Anticonvulsant levels and reloading: Difference between revisions

Revision as of 07:07, 28 March 2011

Dose (mg) = weight^ (kg) X volume of distribution X [desired level - current level (mcg/mL)]

^Ideal body weight

If patient's optimal levels known = desired level
If not, target upper end of therapeutic range:
1. Phenytoin = 20 mcg/mL
2. Phenobarbital = 40 mcg/mL
3. Valproate = 100 mcg/mL

Iv load can be performed with phenobarbital, phenytoin/fosphenytoin, valproate, or levetiracetam.
Oral loading often limited by neurotoxic adverse effects (n/v) , but can spread dose out over a day or more if necessary.
1. (e.g. phenytoin PO 400 mg Q4 to reach the final dosage)

DONALDSON 3/08 (from emedicine; Treiman 1997; Bourgeois, 1996)

Authors:

@@ Line 1: / Line 1: @@
-==Background==
+== Background ==
-===DOSE===
+=== Dose ===
 Dose (mg) = weight^ (kg) X volume of distribution X [desired level - current level (mcg/mL)]
@@ Line 6: / Line 7: @@
 ^Ideal body weight
-===VOLUME OF DISTRIBUTIONS===
+=== Volume of Distribution ===
-Phenytoin (dilantin) 0.8
-Carbamazepine (tegretol) 0.8
-Phenobarbital 0.6
+{| style="width: 500px" border="1" cellpadding="1" cellspacing="1"
+|-
+| '''Agent<br/>'''
+| '''Volume of Distribution<br/>'''
+|-
+| Phenytoin (dilantin)
+| 0.8
+|-
+| Carbamazepine (tegretol)
+| 0.8
+|-
+| Phenobarbital
+| 0.6
+|-
+| Valproate (depakote)
+| 0.2
+|}
-Valproate (depakote) 0.2
+=== Desired Level ===
-===DESIRED LEVEL===
 #If patient's optimal levels known = desired level
 #If not, target upper end of therapeutic range: