Theraputic Drug Monitoring Flashcards
What is TDM?
Measurement of drugs and or metabolites in body fluids - usually blood- to maintain therap. benefits
Describe T.R
the dose, concentration or range of a drug within the drug produces the desired theraputic effect
Describe T.R out of range
ineffective or toxic effect
T/F most drugs require monitoring
false, most drugs dont
Important Considerations of TDM
timing of collection (important)
Accurate measurement of []
Timely reporting of results
When is TDM used
when drug has narrow T.R
marked pharmokeinetic variabilites
Critical Adverse effects
Main purpose of TDM
ID?
ensure correct dosage for the T.R
ID drug interactions if multiple drugs are taken together
Factors that affect drug concentration
Age
gender
genetics
diet
co-drugs
naturopathic
T/F: TDM can help establish dosing regimen
Can ID non-compliance or changes if needed
Based on studies pharmokin/pharmogen
TRUE
Describe Pharmokinetics
study of
provides a time?
absorb….
what place what time?
study of movement of drugs in the body
provides a time-course of drug [ ] as absorption/disturb/metabolism
Drugs at right place at right time
Describe the route of drugs intake briefly
Oral most common
IV most direct/effective
IM
Sub cutaneous
Aerosol
Rectal
Describe Bioavilability
Amount of dose that reaches site as needed
Describe drug absorption
oral efficiency
factors that influence
how does it move across the membrane?
Oral: effic. of absorb from GI tract depends on sev. factors
solubility of GI fluid
diffuse across membrane
T/F: Some drugs require active transport mechanisms like dietary consituents
true
How are most drugs absorbed? What are some things needed?
ga
Most absorbed passively through GI tract into the blood stream
Drug - hydrophobic
Gastric acidity
Gastric Acidity:
WA:
WB:
WA - efficently absorb by stomach
WB: absorbed in intestines
What are some things that affect drug absorbtion
changes in intestinal motility/pH/inflammation/food/other drugs
T/F morphine slows GI motility
true
Describe drug distribution
hint:movement of drug…
movement of a drug between blood circulation/tissues/organs and the relative proportion of drug in tissues
T/F Free fractions can not diffuse out of vasulature
False, they can diffuse out of the vasculature and into intersitial places
The ability to leave circulation depends on what?
Hydrophobic
Polar
Ionized
Lipid solubility
High hydrophobic - easily cross
Polar can cross but dont enter
Ionized diffuse out of vasculature but slowly
Volume of distribution to drug concentration
Hydrophobic
Ionized
Hydrophobic has large vol Distrib
Ionized or primary protein has small volume
Briefly describe free vs bound drugs
Active fractions
most drugs are subject to binding w serum protein (Drug-protein complex)
Only free/unbound can interact with site of action/bioresponse (Active fraction)
Briefly describe Standard dose
total plasma concentration within T.R, adverse effects w/ free fraction or no therp benefit to low free fract
T/F changes in active fractions may not occur secondarily to changes in plasma protein concentration
False
Describe ALB
majority of
major..
majority of plasma protein const.
major transporter of blood
T/F free fractions are influenced by other drugs
True
T/F measurement of free fractions shouldn’t be considered when drugs are highly bound/or have clinical signf inconsistences
False
Describe Drug Metabolism
how are all substances absorbed
All substances are absorbed from intestines and (excreted through rectum) enter hepatic portal
Describe the first pass effect in drug metabolism
drug is metabolized reduced effect before reaching circulation system
certain drugs have significant hepatic metabolism
Describe an inpaired liver
tam
reduced metabolism absorbtion/dosing adjustments theraputic active metabolite
T/F most drugs aren’t Xenobiotics
false, most drugs are
Describe Xenobiotics
EXOGENOUS substances able to enter biochem pathway ment for endogenous pathway
Whatre the two groups for Xenobiotics
Phase 1 reactive - reactive intermediates
Phase 2 - conjugate function groups to react sits in H20 sol production
T/F MFO is non specific, endo/exogeneous subst. to go through
true
Describe Drug elimination
free fractions subject to golm. filtration and renal secretion
Drugs not secreted are reabsorbed
T/F elimination rates are directly related to GFR
Decreased GFR results in Decreased Half life
True
T/F decrease in plasma drug [ ] is most often not a first order reaction
false it is mostly a first order process
Exponential rate of loss
T/F most drugs are not administered as a single bolus but on a scheduled basis
true
How many doses are typically needed before a steady-state is achieved
5-7 doses
Describe Pharmacodynamics
biochem/physiological effects of drugs/mean of their actions is described as relationship between drug [ ] at site of action and response
What is the most common mechanism of action
drug activates receptors at site of action
Describe Emax
EC50
max efficiency
50% max efficiency
Describe tolerance
constant exposure of receptors to drugs that leads to less of a response
What is the single most important factor in specimen collection
When is peak? (Oral/IV)
timing
Peak in oral is after 1 hr
Peak in IV is 90 min
T/F drug only appears after steady state is achieved
What is the specimen of choice
true
Serum is the specimen of choice (gel may interfere)
Describe Pharmacogenomics
effectivness?
