definitions for:
* Prescription only (POM)
* Controlled medicines
* Pharmacy only (PO)
* General sales list (GSL)
- Prescription only (POM) — supplied only under direction of qualified healthcare professional e.g., doctor’s prescription, levothyroxine.
- Controlled medicines — special group of medicines that require extra controls e.g., codeine, morphine, Valium.
- Pharmacy only (PO) — sold by a registered pharmacy – you can visit the pharmacist do get them e.g. antifungal medication, hay fever medication
- General sales list (GSL) — can be sold via a number of outlets including supermarkets. E.g. Ibuprofen, aspirin
Why do clients choose self medication
- To treat a minor ailment e.g., a cough mixture, general aches and pains, mild headaches
- To support a chronic illness when not fully controlled by prescribed medicines e.g., ibuprofen for osteoarthritis.
Type of OTC drugs:
- Analgesics (codeine, paracetamol, aspirin, ibuprofen) => low dose aspirin to prevent the progression of CVD.
- Laxatives (bisacodyl, senna) => routinely used to prevent constipation
- Proton pump inhibitors (omeprazole) => prevent HCl production, prescribed for gastric reflux
- Cough mixtures (diphenhydramine).
- Anti-histamines (chlorphenamine, cetirizine) => during pollen season or through the year
- Decongestants (pseudoephedrine)
Name 3 types of OTC drugs clients may use:
- Analgesics (codeine, paracetamol, aspirin, ibuprofen) => low dose aspirin to prevent the progression of CVD.
- Laxatives (bisacodyl, senna) => routinely used to prevent constipation
- Proton pump inhibitors (omeprazole) => prevent HCl production, prescribed for gastric reflux
- Cough mixtures (diphenhydramine).
- Anti-histamines (chlorphenamine, cetirizine) => during pollen season or through the year
- Decongestants (pseudoephedrine)
What is the active ingredient of a drug?
- Active ingredient: This is the part of the drug that is intended to deliver its mode of action and is responsible for side effects e.g., ibuprofen to reduce inflammation
What is the inactive ingredient of a drug?
- Inactive ingredients: These alter the physical properties of the drug e.g., fillers, colouring agents, preservatives, lactose, gluten, aspartame (can create intolerance type reaction), other E numbers, aluminium (found in antiacid medication and that is a neurotoxic).
What is the issue with inactive ingredients?
Studies increasingly show that inactive ingredients can trigger allergic reactions and food intolerances.
What is a generic name and brand name of pain medication?
Generic: paracetamol (Europe), acetaminophen (US).
Brand: Panadol (UK), Tylenol (US).
Define the following drug terminologies:
- Drug class
- Indication
- Contraindication
- Side effects
- Interactions
- Drug class: Penicillin is an antibiotic (are a class of drugs and penicillin is an example of this) .
- Indication: What the drug is intended for, e.g., hypertension (high blood pressure).
- Contraindication: When the drug must not be used e.g., in pregnancy (can cross the placenta barrier), renal failure (kidney issues as drugs are excreted via the kidneys puts pressure on the tubules / or when kidney can’t excrete drugs properly can create drug build up in he body).
- Side effects: Ibuprofen can produce gastric ulcers.
- Interactions: A drug’s activity is affected by another substance causing an increase, decrease or a new effect (e.g. grapefruit juice and liver metabolism of some drugs).
What is the difference between a drug and a nutrient?
- Drugs suppress and manage symptoms: They do not target the actual underlying cause!
- Nutrients encourage the body to restore homeostasis and heal.
What is herb is aspirin derived from? What is the issue with using plant extract in drugs?
aspirin is derived from willow bark
- Willow bark contains salicin, which does not convert to salicylic acid (a gastric irritant) until it reaches the bloodstream and body tissues. It naturally reduces fever, inflammation and pain without GI side effects.
- Through research, aspirin was synthetically developed from salicylic acid. Aspirin can cause gastrointestinal bleeding, peptic ulceration and hypersensitivity!
- Willow bark contains numerous active components which influence each other and in totality contribute to its overall healing potential.
Define pharmacokinetics? Why is it important?
