Difference between revisions of "Anticonvulsant levels and reloading"

(Levels)
(Initial Loading)
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{|class="wikitable"
 
{|class="wikitable"
 
|'''Anticonvulsant (brand name)'''
 
|'''Anticonvulsant (brand name)'''
|'''Loading Dose and Route of Administration'''
+
|'''PO Loading Dose'''
 +
|'''IV Loading Dose'''
 
|-
 
|-
| [[Carbamazepine]] (Tegretol)||PO: 8 mg/kg suspension in single oral load  
+
| [[Carbamazepine]] (Tegretol)
IV: not available  
+
|PO: 8 mg/kg suspension in single oral load  
 +
|IV: not available  
 
|-
 
|-
| [[Gabapentin]] (Neurontin) ||PO: 900 mg/day oral (300 mg tid) for 3 days
+
| [[Gabapentin]] (Neurontin)  
IV: not available  
+
|PO: 900 mg/day oral (300 mg tid) for 3 days
 +
|IV: not available  
 
|-
 
|-
| [[Lacosamide]] (Vimpat) ||PO: dosages not studied  
+
| [[Lacosamide]] (Vimpat)  
IV: not studied  
+
|PO: dosages not studied  
 +
|IV: not studied  
 
|-
 
|-
| [[Lamotrigine]] (Lamictal) ||PO: 6.5 mg/kg single oral load if on lamotrigine for >6 mo without a history of rash or intolerance in the past and only off lamotrigine for <5 days
+
| [[Lamotrigine]] (Lamictal)  
IV: not available  
+
|PO: 6.5 mg/kg single oral load if on lamotrigine for >6 mo without a history of rash or intolerance in the past and only off lamotrigine for <5 days
 +
|IV: not available  
 
|-
 
|-
| [[Levetiracetam]] (Keppra) ||PO: 1,500 mg oral load
+
| [[Levetiracetam]] (Keppra)  
IV: rapid IV loading safe and well tolerated in doses up to 60 mg/kg  
+
|PO: 1,500 mg oral load
 +
|IV: rapid IV loading safe and well tolerated in doses up to 60 mg/kg  
 
|-
 
|-
| [[Phenytoin]] (Dilantin) ||PO: 20 mg/kg divided in maximum doses of 400 mg every 2 hours
+
| [[Phenytoin]] (Dilantin)  
IV: 18 mg/kg at maximum rate of 50 mg/min  
+
|PO: 20 mg/kg divided in maximum doses of 400 mg every 2 hours
 +
|IV: 18 mg/kg at maximum rate of 50 mg/min  
 
|-
 
|-
| [[Fosphenytoin]] (Cerebyx) ||PO:  
+
| [[Fosphenytoin]] (Cerebyx) |
IV: 18 PE/kg IV at maximum rate of 150 PE/min
+
|PO:  
IM: administration possible
+
|IV: 18 PE/kg IV at maximum rate of 150 PE/min
 
|-
 
|-
| [[Valproate]] (Depacon) ||PO:
+
| [[Valproate]] (Depacon)  
IV: Up to 30 mg/kg IV at max rate of 10 mg/kg/min
+
|PO:
 +
|IV: Up to 30 mg/kg IV at max rate of 10 mg/kg/min
 
|}
 
|}
  

Revision as of 13:53, 25 August 2015

Background

  • IV load can be performed with phenobarbital, phenytoin, valproate, levetiracetam
  • Oral loading can be spread over day or more to avoid GI upset
  • May use IV vs PO reload at physican discretion[1]

Initial Loading[1]

Anticonvulsant (brand name) PO Loading Dose IV Loading Dose
Carbamazepine (Tegretol) PO: 8 mg/kg suspension in single oral load IV: not available
Gabapentin (Neurontin) PO: 900 mg/day oral (300 mg tid) for 3 days IV: not available
Lacosamide (Vimpat) PO: dosages not studied IV: not studied
Lamotrigine (Lamictal) PO: 6.5 mg/kg single oral load if on lamotrigine for >6 mo without a history of rash or intolerance in the past and only off lamotrigine for <5 days IV: not available
Levetiracetam (Keppra) PO: 1,500 mg oral load IV: rapid IV loading safe and well tolerated in doses up to 60 mg/kg
Phenytoin (Dilantin) PO: 20 mg/kg divided in maximum doses of 400 mg every 2 hours IV: 18 mg/kg at maximum rate of 50 mg/min
Fosphenytoin (Cerebyx) | PO: IV: 18 PE/kg IV at maximum rate of 150 PE/min
Valproate (Depacon) PO: IV: Up to 30 mg/kg IV at max rate of 10 mg/kg/min

Reloading

Dose

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

Volume of Distribution

Agent Volume of Distribution Desired Level
Phenytoin (dilantin) 0.8 20 mcg/mL
Carbamazepine (tegretol) 0.8 12 mcg/mL
Phenobarbital 0.6 40 mcg/mL
Valproate (depakote) 0.2 100 mcg/mL

See Also

Source

  1. 1.0 1.1 Seizures ACEP Policy committee . Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Seizures. Ann Emerg Med. 2014;63(4):437–447.e15. doi:10.1016/j.annemergmed.2014.01.018.