Difference between revisions of "Anticonvulsant levels and reloading"

(/* LoadingSeizures 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...)
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*IV load can be performed with phenobarbital, phenytoin, valproate, levetiracetam
 
*IV load can be performed with phenobarbital, phenytoin, valproate, levetiracetam
 
*Oral loading can be spread over day or more to avoid GI upset
 
*Oral loading can be spread over day or more to avoid GI upset
 
=== Dose ===
 
Dose (mg) = ideal body weight (kg) X Vd X [desired level - current level (mcg/mL)]
 
 
=== Volume of Distribution ===
 
 
{| 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
 
|}
 
 
=== Desired Level ===
 
*Pt's optimal level = desired level
 
**If optimal level unknown target upper end of therapeutic range:
 
***Phenytoin = 20 mcg/mL
 
***Valproate = 100 mcg/mL
 
***Phenobarbital = 40 mcg/mL
 
  
 
==Loading<ref>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.</ref>==
 
==Loading<ref>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.</ref>==
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| [[Valproate]] (Depacon) ||Up to 30 mg/kg IV at max rate of 10 mg/kg/min IV  
 
| [[Valproate]] (Depacon) ||Up to 30 mg/kg IV at max rate of 10 mg/kg/min IV  
 
|}
 
|}
 +
 +
==Reloading==
 +
=== Dose ===
 +
Dose (mg) = ideal body weight (kg) X Vd X [desired level - current level (mcg/mL)]
 +
 +
=== Volume of Distribution ===
 +
 +
{| 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
 +
|}
 +
 +
=== Desired Level ===
 +
*Pt's optimal level = desired level
 +
**If optimal level unknown target upper end of therapeutic range:
 +
***Phenytoin = 20 mcg/mL
 +
***Valproate = 100 mcg/mL
 +
***Phenobarbital = 40 mcg/mL
  
 
==See Also==
 
==See Also==
 +
*[[Seizure]]
 
*[[Seizure (Peds)]]
 
*[[Seizure (Peds)]]
 
*[[Febrile Seizure]]
 
*[[Febrile Seizure]]

Revision as of 17:06, 21 April 2014

Background

  • IV load can be performed with phenobarbital, phenytoin, valproate, levetiracetam
  • Oral loading can be spread over day or more to avoid GI upset

Loading[1]

Drug (with brand name) Loading Dose and Route of Administration
Carbamazepine (Tegretol) 8 mg/kg oral suspension;

single oral load; IV not available

Gabapentin (Neurontin) 900 mg/day oral (300 mg tid) for 3 days;

IV not available

Lacosamide (Vimpat) Oral and IV formulations available and safe;

loading dosages not studied

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; IV not available

Levetiracetam (Keppra) 1,500 mg oral load;

rapid IV loading safe and well tolerated in doses up to 60 mg/kg

Phenytoin (Dilantin) 20 mg/kg divided in maximum doses of 400 mg every 2 h orally;

or 18 mg/kg IV at maximum rate of 50 mg/min

Fosphenytoin (Cerebyx) 18 PE/kg IV at maximum rate of 150 PE/min;

IM administration possible

Valproate (Depacon) Up to 30 mg/kg IV at max rate of 10 mg/kg/min IV

Reloading

Dose

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

Volume of Distribution

Agent
Volume of Distribution
Phenytoin (dilantin) 0.8
Carbamazepine (tegretol) 0.8
Phenobarbital 0.6
Valproate (depakote) 0.2

Desired Level

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

See Also

Source

  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.