Movement of drugs within the body - the timed movement of any drug going into, through and out of the body.
Define pharmacodynamics? Why is it important?
How drugs interact with the body to exert their effect - make sure we do not prescribe supplements that have the same function or interact.
What are the 5 most important drug concepts?
- Pharmacokinetics
- Pharmacodynamics
- Side-effects
- drug-nutrient interaction
5 Nutrient depletion
Which factors can impact pharmacokinetics?
Age, genetics, alcohol consumption, weight loss can affect the timing (send the client back to the GP!)
What key organ can impact pharmacokinetics if impaired?
The liver
What 4 key processes are involved in pharmacokinetics?
Absorption, distribution, metabolism and elimination (ADME)
Define all the ADME in pharmacokinetics
A - absorption. To exert its action (or toxicity) internally, a drug must first enter the body and be absorbed into the bloodstream.
D - distribution. In the bloodstream, the drug can now be distributed to its target site (normally a receptor) to exert its action.
M - metabolism. 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. Reducing or changing the dugs – deactivation, activation
E - elimination. Once metabolised, excretion normally takes place via urine or bile. The route for excretion need to be open (bile, urine and stool) to avoid drug reabsorptions and side effects
What is the first pass metabolism? What does this effect means?
The process by which drugs taken orally are absorbed from the GIT and taken via the portal vein into the liver to be metabolised
The effects of this mean that drug concentrations can be reduced by the time they enter systemic circulation
What 2 factors determine whether a drug reaches its target site of action in the body?
- Bioavailability — this simply refers to the ‘proportion’ of drug that can reach the bloodstream and is, therefore, available for distribution to its intended site of action.
- Route of administration — how a drug is administered e.g., oral tablets, sublingual B12, suppository, injectables, topical creams, patches, all directly influence the medicine’s bioavailability.
Name 3 routes of administration
- Oral: Tablets, capsules, liquids (elderly and young children): Absorption is mainly via the small intestine.
- Sublingual / buccal - Bypasses liver metabolism.
- Topical:
Local effect: Creams, patches, ear and eye drops.
Systemic effect: Inhalation (rapid effects). - Parenteral: Injections: Intravenous, sub-cutaneous, intra-muscular (epi-pen).
what factor can affect drug absorption? (related to the body x3)
- Gastro-intestinal motility: Diarrhoea increases motility and reduces absorption.
- Malabsorption states reduce absorption e.g., Coeliac disease, SIBO, Chron’s disease – reduce small intestine capacity to absorb the drugs.
- Presence of other substances: E.g., absorption of iron is reduced when given with milk. Calcium and Levothyroxine.
what factor can affect drug absorption? (related to the medicine x3)
- Absorption is greatest for lipid soluble and small molecule drugs (can easily pass through our lipoids cell membrane)
- Acidic drugs absorb quicker in an acidic environment e.g., stomach. Penicillin will work better if taken with food !
- A liquid medicine will absorb quicker than a solid tablet. Easier for the guts to break down
What factors affect the distribution of a drug in the body? x4
o Binding to plasma proteins which affects the active concentration of the drug. When two drugs are given together a larger amount of unbound drugs (not bound to a plasma protein because there is not enough plasma proteins) that are metabolised very fast and therefor the drugs is not being used fully by the body. That is why certain drugs are not prescribed alongside other drugs.
o Binding to other tissues e.g., tetracycline (antibiotic – given for acne on LT and short term for gut bacterial infection) binds to calcium in bones and teeth. When the teeth are calcifying (in children) if they had tetracycline during childhood or adolescence they can have permanent stain on the teeth and probably bone issues
o Accumulation in lipids e.g., general anaesthetics. Especially with clients on a weight loss program, we want them to lose weight slowly (as they probably have a high toxic load within the fat cells and they need to detoxify efficiently as they process those fat cells
o Natural barriers to distribution e.g., blood brain barrier (endothelial barrier covered in astrocytes), placental barrier.
What is drug metabolism?
the process by which drugs are chemically changed from a lipid soluble to a more water-soluble form suitable for excretion by the kidney
What are the 2 phases of drug metabolism ?
