Midterm 2 pt. 1 Flashcards
nutrients have a ________ dose response curve
u shaped
drugs have a ________ dose response curve
sigmoid
which is more specific, drugs or nutrients
drugs
drugs are a type of
xenobiotic
the potential for ________ exists with all drugs
drug-nutrient interaction
interaction between drugs and food are ________
bi-directional
which effects are more subtle, drugs or nutrients?
nutrients
nutrients and oral drugs share
the same metabolic processes and can have overlapping molecular targets
a drug-nutrient interaction is clinically significant if
it alters the therapeutic drug response or compromises nutrition status
pharmacokinetics include
absorption, distribution, metabolism, excretion
patient outcome can be measured by
nutrition status (improved or worsened), or drug effect (toxic/ineffective or optimal)
physiologic outcome can be measured by
change in bioavailability
change in volume of distribution
change in clearance
change in biomarkers
what is a drug?
any chemical used for prevention, treatment of symptoms, or cure of disease
foods/supplements and enteral feedings are
oral (PO)
how is parenteral nutrition/IV administered?
intravenously (directly into the vein)
the pharmacokinetic stage consists of
absorption, distribution, metabolism, and elimination
What is ADME?
the pharmacokinetic stage: absorption, distribution, metabolism, and elimination
the pharmacodynamics stage is
the body’s physiological response to drugs
drug absorption factors that influence pharmacokinetics include
drug-associated factors
patient-associated factors
drug distribution factors that influence pharmacokinetics include
membrane permeability
plasma protein binding
depot storage
what drug metabolism factors influence pharmacokinetics
enzyme systems
what facilitates absorption of polar drug compounds into intestinal epithelial cells
membrane transport proteins
membrane transport proteins act as
gatekeepers to regulate uptake + efflux of nutrients and drugs
transport proteins are found in
many tissues, at apical and basolateral sides of cells
transport proteins transport
drugs and nutrients
what happens during first pass metabolism
most nutrients are taken up across the GI tract, and capillaries take them into the portal vein which goes directly to the liver (liver has first pass of metabolizing nutrients)
the efficiency of metabolism of a nutrient depends on
first pass metabolism (usually in liver)
metabolic reactions can transform
an active drug into a less-active/inactive form
a pro-drug (inactive or less active drug) into an active form
phase I reaction
(non synthetic) drugs are oxidized or reduced to a more polar form
phase II reaction
(synthetic) a polar group is conjugated to the drug
phase I is conducted by
cytochrome p450 enzymes (CYP P450)
phase II is conducted by
GST, QR, etc.
what reactions occur during phase 1?
oxidation
reduction
hydrolysis
acetylation
what reaction occurs during phase 2?
sulfate conjugation
glucuronide conjugation
glutathione conjugation
amino acid conjugation
list the drug excretion routes
urine, feces, exhaled air, sweat, saliva, tears, breast milk
which renal processes influence drug excretion
glomerular filtration
tubular secretion
tubular reabsorption
drug absorption may be influenced by
stomach and intestinal pH
gastric emptying and GI tract motility
absorptive capacity of cells
presence of food
presence of certain nutrients in GI lumen
achlorhydria
happens with aging & low stomach acidity and decreases drug absorption
a high fat meal will
slow gastric emptying rate
malnutrition can
damage integrity of GI enterocytes and decrease absorption
calcium will
chelate tetracycline and decrease absorption
citrus juice will
increase iron absorption
fosamax absorption is decreased by
food
levodopa absorption is decreased by
neutral amino acids in proteins
taking st. john’s wort will
decrease the absorption of HIV drugs
what drugs are affected by grapefruit juice
statins (to lower chol)
calcium blockers
immunosuppressants
what do blood thinners do?
reduce the rate at which blood clots form
people on coumadin
should eat MORE vit K (on blood thinners)
high fiber diets results in
increased excretion of fat-soluble compounds
acidic urine will cause
increased clearance of alkaline drugs (amphetamines)
alkaline urine
increased excretion of acidic drugs (phenobarbital)
unintended drugs that decrease appetite include
drugs that act on CNS & drugs for CA treatment (chemo)
intentional drugs that decrease appetite are
drugs for wt loss (anorexic agents)
anorexic agents include
adrenergic agents (wt mgmt)
serotoninergic agents
GLP-1 receptors
unintended drugs that increase appetite include
corticosteroids
intended drugs that increase appetite include
megestrol acetate
what is dysgeusia?
a condition characterized by altered taste perception
what is hypogeusia?
a condition characterized by reduced acuity of taste perception
how do drug luminal effects influence drug activity?
transit time in the gut & affects bile acid activity
what drug influences transit time in the gut
cathartic
laxatives
drugs that cause diarrhea
affecting bile activity also affects
absorption of fat, fat-soluble vitamins, carotene, & chol
antacids (such as ____________) does what?
proton pump inhibitors; changes pH of stomach and decreases absorption of calcium and B12
corticosteroids decreases
calcium absorption
what are the side effects of using alpha glucosidase inhibitors?
