Anticonvulsant levels and reloading: Difference between revisions
(Created page with "==Background== DOSE Dose (mg) = weight* (kg) X volume of distribution X [desired level - current level (mcg/mL)] *Ideal body weight ==Diagnosis== VOLUME OF DISTRIBUT...") |
Elcatracho (talk | contribs) |
||
| (57 intermediate revisions by 7 users not shown) | |||
| Line 1: | Line 1: | ||
==Background== | ==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<ref name="ACEP">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> | |||
==Initial Loading<ref name="ACEP"></ref>== | |||
{|class="wikitable" | |||
|'''[[Anticonvulsant]] (brand name)''' | |||
|'''PO Loading Dose''' | |||
|'''IV Loading Dose''' | |||
|- | |||
| [[Carbamazepine]] (Tegretol) | |||
|8mg/kg suspension in single oral load | |||
|NA | |||
|- | |||
| [[Gabapentin]] (Neurontin) | |||
|900mg/day oral (300mg 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) | |||
|1,500mg oral load | |||
|1,000-1,500 mg IV | |||
|- | |||
| [[Phenytoin]] (Dilantin) | |||
|20mg/kg divided in maximum doses of 400mg every 2 hours | |||
|18mg/kg (max rate of 50mg/min) | |||
|- | |||
|[[Fosphenytoin]] (Cerebyx) | |||
|NA | |||
|18 PE/kg IV (max rate of 150 PE/min) | |||
|- | |||
| [[Valproate]] (Depacon) | |||
|NA | |||
|Up to 30mg/kg IV (max rate of 10mg/kg/min) | |||
|} | |||
==Reloading== | |||
*'''Dose (mg) = [[ideal body weight estimation|ideal body weight]] (kg) X Vd X [desired level - current level (mcg/mL)]''' | |||
===Volume of Distribution=== | |||
{| class="wikitable" | |||
|- | |||
| '''Agent''' | |||
| '''Volume of Distribution''' | |||
| '''Desired Level''' | |||
|- | |||
| Phenytoin (dilantin) | |||
| 0.8 | |||
| 20 mcg/mL | |||
|- | |||
| Carbamazepine (tegretol) | |||
Phenytoin (dilantin) 0.8 | | 0.8 | ||
| 12 mcg/mL | |||
Carbamazepine (tegretol) 0.8 | |- | ||
| Phenobarbital | |||
Phenobarbital 0.6 | | 0.6 | ||
| 40 mcg/mL | |||
Valproate (depakote) 0.2 | |- | ||
| Valproate (depakote) | |||
| 0.2 | |||
| 100 mcg/mL | |||
|} | |||
==See Also== | ==See Also== | ||
*[[Seizure]] | |||
*[[Seizure (peds)]] | |||
*[[Seizure with known seizure disorder]] | |||
*[[Anticonvulsants]] | |||
==References== | |||
<references/> | |||
[[Category:Pharmacology]] | |||
[[Category:Neurology]] | |||
[[Category: | |||
Latest revision as of 03:59, 8 March 2021
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) | 900mg/day oral (300mg 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) | 1,500mg oral load | 1,000-1,500 mg IV |
| Phenytoin (Dilantin) | 20mg/kg divided in maximum doses of 400mg every 2 hours | 18mg/kg (max rate of 50mg/min) |
| Fosphenytoin (Cerebyx) | NA | 18 PE/kg IV (max rate of 150 PE/min) |
| Valproate (Depacon) | NA | Up to 30mg/kg IV (max rate of 10mg/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 |