Phenobarb -maintenance therapy.

[Sutirtha Roy]

Dear Stefan,

How are you? This is Roy again. I am putting the question in the open forum for discussion as you suggested regarding the use of adequate [?better] maintenance therapy for PHENOBARBITAL. Which I think is very essential for the use of this classical anti-convulsanat.

I would like to know what recommendations will you [or our other forum members]suggest to follow regarding the management of neonatal seizures [chiefly Post asphyxial] if quality EEG facilities are not available?

And how to withdraw the maintenance PHENOBARBITAL? My specific question is:


I.How long should we continue the medication and how to omit in a set up with limited resources and

II.Considering the long half life in the early neonatal period what regimen do you follow as the PHENOBARB maintenance Therapy once daily [OD]or twice [BID]?

[** I rose the the question because as far the current recomendations of the Clinacal Paediatric Neurology by Fenichel andNeonatal Formulary [The Nothern Neonatal Pharmacopoeia, BMJ] the plama half life in early neonatal period is so long [48-up to 200 Hrs] the maintenance therapy once a is perfectly all right.
As as the drug is largely metabolized by liver considering the initial immaturity and inability in the early conjugation process should also come in to account.Therapeutic level in the Neonatal Period is 20-40 mg/l [1 mg/l=4.42 micro mole/l].
This is higher than the range generally quoted for use in later childhood.]


Looking for the reply.

Warm Regards, Roy.

[Stefan Johansson]

Dear Roy,
the first issue you raise, how to deal with seizures with EEG facility, I would suggest that you mainly have the option to diagnose seizures from the clinical picture, despite the discrepancy between "clinical" and "EEG-confirmed" seizures.

Our strategy for maintenance therapy depends: if there are isolated seizures shortly after birth that responds easily with loading dose of phenobarb (and do not relapse) we would not use maintenance therapy. In more complicated cases we generally keep phenobarb for maintenance treatment. Given freedom of seizures, we do not increase the dose as the child grows, and stop treatment after 3-6 months.

Our maintenance dose if 3-5 mg phenobarb/kg/day, and give phenobarb twice daily. You have a good point about the long half-life, from a pharmacokinetic point of view I guess once daily would be enough. Would be interesting to hear how other members do.

Best wishes, Stefan

[hehady]

We give 5 mg/kg/d divided into two doses. In some cases we give up to 8 mg/kg/d.

[mr_raider]

Have you considered acquiring aEEG monitoring equipment? It is cheaper than full EEG equipment, and neonatologits/pediatricians can be trained to read it. Seizure detection capability is inferior however to conventional EEG.

As for duration of treatment for asphyxia, there is no consensus. Most people agree that once the initial insult has resolved, most babies do not need months of maintenance therapy.

[Ruth]

We use a loading dose of 20mg/kg IV repeated to a cumulative max of 100mg/kg to stop the sezures. Maintenance dose is 3-4mg/kg daily (usually nocte)
We usually stop it prior to discharge and monitor that the seizures do not recur.
If the seizures persist despite phenobarb consider a midazolam infusion of 50-100mcg/kg/hr