- Phase I: Drug / toxin is altered chemically to make it suitable for Phase II reactions or for excretion. Involves the cytochrome P450 enzyme family. These enzymes de-activate drugs in order to effectively pass it to phase II
- Phase II: Molecules from Phase I (or in some cases unchanged drugs) are conjugated to a more water-soluble product and aid excretion.
What are the main routes of excretion? x2
What organ is key?
Urine, faeces. We want clients to drink water and a daily bowel movement to make sure drugs is excreted properly
Renal dysfunction can, therefore, affect the rate at which a drug / metabolite is cleared from the body.
What are the minor routes of excretion? x4
Minor excretion routes: Exhaled air, sweat, saliva, tears.
What is entero-hepatic circulation? Name 3 types of drugs like that?
Some drugs (very lipid soluble) may be re-absorbed and re-enter the portal vein. This is known as ‘entero-hepatic circulation’ and prolongs excretion times. Ibuprofen, OCP, Oral Replacement Therapy. Gut flora plays a key role in these medication to allow them to be re-absorbed – be mindful of antibiotics courses and the impact on gut flora and the impact on drugs.
What factors affect pharmacodynamics?
Factors affecting a drug’s mode of action include advancing age (can have more adverse reaction to a drug), genetic mutations, malnutrition, medical conditions e.g., Parkinson’s disease, Alzheimer’s disease
What 3 information provide pharmacodynamics and pharmacokinetics?
Mode of action and administration route.
Dosage (incl. knowledge of toxic doses).
Side effects and drug interactions.
Name 5 most common side effects?
- Nausea and vomiting – opioids like codeine/morphine at its slows down digestion. Inflammation of the liver like anti-fungal (athletes foot)
- Headache.
- Dizziness.
- Constipation.
- Diarrhoea.
- Indigestion.
- Skin rashes.
- Dry mouth. Diuretics are prescribed to people on HBP medication as side effect is swelling of the ankle. Because of the release of the urine this could make the client feel dehydrated (dry mouth)
- Insomnia. Medication for flu and common cold can contain caffeine
Name 3 side effects of LT medication and a drug example
- Nutrient deficiencies e.g., metformin and B12 deficiency. PPI can also lead to a B12 deficiency. Look for sign and symptoms of B12 deficiency.
- Metabolic effects e.g., omeprazole PPI and hypomagnesaemia -> low levels of magnesium as it inhibits absorption
- Dependence e.g., diazepam, opiate analgesics (codeine).
- Osteoporosis e.g., corticosteroids => lead to faster bone turnover and reduce the amount of calcium absorbed
- Gout e.g., thiazide diuretics => happen faster when urine is more diluted so the uric acid crystals build up more quickly
- Cardiovascular disease e.g., diclofenac (NSAID).
- Peptic ulceration e.g., NSAID long-term (especially OTC) – blood on the stool red flag to GP as there may be an ulceration of the guts…
Name 5 side effects PPI are associated with?
- Bone fractures. Impact on bones as impact absorption
- Hypomagnesaemia (low blood magnesium).
- Vitamin B12 deficiency.
- Bacterial enteric infections e.g., serious Clostridium difficile. HCl is an antimicrobial and will prevent bacterial overgrowth in the small intestine
- Rebound acid hypersecretion (when PPI is stopped). When client come off the PPI the PP will over secrete HCl and then the PP will regulate itself. Client need a heads up about this to work through the withdrawal of the PPI.
- Kidney disease.
- Dementia.
Give 3 example of PPIs
- Lansoprazole (Lanzol Relief, Solox)
- Omeprazole
- Pantoprazole (Panzop Relief)
What to do as a NT if you suspect a client is having side effects?
- Check the presenting sign / symptom against the drug in your selected resource e.g., the BNF.
- Advise the client to consult his / her GP or medical specialist.
- Ensure that the food or supplement that you recommend does not interact with the client’s drug which could then cause side effects.
Why do nutritional therapists need to know about pharmacology?
To understand the mode of action of the drug to understand the effect the drug is having on the body. Makes it easier for us to understand the side-effects and understand more clearly the type of foods and supplements that mey intercat with the client medication
What do drugs contain?
