Guidelines for Intravenous Phenytoin Preparation
Preparation
compatibile in 0.9% normal saline and lacted ringers solution (incompatibile in dextrose)
store at room temperature - will crystalize out when refrigerated
dilute phenytoin in normal saline to final concentration between 1-10mg/ml
use 0.22 micron filter with phenytoin IV to prevent any crystals from getting into IV line
use shortly after diluting phenytoin solution, and discard unused solution after 4 hours
check IV bag periodically for any precipitate formulation
flush IV line with normal saline before and after phenytoin dose
	Dilution Guidelines
	Phenytoin Dose			Mininum Volume (Peripheral Line)			Suggested Volume (Central Line)
	600-1000mg			100 or 250mg 0.9% normal saline			100ml 0.9% normal saline
	301-600mg			100ml 0.9% normal saline			100ml 0.9% normal saline
	101-300mg			50ml 0.9% normal saline			50ml 0.9% normal saline
	100mg or less			25ml 0.9% normal saline			25ml 0.9% normal saline
Rate						Monitor
maximum rate in healthy adults: 50mg/min						EKG, HR, and BP at 60 second intervals for first 5 minutes, and every 5 minutes thereafter (up to 15-30 minutes after infusion completed)
in elderly, patients with cardiotoxicity risk factors, hypotensive patients, or patients with infusion associated pain: 25mg/min
						watch for cardiac arrhythmias, hypotension, bradycardia, and CNS depression
Managing Adverse Reactions
if hypotension or bradycardia occurs - discontinue infusion and restart at half the initial rate when vital signs return to pre-infusion values						also monitor for: albumin, hepatic function, and serum phenytoin
						normal serum phenytoin: 10-20mcg/ml (free phenytoin 1-2mcg/ml)
						need to adjust for low albumin (because phenytoin binds to albumin)
if patient complains of pain or burning - decrease infusion rate or further dilute infusion (min. 1mg/ml)
						use formula for corrected phenytoin: corrected level = observed level / 0.25 X albumin + 0.1
if extravasation occurs - elevate patient's limb, use a cold pack, and if necessary use Wydase (Hyaluronidase):
						need to adjust phenytoin rates in patients with severe liver impairment/cirrhosis
add 1ml of normal saline to 150 units vial to make 150 unit/ml concentration, and administer 0.2ml sc/im to the site at the leading edge
						Limitations
						currently, phenytoin IVPB is limited to the Emergency Dept. only
						services are expected to be expanded to include ICU, CCU, and RICU
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