Unit 1 Flashcards
Stage where drug is tested on animals for safety
Pre-clinical trials
Stage where drug is tested on healthy people in an inpatient setting
determine most effective administration routes and dosage ranges
Phase I
Stage where drug is tested on people with disease for which drug is intended in outpatient setting
Phase II
Stage where RCTs, double-blinded, and dose-ranging studies are performed
Phase III
Stage where post marketing data is collected
compare with other drugs on the market
long-term effects
analyze cost-effectiveness
Phase IV
At what point is a drug approved or rejected by the FDA
After Phase III
Cocaine and heroin schedule
I
Dilaudid schedule
II
Morphine schedule
II
amphetamines schedule
II
barbituates schedule
II
Methadone schedule
II
codeine schedule
3
cough medicine with codeine schedule
V
Percocet schedule
III
Benzos schedule
IV
How to write a prescription for schedule I and II drugs
paper, hand signed, specific number of pills, no refills
How to monitor adherence to therapy
lab testing
pill count
patient diary
How the body affects the drug
pharmacokinetics
How the drug affects the body
pharmacodynamics
4 phases of pharmacokinetics
- absorption
- distribution
- metabolism
- excretion
2 components of pharmacodynamics
- concentration of drug at site of action
- drug effect
therapeutic window
range of blood drug concentration that yields a sufficient therapeutic response without a toxic reaction
2 factors that affect absorption
GI motility and gastric emptying
5 factors that affect bioavailability
- first pass effect
- pro-drugs
- drug formulation (immediate vs extended release
- GI motility
- blood flow
the fraction or percentage of an administered dose of a drug that reaches the circulation in its unmetabolized form
bioavailability
250mg oral drug -> first pass-> 125mg enters blood = __ bioavailability
50%
How does gender affect pharmacokinetics
women have a high percentage of body fat which can alter the amount of drug at the site of action
hormones differ
first pass effect patho
oral drug absorbed through the alimentary canal, drugs go directly to the liver through the portal vein.
hepatic enzymes metabolize the drug, reducing the amount of active drug in the bloodstream
Pro-drugs
drugs that have no biologic activity itself, but once metabolized it becomes an active metabolite
precursor to the active drug
pro-drug
2 examples of pro-drugs
plavix and lovastatin
2 reasons for immediate release tab
quick onset
absorbs well in the acidic environment of stomach
2 reasons for enteric coating
slows drug to be dissolved in intestines rather than stomach
intestines have higher pH
helps preserve gastric mucosa
affinity
the attraction between a drug and a receptor
allosteric site
a binding site for substrates not active in initiating a response
biotransformation
metabolism or degradation of a drug from an active form to an inactive form
ligand
any chemical that interacts with a receptor
volume of distribution (Vd)
the extent of distribution of a drug in the body
high hepatic extraction ratio =>
low oral bioavailability
how does gastric emptying affect drug absorption
high rate of emptying hastens absorption and bioavailability in intestines
how does high fat meals and solid foods affect absorption
delays drugs initial delivery to intestinal absorption surfaces
how does decreased intestinal motility affect absorption and drug example
slowed peristalsis leads to greater absorption and bioavailability
prolongs contact time with intestinal surfaces (anticholinergics)
how does increased intestinal motility affect absorption and drug example
less absorption and bioavailability
shortens contact time with intestinal surfaces (laxatives)
how does blood flow affect pharmacokinetics
absorption and distribution
What route is affected by first pass effect
oral only
topical vs transdermal
topical is local absorption (does not cross the dermis)
transdermal is systemic delivery through the skin over time
examples of topical drugs
eye drops and topical steroids
3 things that affect distribution
blood flow to area
lipid vs water solubility
protein binding
protein binding pathophys
carrier proteins such as albumin bind to drug rendering it inactive or circulate unbound (free drug)
2 things that affect protein binding
affinity of drug for that protein and concentrations of both drug and protein
how does low albumin affect distribution
decreased protein binding, more free drug, higher activity of drug
drugs have higher and lower affinity for protein
drug with higher affinity may knock off a drug with lower affinity
why does INR increase when patients on coumadin take abx
abx have higher affinity for protein, knocks coumadin off protein, creating more free drug
lipid and water solubility affects
getting into the cell
phospholipid bilayer membrane acts as what
barriers, blocking or permitting the passage of various substances
Which type of compounds pass through a phospholipid bilayer readily and which has a harder time passing through?