science of studying variations and developing drug therapies to compensate for genetic drift impacting therapy regimens
Effectiveness depends on pt response
T/F responders to drugs have more benefit while non responders do not have a beneficial effect
true
What is the primary drug affecting gene metabolism, What does it encode for?
CYP450
Encodes for Cytochrome P450
Briefly Describe Digoxin
What kind of drug
treats?
inhibits?
peak?
elim?
Drugs that impact?
cardiactive drug
treats arrythmias
Inhibits NaK-ATPase
Peak 2-3 hrs
Elim through renal
Digibind (overdose)
biotin do not use at same time
Describe briefly Quiniaine
What kind of drug
natural from?
routes
peak
Cardioactive drug
natural from bark
Oral/GI
peak 2hrs
Briefly decribe Disopyramide
what kind of drug
substitute for?
peak?
elim?
binds to
Cardioactive drug
Substitute for Quiniaine
Peak 1-2 hr
renal elim
binds to serum/plasma prt
Briefly Describe Procanamide
What kind of drug
rapid in?
peak?
elim?
Cardioactive drug
oral rapid
peak 1 hr
renal/hepatic
Describe NAPA
Hepatic metabolizm of procanimide
Describe Aminoglycosides briefly
what type of drug
what kind of infections
inhibits?
incr
poor?
what kind of drug absorb
Abx
Gram Neg/Gram pos infections
inhibits bacteria synth
incr. bld [ ] can affect
POORLY ABSORBED IN GI
IV/IM
Describe Getamiein Briefly
what kind of drug
treats?
how many times a day
doses?
Abx
Treats GNR - life threatening
2-3x a day
can do high doses
Briefly describe Tobramycin
What kind of drug
treats
what kind of toxin
ABX
Treats GNR
Ototoxic/Nephrotoxic
Baseline with audiology testing
Decribe Amiracin
what kind of drug
infection
taken how
Abx
severe blood infection
orally
Describe Vancomycin
what kind of drug
Treats
Syndromes?
Poor
What kind of toxin
ABX
GPC/GNR
Redman syndrome
poor GI absorb
nephro/auto toxin
Briefly describe Anti epileptic drugs
whatis critical?
treat/supress seizures
TDM critical
Describe Primidone
what kind of drug
treats
converted by?
Gets to what quicker
Anti epileptic drug
grand mal seizures
conv. by liver met
gets to steady state quicker
Describe Phenorbital
what kind of drug
action is fast or slow?
Elim
What is measured
Anti-epileptic
slow acting oral
Elim w hepatic
only troughs measured
Describe Phenytonin/free phenytonin
treats what
dosing problems
bound/free
Common treat for seizures/short term prophy agent in brain injury
seizures in hyper/hypo dosing
total and free fraction (90% bound 10%free)
Describe Volproic acid (depakole)
what kind of drug
rapid?
bound?
what metabolism
Dysfunction?
Anti epileptic
oral-gi rapid
HIGHLY PRT BOUND
hept met
dysf 6 mos
Describe Carbamazepine
what kind of drug
effects?
Gabapentin
what kind of drug
binds to? in what kind of pts?
severe adverse effects/last resort/high variable/toxic
Gaba- seizures/pain management
binds to protein (pt w liver disease)
Describe Lithium
what kind of drug
rapid/slow?
binding?
phsychoactive drug
mood alt
oral rapid
doesnt bind to proteins
Describe Tricyclic antidepressents (TAD)
Clozapin
Olanzapine
depression/insom/loss of libido
Clo - schizophrenia refractory
TDM checks
Ola- schizophrenia/mania
Describe Cyclosporin
What diseases/dependent on/what type of blood
Tacroliaus
Potency
Sirolinus
Anti…
Cyclo - cyclic polypept - suppresses graft vs host/whole blood/temp depend
T -100x more potent
S - antifungal kidney transplant
Describe Anti neoplastics
what type of dose
drug?
M
treat cancers rapid met
delivered dose
METHOTREXATE
Describe Bronchodilators
Respiratory disorders/asthsma
people who cant use inhalers
THEOPHYLLINE
