THERAPEUTIC DRUG MONITORING AND CLINICAL TOXICOLOGY Flashcards
Clinical chemistry laboratory
– Provides information concerning the diagnosis and management of patients suspected to _______________
– Provides information in patients __________________
– Assessment of individuals _____________
have taken drug overdose
taking drugs for treatment of disease conditions
screened for drugs of abuse
Therapeutic Drug Monitoring
Involves the analysis, assessment and evaluation of ___________ in serum, plasma, or whole blood.
Purpose is to ensure the medication dose is __________ and not _____
circulating concentrations of drugs
at therapeutic range and not toxic.
TDM enables the assessment of the ______ and ______ of a particular medication in a variety of clinical settings.
efficacy and safety
The goal of TDM is to _______ therapeutic regimens for optimal patient benefit
individualize
Key points of therapeutic drug monitoring
Goal
-Ensure that a given drug dosage produces maximal ______ and Minimal ________
-Must have _______ at site of action that produces benefits
therapeutic benefit ; toxic adverse effects
an appropriate concentration
Key points of therapeutic drug monitoring
Standard dosages are derived from _______
Only the ______ fraction of drugs can interact with site of action, resulting in a biologic response
healthy population
free
THERAPEUTIC RANGE/ THERAPEUTIC WINDOW
The therapeutic range is the _____ of drug in plasma where the drug has been shown to be _____ without ________
concentration range
efficacious; causing toxic effects in most people.
TARGET CONCENTRATION AND THERAPEUTIC RANGE -Range introduces uncertainty into ___________ the desired dose
exactly how to prescribe
INDICATIONS FOR TDM
Drugs for which relationship between dose and plasma concentration is unpredictable, e.g _________
Drugs with a narrow therapeutic window:- will allow dosage alterations to produce optimal therapeutic effect or to avoid toxic effects. Ex: ____,_____ and _____
Drugs for which there is difficulty in measuring or interpreting the clinical evidence of therapeutic or toxic effects,e.g, Nausea & vomiting occur in both ______ toxicity & ______
Drug with poorly defined end point or difficult to clinically predict the response. Example: _______ drugs
Phenytoin
Lithium, phenytoin, and digoxin
digitalis; congestive heart failure
immunosuppressant
INDICATIONS FOR TDM
Drug interactions: When another drug alters the relationship between dose & plasma concentration e.g. plasma concentration of lithium is increased by _______
For diagnosis of suspected toxicity & determining drug abuse
To evaluate compliance of patient
Guiding withdrawal of therapy: _____,_____
thiazide
Antiepileptics, Cyclosporine.
DRUGS THAT ARE NOT SUITABLE FOR TDM
Drugs having (narrow or wide?) therapeutic index
Toxicity is not a realistic concern ( ____ )
Effects can be measured using laboratory tests (______)
Plasma concentration not predictably related to effects ( ______ )
Effect of the relationship remains undefined (________)
Wide; Penicillin
Anticoagulants
Anticoagulants
Antidepressants
The following are important considerations to ensure an optimum TDM service in any setting
-Measurement of ___________ taken at appropriate time after drug administration
-Knowledge of _______________________
-Knowledge of _________ like demographic data, clinical status, laboratory and other clinical investigations
-__________ after taking into consideration all of the above information and individualizing drug regimen according to the clinical needs of the patient.
patient’s serum or plasma drug concentration
pharmacological and pharmacokinetic profiles of the administered drugs
relevant patient’s profile
Interpretation of SDC
Pharmacokinetics’ Process assists in establishing or modifying a dosage regimen
T/F
T
Most drugs given as a single bolus or mass
T/F
F
Most drugs given on a scheduled basis not as a single bolus or mass
Goal of dosage regimens
Achieve troughs in _______ and peaks that _____
therapeutic range
are non-toxic
_______, which gives a measure of the unbound drug concentration, may be a useful alternative when blood samples are difficult to collect.
Saliva
Avoid serum-separator tubes because these may _______ due to the ________
lower drug concentrations
adsorption of drug into the matrix.
Storage of samples: __________ type tubes are acceptable for most assays
Plastic cryovial
GUIDELINES TO SPECIMEN COLLECTION
1) Blood specimens for drug monitoring can be taken at ______ times - during the _________ therapeutic concentration (‘peak’ level), or its _____ (‘trough’ level).
Occasionally called _____ levels, trough levels show _______ levels; whereas peak levels show ____
two different
drug ́s highest ; lowest
residual; sufficient therapeutic
toxicity
Peak and trough levels should fall within the therapeutic range.
T/F
T
For chronically administered oral medications the peak levels usually occur _____ after the dose and the trough serum concentration ________.
______ is one exception.
1-2 hours
shortly after the dose is administered
Digoxin
The serum level to determine peak activity should be drawn after the serum digoxin __________ i.e., ______ after the oral dose.
Drawing the trough level at _______ is usually sufficiently accurate.
has had time to equilibrate with the tissue
6-10 hours
the time the dose is given
Intravenous medications should be given time to equilibrate before the peak level is drawn.
T/F
T
Intravenous medications should be sampled _____ after administration.
For example, the peak serum level of Gentamicin should be drawn _________ after infusion of the drug ends and not ______________
1⁄2-1 hour
thirty minutes
immediately after the infusion.