- Hydrophobic (lipid soluble)
- Hydrophilic and ionized
4 other factors that affect distribution
- barrier integrity and strength
- size of drug molecule
- distance to travel from blood to cell
- pH
3 types of diffusion
Passive, facilitated, active
carrier proteins are utilized to transport larger molecules, from an area of higher concentration to lower
facilitated diffusion
requires energy, molecules move from lower concentration to higher concentration
active transport
metabolism
function of the body to change substances into water-soluble forms that will more readily be excreted
biotransformation of the drug from active form to inactive form
What organ is primarily responsible for metabolism
liver
phase one of metabolism
enzymatic processes that involve oxidation or reduction
drug is changed to form a more polar/water-soluble compound
hydrolysis
Phase two of metabolism
involves adding a conjugate to parent drug or phase 1 metabolized drug to further increase water solubility and enhance excretion
CVP how many enzymes are responsible for drug metabolism in 90% of cases
15
3 relationships drugs have with the CVP450 enzymatic system
substrate
inducer
inhibitor
CVP450 inducers meaning
stimulates the production of enzymes which increases the amount of enzymes available for metabolism
CYP450 inhibitors meaning
inhibits production of CYP enzymes, decreasing the metabolism of drugs and increasing circulating levels
3 drugs that induce CVP450
rifampin, phenytoin, st. johns wort
3 drugs that inhibit CVP450
grapefruit juice, azoles, protease inhibitors
3 factors that interfere with elimination
renal failure
hepatic failure
regular vs intermittent exercise
when is a drug considered fully cleared
after 4-5 half lives of the drug
how does renal failure interfere with elimination
increases the half life
how does hepatic disease interfere with elimination
impacts pro drugs and CVP450 enzymes, increases half live
how does regular vs intermittent exercise interfere with elimination
impacts blood flow, GI motility, and body temp
3 things that impact pharmacodynamics
receptor abundance (age-related)
receptor affinity (age-related)
post-receptor changes and sensitivities
4 involunatry function of ANS
thermoregulation
vascular contractility
heart and respiratory rates
digestion
2 voluntary function of SNS
movement and speech
sympathetic neurotransmitter
Norepinephrine
sympathetic receptors
Alpha 1&2
Beta 1&2
Alpha 1 receptor affects
smooth muscle
Alpha 2 receptor affects
brain, stem, spinal cord, and eye
Beta 1 receptor affects
myocardium
beta 2 receptor affects
lung
parasympathetic receptors
cholinergic and muscarinic receptors
parasympathetic neurotransmitter
ACH
What do ACH agonists do
cause contractions
increase secretions
what do anticholingercis do
block ACH
urinary retention
xerostomia
tachycardia
ED50 drug dose means
therapeutic effect in 50% of recipients
LD50 drug dose means
lethal dose in 50% of recipients
Therapeutic index =
LD50/ED50
type A adverse drug reaction
r/t pharmacologic action
side effects
mild hypersensitivity
type B adverse drug reaction
unusual or unanticipated action
hypersensitivity reaction
5 characteristics of neonatal absorption
- 80% water
- weakly alkaline gastric pH
- gastric motility differs (breastfed vs formula-fed)
- very thin stratum corneum
- poor muscle mass but great capillaries- absorption erratic
how does gastric pH affect drug absorption
degree of ionization
at what age is a child’s gastric acid output similar to an adult
2
3 differences in neonatal metabolism and excretion
low albumin
Phase I and II metabolism delayed
low GFR
decreased GI enzymes(*lipase and amylase)
until what age do you use weight-based dosing
88lbs or 18yo
5 differences in the baby population
body water content decreases
body fat increases
CVP450 starts to work
GFR increases
thin stratum corneum
At what age are the kidneys mature
2
total daily dose for peds is measured in what
mg/kg/day
What happens to blood vol in pregnancy
increases 30-50%
what happens to serum albumin in pregnancy
decreases
what happens to gastric pH in pregnancy
increases
what happens to GI motility in pregnancy
decreases (elevated progesterone)
4 factors affecting drug delivery in pregnant women
increased blood volume
decreased albumin
decreased intestinal motility
increased gastric acid
3 factors promoting transfer of drugs to the placenta or
- lipid solubility
- smaller/lighter molecules
- unbound or free drug
3 factors inhibiting transfer
