Difference between revisions of "Anticonvulsant levels and reloading"

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| [[Carbamazepine]] (Tegretol)
 
| [[Carbamazepine]] (Tegretol)
|8 mg/kg suspension in single oral load  
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|8mg/kg suspension in single oral load  
 
|NA
 
|NA
 
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| [[Phenytoin]] (Dilantin)  
 
| [[Phenytoin]] (Dilantin)  
 
|20 mg/kg divided in maximum doses of 400 mg every 2 hours
 
|20 mg/kg divided in maximum doses of 400 mg every 2 hours
|18 mg/kg (max rate of 50 mg/min)  
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|18mg/kg (max rate of 50 mg/min)  
 
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|[[Fosphenytoin]] (Cerebyx)  
 
|[[Fosphenytoin]] (Cerebyx)  

Revision as of 22:12, 18 July 2016

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) 8mg/kg suspension in single oral load NA
Gabapentin (Neurontin) 900 mg/day oral (300 mg tid) for 3 days NA
Lamotrigine (Lamictal) 6.5mg/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 NA
Levetiracetam (Keppra) 1,500 mg oral load Up to 60 mg/kg (rapid loading)
Phenytoin (Dilantin) 20 mg/kg divided in maximum doses of 400 mg every 2 hours 18mg/kg (max rate of 50 mg/min)
Fosphenytoin (Cerebyx) NA 18 PE/kg IV (max rate of 150 PE/min)
Valproate (Depacon) NA Up to 30 mg/kg IV (max rate of 10 mg/kg/min)

Reloading

  • 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

References

  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.