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use antipyretic agents was likely to (inappropriately) increase parental anxiety and ‘fever
phobia’.

Intermittent prophylactic anticonvulsants. Intermittent prophylactic oral or rectal diazepam
reduce the number of febrile recurrences. The guidelines published by the MRC/BPA Joint
Working Group61 acknowledged that rectal diazepam could be effective in preventing
convulsions when given at the onset of fever and a large oral dose of phenobarbitone may
give an effective blood concentration in 90 minutes, but did not recommend the use of either
drug in this way because both caused drowsiness.

Since then a randomised placebo-controlled trial in America concluded that oral diazepam,
given only when fever is present, is safe and reduces the risk of recurrent febrile seizures76.
On the basis of the results the authors recommended starting oral diazepam at the first sign
of illness. Treatment with diazepam should then continue if the child becomes febrile, and
should stop after a day or two if no fever develops. In the paper the authors stated that
diazepam has no serious side effects, but 38.6% of the 153 children who received at least one
dose of diazepam had what the authors termed moderate side effects. These included ataxia
(30.0%), lethargy (28.8%) and irritability (24.2%).

In their editorial review Camfield et al75 pointed out that the only placebo-controlled trials of
intermittent administration have been with orally administered diazepam. A meticulous study
by Uhari77 had shown no benefit in preventing recurrence, even when the oral diazepam was
combined with acetaminophen. Autret et al78 also found no benefit from diazepam  the
authors concluded that the failure was due to the difficulties of early identification of the
fever and the logistics of administering medication intermittently to children with multiple
carers rather than to the ineffectiveness of the drug.

Continuous prophylactic anticonvulsants

‘The vogue for long-term anticonvulsant prophylaxis against febrile convulsions seen in the
1970s and early 1980s has passed’, according to the RCP/BPA Joint Working Group61.

What is the basis for making the decision about giving medication to prevent recurrences?
Aicardi17 reviewed the research into the continuous oral use of drugs to prevent recurrence
of febrile convulsions. This can be summarised as follows:

 Phenobarbitone at a dose of 45 mg/kg/day reduces the number of febrile recurrences;
phenobarbitone has a number of behavioural side effects, intolerable behaviour being
reported in up to 21% of children taking the drug.

 Sodium valproate has also been shown to prevent febrile recurrences.
 Experience with other continuous anticonvulsants is limited and unsatisfactory.

Despite the evidence that drugs can reduce recurrences there are good arguments that
prophylactic medication is rarely indicated. In the American NCPP cohort9,10 there were 1706
children with febrile convulsions who were assessed at seven years of age. Not one child had
a brief initial febrile convulsion that was followed by a prolonged recurrence and then by
epilepsy. This undermines the argument that prevention of febrile recurrences will prevent
‘brain damage’ and thus reduce the risk of developing epilepsy.

In the NCPP 90% of the children who were epileptic after febrile convulsions by seven years
had never had a febrile convulsion that lasted as long as 30 minutes. In the minority who
became epileptic after having had a lengthy seizure, this was the first seizure of their lives.
Similar conclusions have been reached as a result of the more recent population-based
CHES14.