- highly ionized molecules
- larger/heavier molecules
- drugs with high protein binding
controlled trials in 1st trimester without fetal harm category
A
folic acid and thyroid hormones are which category
A
no RCTs in humans, animal RCTs showed no risk in 1st or later trimesters category
B
PCN, Azithromycin, metformin, cyclobenzaprine, pantoprazole category
B
No RCTs in women or animals or animal studies showed some adverse effects category
C
ACE inhibitors, labetalol, amlodipine, gabapentin, tramadol, trazadone, and prednisone category
C
evidence of human risk, benefits must be high to warrant use category
D
sulfa drugs, ASA, losartan, benzos category
D
studies in women or animals demonstrate abnormalities, contraindicated in anyone who may become pregnant category
X
statins category
X
warfarin category
X
MTX category
X
water content in elderly
decreased
CYP450 in elderly
decreased
1/2 lives of meds in elderly
increased
Beers criteria
list of potentially inappropriate meds for use in older adults but are commonly prescribed
patients with Medicare part D may need to pay out of pocket
Appetite suppressant drugs
benzphetamine
diethylpropion
appetite suppressant mechanism of action
stimulation the hypothalamus to release NE which slows GI system
glucagon-like peptide-1 receptor agonist drug
liraglutide
lipase inhibitor drug
orlistat
Consideration with all weight-loss drugs
Schedule 3 or 4
contraindicated in pregnancy
Orlistat mechanism of action
GI pancreatic lipase inhibitor
lowers the absorption of dietary fat by 30%
liraglutide mechanism of action
- stimulates insulin secretion
- decreases glucagon secretion
- slows gastric emptying
liraglutide black box warning
can cause medullary thyroid cancer and multiple endocrine neoplasia type 2
2 combination drugs for weight management
phentermine/topiramate
naltrexone/bupropion
phentermine/topiramate contraindications and why
MAOIs, hyperthyroidism, glaucoma
stimulates release of norepinephrine, increasing BP and may lead to HTN crisis
naltrexone/bupropion boxed warning
suicidal ideation and neuropsychiatric events
2 reasons immunizations rates drop
socioeconomically disadvantaged
antivaccinators due to fear of autism
vaccination rates for 3y/o
90%
vaccination rate for 18-64 y/o
33-70%
which immunization is best for immunosuppressed kids
passive
pneumoncoccal vaccine in adults with no previous vaccine
13 valent
1 year in between
23 valent
which pneumococcal vaccine is for under 2
13
pneumococcal vaccine for over 65
23
who should receive flu vaccine
6mo and older
who shouldn’t get the flu nasal spray
immunocompromised
healthcare workers
over 50
people who live with immunocompromised people
What to do if someone has a severe reaction to vaccine
report to VAERS
contraindications to receiving vaccine
acute febrile illness
nicotine patho
bind to nicotinic receptors, central and peripheral nervous system stim, resp stim, skeletal muscle relaxation, epinephrine released, peripheral vasoconstriction, increased BP, HR, CO, and O2 consumption
how does nicotine affect dopamine
increased in CNS, stimulation the reward system
education to make sure NRT is effective
must stop smoking
education for bupropion for smoking cessation
allow to smoke for 1st week, should be weaning off by the end of the week
takes a week to have a steady state of drug in the body
how does bupropion help with smoking cessation
prevents withdraw symptoms
how does varenicline help with smoking cessation
binds to subunit of nicotinic acetylcholine receptor
activates the reward system without nicotine
naltrexone/bupropion contraindications and why
uncontrolled HTN, MAOIs (HTN crisis)
seizure disorders, bulimia, anorexia nervosa, drug/alc withdrawal (may precipitate withdrawal in opioid-dependent patients)
3 drugs FDA approved for smoking cessation
- NRT
- Bupropion SR
- Varenicline (chantix)
2 SE of bupropion SR
insomnia and dry mouth
contraindication of bupropion SR
if pt already taking wellbutrin- may lead to OD or delirium
varenicline SE
neuropsych disturbances (SI, anxiety, vivid dreams)
nausea
constipation
drowsiness
When to follow up on smoking cessation therapy pts
4 weeks after quit date
At what BMI should you recommend weight loss
> 30
25-30 with CVD risk factors (including elevated waist circumference)
At what point should pharmacotherapy be recommended for weight loss?
BMI>30
>=27 with comorbidity
who are unable to lose weight or sustain weight loss successfully
At what point should bariatric surgery be considered?
