Exam 1 - Math / Interactions / Absorption Flashcards
1
Q
1 pound
A
16 ounces
2
Q
1 ton
A
2000 pounds
3
Q
1 cup
A
8 oz
4
Q
1 pint
A
2 cups
5
Q
1 quart
A
2 pints
6
Q
1 gallon
A
4 quarts
7
Q
3 base units of metric system
A
- length (m)
- volume (L)
- weight (g)
8
Q
Order of metric bases
A
Kilo Hecto Deka (Unit) Deci Centi Milli
9
Q
Abbreviation for micron
A
mc
10
Q
1 kg
A
2.2 pounds
11
Q
1 pound
A
454 grams
12
Q
1 inch
A
2.54 cm
13
Q
1 teaspoon
A
5 mls
14
Q
1 tablespoon
A
15 mls
15
Q
1 Liter
A
1.06 quarts
16
Q
Weight volume solution
A
Solid is solute
17
Q
Volume volume solution
A
Liquid is solute
18
Q
ml or cc on chart?
A
- mL
19
Q
gtt
A
Drops
20
Q
Types of syringe tips
A
- lure lock
- slip
- eccentric
- catheter
21
Q
Macrodrip
A
- fast infusion
- fluid resuscitation
- drug bolus
- potential for overdose
- bad for titration
22
Q
Microdrip
A
- good for titration
- avoids overdose
- no resuscitation
- bad for large bolus
23
Q
Isotonic solution
A
- 0.9 NaCl
- 5% Dex
24
Q
Naming of drugs
A
- Brand name = Advil
- Generic name = Ibuprofen
- Chemical name = blah blah blah
25
Q
Indications / Usage
A
- FDA-approved
- reasons why you would take drug
26
Q
Contradictions
A
- warnings
- who should not take drug
- when you shouldn’t take drug
27
Q
Drug interactions happen when:
A
- combo therapy is preferable/necessary to produce effect
- single pathology may have multiple symptoms
- may suffer from more than one pathology
- modification of drug effect when given with another drug
28
Q
Beneficial drug interaction
A
- drug combo therapy
29
Q
Harmful drug interaction
A
- adverse side effects
30
Q
Addictive interactions
A
- Adds two drug effects for overall greater effect
- doubling up
31
Q
Synergistic drug interactions
A
- bad if used together
- too much effect (overkill)
32
Q
Potentiation drug interactions
A
- one drug increases the response of another drug, which normally has lesser effect
33
Q
Adverse drug reactions (ADR)
A
- unintended side effects
- 5% of hospitalization
- tremors / bronchospasm / headache / vomiting / etc
- Not all ADRs are allergies
34
Q
Drug allergy
A
- immune mediated
- induce hypersensitivity rxn
- mild hives to anaphylactic shock
- one example of an ADR
35
Q
Pharmacokinetics
A
- what body does to a drug
- Absorption (input)
- move from admin site to plasma
- rate limiting is how fast it is dissolved
- Small / non polar / lipophillic will go through
- Distribution
- dissemination of drug through body
- bloodstream is major vehicle
- influenced by flow / solubility / protein binding
- Metabolism
- transformation into secondary components (metabolites)
- preparing drug for elimination…more water soluble
- performed by liver… cytochrome P-450 enzyme systems
- Elimination (output)
- removal via urine, bile, feces
- also via pulmonary, skin, hair, saliva, and expiration
36
Q
Pharmacodynamics
A
- what the drug does to the body
37
Q
Routes of administration
A
- determined by property of drug
- solubility
- ionization
- how fast we want it to act
- need for long term treatment
- if need to restrict to local site
38
Q
Enteral
A
- through digestive tract
- usually through mouth
- most common / safest / convenient / economical
39
Q
Parenteral
A
- through outside of digestive tract directly into circulation
- IV / IM / SC
- Good:
- drugs poorly absorbed via GI
- patients who can’t take oral drugs
- need rapid onset
- highest bioavailability
- most control over dosage
- Bad:
- irreversible
- cause pain and fear
- local tissue damage
- infections
40
Q
Sublingual
A
- under tongue
- bypass GI
- rapid absorption
41
Q
Buccal
A
- Between gums and cheek
- directly into circulation
- bypass GI
- rapid absorption
42
Q
Oral administration
A
- easily self administered
- antidote for overdose
- low stomach pH inactivated some drugs
- can use enteric coating to get to small intestine
- enteric coating good for acid unstable drugs
- most complicated absorption
43
Q
Extended release prep
A
- special coatings or ingredients that control release
- slow absorption
- prolonged duration of action
- less frequent dose (improved compliance)
- useful for short half lives
44
Q
IV
A
- drug into vein
- most common parenteral route
- rapid effect / max control
Bad:- infection
- hemolysis
- no drug recall
- ADRs
45
Q
IM
A
- directly into muscle
- aqueous solutions absorbed fast
- specialized depot preps
46
Q
SC
A
- into subcutaneous tissue of skin
- via diffusion