gastrointestinal intolerance
what do chemotherapy drugs do?
disrupt enterocyte replication
orlistat
reduces fat absorption
what do methotrexate pyrimethamine do?
competes w/ folic acid
isoniazid competes with
vit B6
corticosteroids increases
rate of gluconeogenesis in liver (hyperglycemia)
what do diuretics do?
increases urinary output & excretion of potassium
diuretics are taken for
high blood pressure
some drugs reduce
re-absorption of nutrients in renal tubule
polypharmacy
the practice of taking multiple medications daily; taking >4 meds/day
who’s most likely to have polypharmacy
old people w/ chronic dz
polypharmacy may contribute to
risk of malnutrition
what are effectors?
compound found in food (ingested molecule, modified molecule, part of molecule, general chemical)
what are targets (in the context of food)?
biological system
bioactives are
not essential, but they are necessary to optimize health
examples of phytochemicals and sources
beta carotene - carrots/squash
cellulose - most plant foods (fiber)
catechins - cocoa, apples
lignans - flax, rye
polyphenols
are protective against CA, DM, CVD, neurologic disorders
phytochemical profiles
differ in different varieties of the same plant (broccoli sprouts vs. mature)
pharmacokinetics
pharmacodynamics
ADME
physiological response
primary research
original data, experimental data
secondary research
meta-analyses systemic/narrative reviews
categories of research evidence
A - very strong evidence
B - strong evidence
C - moderate evidence
D - weak evidence
A
very strong evidence
- randomized controlled trials
- meta analyses
- large epidemiologic studies
B
strong evidence
- cohort + case-controlled studies
C
moderate evidence
- individual case studies
D
weak evidence
- anecdotal evidence
functional medicine tenets
seeks the address the root cause for each individual
functional medicine seeks balance between
mind, body, and spirit
the radial of integrative/functional medical nutrition therapy includes
food, lifestyle, environment
nutrition physical signs and symptoms
biomarkers
metabolic pathways
systems
CAM stands for
complementary and alternative medicines
complementary and alternative medicines are
not generally considered to be a part of conventional medicine
complementary medicine is used along with
used along with conventional medicine
alternative medicine is used
in place of conventional medicine
three categories of CAM
whole body/systems of medicine
mind & body practices
natural products
list examples of whole body/systems of medicine
ayurvedic medicine (yoga, meditation, herbal supplements)
traditional chinese medicine (herbal supplements, tai chi, acupuncture)
homeopathic medicine (small amounts of active substances)
examples of mind and body practices
focuses on interactions between brain, mind, body, behavior
- acupuncture, meditation, tai chi, relaxation techniques
categories of mind and body practices
meditation, yoga, acupuncture
can yoga help improve glycemic control
yes
most widely used CAM therapy in US are
natural products (herbs, vitamins, minerals)
what are the challenges of CAM
not many well designed trials
not covered by insurance
goes unreported
no standardizing
nutraceutical are
purified compound not usually associated w/ food
health claims describe
relationship between food and disease, strong robust evidence
structure function claims are
statement that describes the role a nutrient plays in maintaining a structure of the body or promoting a normal body function, not related to disease
qualified health claim are
limiting the statement, has strong but not as conclusive evidence as a health claim
what is diabetes?
group of disease characterized by high levels of blood glucose which results from problems with insulin production, action, or both
what is type 1 DM
disease where the body can’t make insulin
what is type 2 DM
disease where the body cannot use the insulin made (insulin resistance)
type 1 DM is an
autoimmune disease
type 2 DM is characterized by
either progressive decreased insulin secretion or lack of response to insulin at tissues (insulin resistance)
gestational DM is characterized be
high blood glucose developing during pregnancy
diabetes can be caused by other conditions such as
cystic fibrosis
impaired glucose tolerance is when
blood glucose levels not yet high enough for diagnosis of DM (i.e. metabolic syndrome)
GDM (gestational diabetes) poses risk to
mother and child, both during pregnancy, birth, and later in life
which lifestyle shows the greatest clinical significance of prevention of type II DM
weight reduction and physical activity
key point for type 2 DM
some insulin is around, but there may be limited response at the tissue
insulin resistance occurs
after the point when insulin binds to the receptor (many possible mechanims)
key point for type 1 DM
no insulin is around
what are the two pathways initiated by insulin
PI3K - inability to uptake glucose
Ras > MAPK > ERK - decreased gene expression, cell growth and proliferation
sources of glucose
diet, liver gluconeogenesis, kidney gluconeogenesis
insulin promotes
net storage of triglycerides
insulin inhibits
lipolysis of triglycerides
insulin signals a ___________ state
anabolic (making TGs and glycogen)
in insulin resistance, ________________ interfere with insulin signaling
inflammatory cytokines
in insulin resistance
insulin-stimulated GLUT4 glucose uptake is inhibited
lipolysis is NOT inhibited
what is the net result of insulin resistance
glucose not taken up –> FFA released instead