BMI>=40
or >=35 with comorbidity
unable to successfully lose weight with behavioral therapy with or without pharmacotherapy
contraindications of medications used to treat otitis externa
herpes, fungal, or viral infection
perforated eardrum
caution in pregnancy/breastfeeding
active immunization
administration or all or part of a microorganism that evokes an immune response that mimics the response of the body to natural infection
passive immunization
administration of a preformed antibody
who is passive immunization for
- patients have already been exposed or potential to be exposed to an infectious agent
- immunodeficiency
- during active disease states to help suppress the effects of a toxin or inflammatory response
2 examples of passive immunization
rabies and hep B series
How to diagnose Tobacco Use Disorder
need to meet 2 or more criteria:
1. tobacco taken in larger amounts over a longer period of time than intended
2. persistent desire to cut down or unsuccessful efforts have been made
3. significant amount of time spent on obtaining or using tobacco
4. craving exists
5. recurrent tobacco use results in failure to fulfill obligations/responsibilities
6. tobacco use continues despite it causing or contributing to arguments with others
7. tobacco use results in the individual giving up important activities
8. tobacco use recurs in physically hazardous situations
9. persistent tobacco use despite knowledge of having chronic tobacco-related physical or psychosocial problems
10. tolerance to tobacco exists (need for increased amount or diminished effect)
11. withdrawal occurs
What is the fagerstrom tolerance test
point system 0-10
time it takes for a patient to have first cigarette of the day
number of cigarettes smoked per day
what score on fagerstrom tolerance test indicates high level of physical dependence to nicotine
6-7
8-10 is VERY high
contraindications for appetite suppressants and why
patients on MAOIs, CAD, arrhythmias, heart failure, stroke, uncontrolled HTN, hyperthyroid, glaucoma
stimulates the hypothalamus to release NE which increases BP and HR, potentially leading to HTN crisis and complications with the other diseases
contraindications for lipase inhibitors and why
malabsorption syndrome, cholestasis
GI pancreatic lipase inhibitor which decreases the absorption of fat, potentially leading to too little absorption and malnutrition, GI upset, fatty stools
**may increase INR d/t decreased absorption of vitamin K
a patient’s genetics are known to affect the metabolization of what 2 drugs
Plavix and Coumadin
3 factors that promote drug transfer through the placenta
lipid solubility
smaller, lighter molecules
unbound/free drug
3 factors that inhibit drug transfer through the placenta
highly ionized molecules
larger, heavier molecules
drugs that are highly protein bound
dosing considerations in obese kids
if they weigh >40kg, weight-based dosing should be used unless it exceeds he recommended adult dose
gastric emptying in neonates and infants
prolonged and can result of regurgitation of PO meds and irregular absorption
breast-fed vs formula-fed infants GI system
breast-fed infants have a greater intestinal transit time and greater flora in their intestines
relative absorptive surface area in duodenum in peds
greater relative size than adults which enhances drug absorption
rectal absorption in young peds
drugs absorbed poorly due to poor sphincter control and frequent stools
mucosal absorption in peds
greatly effective
pulmonary absorption in peds
low Vt and increased RR which reduce drug delivery and absorption
may need adult dosing
6 factors that affect drug distribution in peds
- vascular perfusion
- body composition (water vs fat)
- tissue-binding characteristics
- physicochemical properties of the drug
- plasma protein binding
- route
neonates amount of water vs fat and effects on distribution
high water (75-80%), decreased fat
greater volume of distribution
body comp changes in infants to puberty
fat increases and total body water decreases
albumin levels in peds and how it affects distribution
decreased
increased free drug
treatment of chlamydial conjunctivitis in newborns
erythromycin
first line treatment of nongonococcal/nonchlamydial bacterial conjunctivitis
erythromycin ointment or polymyxin B trimethoprim
3 most common organisms causing bacterial conjunctivitis
staph aureus
strep pneumonias
haemophilus influenzae
second line treatment of nongonococcal/nonchlamydial bacterial conjunctivitis
ophthalmic flurorquinolone
moxifloxacin or ofloxacin
first line treatment for mild dry eye disease
artificial tears (genteal, systane)
first line treatment for moderate/severe dry eye disease
PF artificial tear substitute
first line treatment for Sjogren’s
cholinergic agonists
oral pilocarpine or cevimeline
second line treatment for dry eye disease (3)
- cyclosporine ophthalmic emulsion
- lifitegrast
- topical corticosteroids
MOA of cyclosporine ophthalmic emulsion
increase aqueous tear production, decrease ocular irritation by preventing T cells from activating and releasing cytokines
4 SE of cyclosporine ophthalmic emulsion
ocular burning
discharge
itching
blurred vision
lifitegrast MOA
block interaction of cell surface proteins LFA-1 and intracellular adhesion molecule 1 and may inhibit T cell related inflammation
2 SE of lifitegrast
taste alteration and decreased visual acuity
considerations for topical steroids
2 weeks max
long-term use is associated with ocular infection, cataract formation, and glaucoma
MOA of prostaglandin analogs
reduce IOP by improving uveoscleral outflow of aqueous humor
MOA of beta blockers for glaucoma
reduce adenylyl cyclase activity which reduces the production of aqueous humor in ciliary body
MOA of carbonic anhydrase inhibitors
Think about diamox for elevated HCO3!!