- slower drug onset vs IV
- constant, slow, sustained effects
- insulin
47
Q
Oral / Nasal
A
- airways and lungs
- rapid delivery
- patients with respiratory disorders
- direct delivery to site of action
48
Q
Intrathecal / Intraventricular
A
- into cerebrospinal fluid
- rapid delivery
- good if need to bypass blood-brain barrier
- epidural / antibiotics for meningitis
49
Q
Topical
A
- onto skin
- good for local effect
- acne
50
Q
Transdermal
A
- via the skin
- gets into systemic circulation
- control rate of absorption
- sustained delivery
- patches
51
Q
Rectal
A
- via rectum
- avoid stomach acid
- good to avoid vomiting
- Bad:
- erratic and variable absorption
- irritate rectum
- not well accepted route
52
Q
Rate of absorption depends on:
A
- environment
- chemical characteristics of drug
- route of admin
53
Q
Oral cavity
A
- slightly acidic
- thin epithelium / high vascularity
- bypass hepatic system (no 1st pass)
54
Q
Stomach
A
- very acidic
- folds increase SA
- no absorption
- just digestion
55
Q
Small Intestine
A
- site of absorption
- deep folds with villi and microvilli
56
Q
Large intestine
A
- little absorption (just water and Na)
- bypass hepatic system
57
Q
Absorption mechanisms from GI
A
- Passive (aqueous or lipid)
- Facilitated
- Active
- Endo/Exocytosis
58
Q
Passive diffusion
A
- most common mechanism for drugs
- [ ] gradient is driving force
- not saturable
- low specificity
- through aqueous channel pore or lipid membrane
59
Q
Fick’s law
A
- applies to aqueous and lipid
- Net diffusion = (area)([ ] gradient) / thickness of membrane
60
Q
Facilitated diffusion
A
- via transmembrane carrier proteins
- conformational change allows passage
- high [ ] to low [ ]
- no energy
- saturable
- inhibited by competitors
61
Q
Active transport
A
- drugs that resemble natural metabolites
- energy dependent
- against gradient
- saturable
- selective
- competitively inhibited
62
Q
Endo and Exocytosis
A
- for large molecules across membrane
- in or out
63
Q
Factors that influence absorption
A
- pH
- Blood flow (direct)
- intestine gets more flow so intestine is favored
- in shock… low skin flow makes SC absorption poor
- Surface area (direct)
- intestines have 1000x greater than stomach
- Contact time
- Stomach…slow emptying = decrease absorption
- intestine… slow transit time = better absorption
- P-glycoproteins
- transmembrane transport protein that pumps out drugs
- reduces drug absorption
- liver / kidneys / placenta / intestines / brain
64
Q
Acidic drugs
A
HA H+ + A-
- release a proton
- HA is drug
- acidic environment shifts rxn left
- acidic drugs more soluble in acidic pH and visa versa
65
Q
Basic drugs
A
BH+ B + H+
- accept protons
- B is drug
- basic environment shifts rxn right
66
Q
Low pKa
A
- more acidic drug is
67
Q
High pKa
A
- more basic drug is
68
Q
pH < pKa
A
- protonated form dominates
- HA and BH+
69
Q
pH > pKa
A
- deprotonated form dominates
- A- and B
70
Q
Clinical application of pH of drugs
A
- can trap in urine by ionizing them
- acidic drugs excreted faster in basic urine
- basic drugs excreted faster in acidic urine
- can also trap drugs in:
- stomach
- small intestine
- breast milk
- aqueous humor
- vaginal/prostatic secretions
71
Q
Bioavailability
A
- fraction of drug unchanged following administration
- important foe calculating drug dosages for non-IV
- determined by:
- compare plasma levels of drug after IV admin
- compare plasma levels of drug after non-IV admin
- Area under curve is extent of absorption
- %BioComp. = AUC oral / AUC IV
72
Q
Factors that influence bioavailability
A
- 1st pass hepatic metabolism
- decreases absorption if goes through 1st pass
- solubility of drug
- hydrophilic poorly absorbed
- extremely lipophilic also poor
- ideal is weak acid / weak base
- chemical instability of drug
- pH of stomach can lead to this
- Degradative enzymes in GI tract too (like on insulin)
- nature of drug formulation
- particle size
- salt form
- enteric coatings
- binders and dispersing agents
73
Q
Drug pathway
A
- 1st dissolved
- 2nd absorbed
74
Q
Bioequivalence
A
- comparable:
- Bioavailability
- Time to peak [ ]
75
Q
Pharmaceutical equivalence
A
- Bioequivalent but also:
- same amount of active drug
- same dose
- same admin route
76
Q
Therapeutic equivalence
A
- Bioequivalent
- Pharmaceutically equivalent but also:
- Comparable:
- clinical effect
- safety profile
- These are generic drugs
