Anticonvulsant levels and reloading

Revision as of 14:04, 25 August 2015 by Rossdonaldson1 (talk | contribs) (Initial Loading)

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) 8 mg/kg suspension in single oral load NA
Gabapentin (Neurontin) 900 mg/day oral (300 mg tid) for 3 days NA
Lamotrigine (Lamictal) 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 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 18 mg/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

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.