Kinetics 14.5 - 16 Flashcards
Fraction or percentage of the drug removed from the perfusing blood during passage through the organ
EXTRACTION RATIO
Measure of the elimination of the drug by that organ
EXTRACTION RATIO
EXTRACTION RATIO
T/F: Drugs with high hepatic extraction ratio have large
1st-pass effect
True
EXTRACTION RATIO
T/F; One of the highest extraction would actually be your hepatic extraction
True
EXTRACTION RATIO
Notice that all the administered drug passes
through the portal circulation and is immediately acted upon by the (liver/Kidney)
Liver
EXTRACTION RATIO
T/F: Although there are also some drugs that need to
pass through the liver to be activated but most are
inactivated and are prepared to be excreted
True
EXTRACTION RATIO
There is a renal clearance dumping them out into the urine either through the process of _______ or to ________
filtration; tubular secretion
Drugs are eliminated unchanged or as metabolites
EXCRETION
EXCRETION
(Polar/Non Polar) compounds are more efficiently eliminated
Polar
EXCRETION
most important organ
Kidneys
When will we take the peak concentration?
For IV, we said around 30 minutes after IV administration
2-3 hours for oral administration
When it
is already fully absorbed or distributed
: What happens when the peak concentration is
above the minimum toxic?
For example, at 18 units mg/L meaning its
already a toxic concentration of the plasma
concentration. How will you act and adjust the dose?
You lower down the dose
Let’s say you give 10 mg/mL yung
concentration, since your peak is outside
the therapeutic window , you will make it 5
or 8 mg/mL
What happens when your trough concentration would fall below the minimum effective concentration?
You increase the dose; If you increase the dose, you will increase the plasma concentration
It’s possible that it won’t breach; however,
since you increased the dose, the rate of
eliminated becomes faster so that at the
end of your dosing interval it will dip down
below the effective concentration. What you need to do is shorten the dosage interval or increase the frequency of
dosing . If that was every 8 hours, you need to give
the next dose at 6 hours, so that it won’t go
down
Drug used for COPD and asthma
Theophylline
Is this the reason why yung iniinom na gamot
need i-take every specific hours?
Yes, usually therapeutic drug monitoring
would be just used for drugs with a narrow
therapeutic window.
However, for drugs with wide therapeutic window and high therapeutic index, there’s no need to
measure the plasma concentration because the toxic level is distant from the therapeutic level