Active ingredients
Inactive ingredients
Both can cause side effects or intolerances
Aspirin salicylic active is the active component but there are fillers and binders to which client might react to like aspartame.
Compare the use of willow bark and aspirin
Willow bark and aspirin are used as a pain relief / anti inflammatory
Willow bark acts with a synergy of ingredients that work together in the body whereas aspirin as a synthetic form of the salicylic acid is abrasive to the guts. This is why aspirin has the side effect of gut ulceration but willow bark not. That is because willow bark salicylic acid is only metabolised down the digestive system
Explain how the cytochrome P450 system affects drugs (HINT: Phase 1 drug metabolism).
Enzyme systems when drugs are metabolised, they can reduce that drug (dactivated) that is made into a metabolite more readily metabolised for phase II conjugation
Define a drug interaction
An interaction occurs when the effects of one drug are altered by the co-administration of another substance. Other substances can include:
* Drugs.
* Herbal medicines.
* Food and drinks.
* Nutritional supplements.
* Environmental chemical agents
How these 4 nutrients interact with drugs?
St John’s wort, Goldenseal, Grapefruit and alcohol
- St John’s wort should not be taken with antidepressant because they have additive effects (both enhanced serotonin) !
- Goldenseal is an antibacterial and can inhibit phase 1 enzyme system CYP450 and if a client is taking a drug being broken down by this enzyme it could cause a level of toxicity or the drug could not work because not activated by the enzyme.
- Grapefruit and pomegranate juice alter how some drugs are metabolised.
- Alcohol depresses the CNS (act as a sedative), if a client take a sleeping pill with alcohol it has an additive effect - Alcohol affect the CYP450 enzyme operates and make the system work more faster and drug leaves the system faster than what they are meant to do.
What are Narrow Therapeutic Index (NTI) drugs - give one example
What should a NT do about it during consultation?
- Drugs that may become dangerously toxic or ineffective with only relatively small changes in their blood concentrations.
- Examples: Digoxin (heart failure), phenytoin (epilepsy), theophylline (asthmatic), warfarin (anticoagulant), lithium (bi-polar disorder).
- During a consultation it is essential that these medicines are clearly highlighted on case notes.
- With each follow up ask clients about their drugs if there has been any changes
Which population groups are at higher risk of serious side effects from polypharmacy?
- Patients experiencing renal and liver dysfunction (metabolism and excretion of drugs!).
- Elderly patients who take more medicines and whose renal and liver function is declining.
- Patients taking drugs for chronic long-term illnesses
e.g., same patient has epilepsy, diabetes and cardiovascular disease (think of the number of drugs administered!) – those clients are more likely to experience side-effects - Critically-ill patients. There will be known side to side interaction but the priority is to keep the patient alive.
Explain the drug nutrient interaction between garlic and blood thinners?
- Interactions have been reported with cholesterol and blood pressure drugs, such as atorvastatin, propranolol, hydrochlorothiazide or captopril.
- Garlic could theoretically interact with anticoagulant or antiplatelet drugs, but current evidence has shown that at 4g / day it has little effect on warfarin-stabilised patients.
- Garlic interspersed throughout the diet is okay, but regular, high dietary intake and / or supplements could allow for interactions.
Explain the drug nutrient interaction between Ginkgo – anti-coagulant ?
- Should be avoided with any antiplatelet and anti-coagulant medication, as it has a small potential to increase bleeding risk. It should be stopped one week before surgery.
- Due to possible CYP induction (enzymes will work faster to break down drugs), it is best to monitor with the following drugs: Benzodiazepines (sedatives), anti-epileptic medication, anti- psychotic drugs, diabetic drugs, HIV medications, omeprazole (for gastrointestinal reflux), nifedipine and talinolol (blood pressure drugs).
Explain the drug nutrient interaction of grapefruit and pomegranate?
- Selectively inhibits CYP3A4 in the intestinal wall for up to 24 hours, but NOT in the liver. Caution is advised with the many drugs that are metabolised via this pathway ― e.g., digoxin, statins. CYP3A4 is involved in the metabolism of over 50% of all drugs.