inhibits carbonic anhydrase which reduces the production of bicarb in the ciliary body. This decreases movement of sodium and water into the posterior chamber of the eye, therefore less aqueous fluid is generated
MOA of adrenergic agonists
activates the presynaptic alpha 2 receptors, inhibiting the release of NE which decreases the activated of postsynaptic beta receptors in the ciliary epithelium, reducing the formation of aqueous humor
MOA of cholinergic agonists
stimulates the parasympathetic muscarinic receptor sites to increase the outflow of aqueous humor through trabecular meshwork
MOA of Rho kinase inhibitors
increase aqueous humor outflow by relaxing cells that line Schlemm’s canal, reducing resistance
contraindications of ophthalmic beta blockers (5)
sinus brady
heart block
CHF
cardiogenic shock
severe COPD and asthma (nonselective agents)
SE of ophthalmic beta blockers (7)
bradycardia
hypotension
worsening CHF
heart block
bronchospasm
hallucination
depression
important patient education regarding glaucoma ophthalmic solutions (5)
wash hands
remove contacts
apply to inner aspect of lower eyelid
don’t let tip of container touch any part of the eye
separate drops by at least 10 mins
dosing of amoxicillin and amoxicillin-clav for children with acute otitis media
80-90mg/kg/day PO BID
dosing of ceftriaxone for children with acute otitis media
50 mg/kg/day IM qd 1-3 days
dosing of cefdinir for children with acute otitis media
14mg/kg/day PO BID
dosing of cefpodoxime for children with acute otitis media
10mg/kg/day PO QD
dosing of cefuroxime for children with acute otitis media
30mg/kg/day PO BID
duration of abx for children <2 with acute otitis media
10 days
duration of abx for children 2-5 with acute otitis media
7 days
duration of abx for children >6 with acute otitis media
5 days
otitis media first line treatment
high dose amox
after 48-72 hours of obs if >6mo
otitis media 2nd line treatment
augmentin
ceftriaxone IM if augmentin fails
otitis externa first line treatment
fluroquinolone gtts (ofloxacin vs ciprofloxacin-dex)
otitis externa second line treatment
neomycin/polymixin gtts
otitis media treatment of PCN allergy
cephalosporins:
cefuroxime
cefinir
cefpodoximine
ceftriaxone (if unable to take PO or treatment failure)
2 medications no longer recommended d/t ineffectiveness for otitis media
NO MYCINS
macrolides (azithromycin, clarithromycin, and erythromycin) and clindamycin
treatment for bacterial blepharitis
erythromycin ointment
standard treatment for blepharitis (nonpharm)
eyelid hygiene and warm compresses
erythromycin ointment contraindication
corneal abrasion (delayed healing)
2 SE of erythromycin ointment
ocular irritation and blurry vision
treatment of MGD blepharitis
eyelid massage and warm compress to remove excess oil, eyelid cleaner/baby shampoo
refer to eye care specialist
treatment of seborric blepharitis
refer to eye care specialist
first line treatment for glaucoma
prostaglandins
second line treatment for glaucoma
switch or add beta blocker
third line treatment for glaucoma
add carbonic anhydrase inhibitor or adrenergic agonist
prostaglandin suffix
-prost
carbonic anhydrase inhibitor suffix
-mide
adrenergic agonist suffix
-idine
nitric oxide donating prostaglandin analog drug
latanoprostene
cholinergic agonist drug
pilocarpine
rho kinase inhibitor drug
netarsudil