Phenytoin - davis Flashcards
Pheyntoin salt fator of 1
tablets and suspension
phenytoin salt factor of 0.92
capsules and iv
iv max infuse rate
50mg/min
po max ingestion rate
400 mg po every 2 hours
protein bound?
yes to albumin
level of protein-bound
10- free
90 - bound
therapeutic range of phenytoin
40-80 mewmol/l
10-20 mg/l
when do we conside rhypoalbuminemia?
when less then 3.2 g/dl
dl to ml
1 dL= 100mL
what should we be careful about co-adminstering it with?
antacids could decrease absorption
what is it distribution of phenytoin like
widely distributed all over
lab values in phenytoin acid or salt?
acid
conversion fro mew mol/l to mg/l
mew mol/l = 3.96 X mg/l
what disease states should we be aware of for altering phenytoin levels
renal failure, hypoalbuminemia, liver disease
what drugs can alter valproate levels?
valproate acid or aspirin
main points to know about valproate acid use
therpautic level - 50 mg/L to 100 mg/L
at 70mg /l can decrease serum phenytoin levels by 40%
causing increased free fraction and increased elimination
what populations can u expect hypoalbunmeia in?
pregnancy or gernatics
ESRD details on what it does to phenytoin
less albumin and accumulation of p-hPPh( metabolite that diplaces phenytoin)
how is pheyntoin metabolixed
95% metabolized by CYP 450
via hydroxylation and glucuronadation
how is heyntoin eleiminated
5% unchange in urine
cl refelct amount/time not volume over time
how long till css is achived
allow one week
what is the Css target
15mg/L
Vmax
7mg/kg/day
km
4 mg/L