Explain the drug nutrient interaction of green vegetables?
- Large amounts of green vegetables such as broccoli, spinach, cabbage, Brussels sprouts, seem to reduce the effect of anticoagulants such as warfarin.
- They contain indoles which increase the metabolism of warfarin, and also contain vitamin K, which reduces the anti-clotting effects of warfarin. Vitamin K is a coagulant, whilst warfarin is an anti-coagulant. It would be counterproductive to put a lot of vitamin K in the diet whilst the client is on anticoagulant medication
Explain the drug nutrient interaction of soy?
- Soy decreases absorption of levothyroxine: Separate ingestion by three hours.
- Soy may also interfere with oestrogen-blocking drugs such as Tamoxifen (oestrogen blocking drug used for breast cancer by woman), due to its isoflavone (phytoestrogen) content (both positive and negative effects observed).
- Soy may reduce the effectiveness of warfarin (for stroke, thrombosis).
Explain the drug nutrient interaction of dairy calcium?
- Calcium can bind to antibiotics like the quinolones and tetracycline, and also bisphosphonates (woman with osteoporosis) reducing their absorption; reduces levothyroxine absorption (take four hours apart).
Explain the effect of high protein diets on medication?
- High protein diets may reduce the effects of theophylline (drug given to asthmatics - appears to increase renal clearance) and L-Dopa (drug for Parkinson’s disease - decreases intestinal absorption and interferes with transport from the bloodstream to the brain).
Explain the effect of high fibres diets on medication?
- High-fibre diets can reduce serum levels of tricyclic antidepressants e.g., amitriptyline (decreases intestinal absorption ― take medication away from high-fibre meals). Take the medication away from a high fibre meal
Explain the effect of low salt diets on medication?
- Salt restriction can increase serum lithium to toxic levels (sodium is involved in active transport of lithium, low levels can cause lithium to accumulate in cells).
Name 3 nutrients depleted by PPI?
What is the mechanism?
Beta-carotene, calcium chromium, iron, magnesium, folate, vit. B12, vit. C, zinc
Reduced gastric acid levels inhibit absorption.
Signs and symptoms – reduced immune functions, cognitive decline, mental fatigue, sore tongue (B12)
Name 3 nutrients depleted by Steroids (Prednisolone)?
What is the mechanism?
Calcium, vit. D, chromium, folic acid, magnesium, potassium, strontium, zinc
Increase urinary excretion, losses from bone tissue.
Look at caffeine, alcohol consumption which would make the bone issue worse
Name 3 nutrients depleted by Statins?
What is the mechanism?
CoQ10
Block synthesis of mevalonic acid, which is a precursor of cholesterol and coenzyme Q10.
Cell more at risk of free radical damage as CoQ10 is an antioxidant.
Name 3 nutrients depleted by antibiotics?
What is the mechanism?
Biotin, pantothenic acid (B5), pyridoxine (B6) riboflavin (B2), thiamine (B1), vit. B12, vit. K.
Destruction of normal intestinal microflora (for 1+ year) may lead to decreased production of various B vitamins and vitamin K.
Deficiency signs of B vitamins and Vitamin K
Name 3 nutrients depleted by Metformin?
What is the mechanism?
Vitamin B12, folate.
Malabsorption of B12 and B9.
1 in 3 diabetic taking metformin for over a year is deficient in B12. Lower folate => higher homocysteine levels which is negative on heart health
Name 3 nutrients depleted by Diuretics?
What is the mechanism?
Calcium, magnesium potassium, folate, vits. B1, B6, C.
Increased urinary loss.
Loss in Ca and Mg main lead to nerve or muscle function issues.
Name 3 nutrients depleted by Antacids?
What is the mechanism?
Calcium, iron, chromium, folate.
Increased gastric pH may reduce solubility and absorption. Aluminium- containing antacids can bind to calcium preventing absorption.
Name 3 nutrients depleted by Thyroxine?
What is the mechanism?
Calcium
Increased bone turnover may lead to increased urinary calcium losses.
