Anticonvulsant levels and reloading: Difference between revisions

Revision as of 09:40, 4 October 2011

Dose (mg) = ideal body weight (kg) X Vd X [desired level - current level (mcg/mL)]

Pt's optimal level = = desired level
1. If optimal level unknown target upper end of therapeutic range:
  1. Phenytoin = 20 mcg/mL
  2. Valproate = 100 mcg/mL
  3. Phenobarbital = 40 mcg/mL

IV load can be performed with phenobarbital, phenytoin, valproate, levetiracetam
Oral loading can be spread over day or more to avoid GI upset
1. (e.g. phenytoin PO 400 mg Q4 to reach the final dosage)

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

Authors:

@@ Line 2: / Line 2: @@
 === Dose ===
+Dose (mg) = ideal body weight (kg) X Vd X [desired level - current level (mcg/mL)]
-Dose (mg) = weight^ (kg) X volume of distribution X [desired level - current level (mcg/mL)]
-^Ideal body weight
 === Volume of Distribution ===
@@ Line 28: / Line 25: @@
 === Desired Level ===
+#Pt's optimal level = = desired level
-#If patient's optimal levels known = desired level
+##If optimal level unknown target upper end of therapeutic range:
-#If not, target upper end of therapeutic range:
+###Phenytoin = 20 mcg/mL
-##Phenytoin = 20 mcg/mL
+###Valproate = 100 mcg/mL
-##Phenobarbital = 40 mcg/mL
+###Phenobarbital = 40 mcg/mL
-##Valproate = 100 mcg/mL
 ==Treatment==
-#Iv load can be performed with phenobarbital, phenytoin/fosphenytoin, valproate, or levetiracetam.
+#IV load can be performed with phenobarbital, phenytoin, valproate, levetiracetam
-#Oral loading often limited by neurotoxic adverse effects (n/v) , but can spread dose out over a day or more if necessary.
+#Oral loading can be spread over day or more to avoid GI upset
 ##(e.g. phenytoin PO 400 mg Q4 to reach the final dosage)