1 Flashcards
absorption
the process of a substance entering the systemic circulation
distribution
the dispersion of a substance throughout fluids and tissues of the body
metabolism (liver)
the transformation of parent compounds into daughter compounds–>biotransformation–> more polar –> to activate them
excretion (renal)
the removal of the substance from the body
excretion sites
renal/kidney
metabolism sites
the liver
distribution sites
vascular space (blood/plasma) to extravascular space (fat, muscles, interstitial space)
absorption site
depends on the mother fucking route of administration
a loading dose
a higher dose than required to compensation for the slow rater of absorption, low plasma concentration
[concentration]
mass/volume
mass
amount of drug, mg
blood volume
5L
plasma volume
blood volume-cell=2.5L
1cc (cubic centimeters)
1cc=1ml
a 10mg of drug X is 100% absorbed, what is the plasma drug concentration
10mg/2.5L
bolus
given all at once
serum
plasma -clotting factors
bioavailability
the fraction of the administsered dose that reaches the systemic circulation
AUC route/AUC iv
area under the curve
proportional to the amount of drug absorbed
if the oral bioavailability of a drug id 50%. if theIV dose is 50 mg what should the oral does be?
100mg
50ml/2.5L=0.5*(X/2.5L)
or
Mass (plasma mass)= Mass (adminstered) * bioavailability
volume of distribution, Vd
total mass absorbed (mass adminstered* bioabailability)/plasma concentration
what affects volume of distribution
high molecular weight, stay in plasma
binding to plasma protein decreases Vd
hydrophilic, low Vd 9staysin the plasma)
lipophillic. high Vd
where does metabolism occur?
in dat liver, smooth endoplasmic reticulium (the rough is used in protein synthesis)
first pass metabolism
goes through the portal vein, metabolised before it reaches the systemic circulation. Oral and rectal
phase 1 metabolism uses what
CYP450, alcohol dehydrogenase
Phase 2 metabolism uses what
conjugation reactions
glucuronidation
sulfation
acetylation
