For the original review, two review authors independently applied predefined criteria to select trials for inclusion and extracted the predefined relevant data, recording methods for randomisation, blinding, and exclusions. For the 2016 update, a third review author checked all original inclusions, data analyses, and updated the search. For the 2020 update, one review author updated the search and performed the data analysis following a peer-review process with the original review authors. We assessed seizure recurrence at 6, 12, 18, 24, 36, 48 months, and where data were available at age 5 to 6 years along with recorded adverse effects. We evaluated the presence of publication bias using funnel plots.
MAIN RESULTS: We included 42 articles describing 32 randomised trials, with 4431 randomised participants used in the analysis of this review. We analysed 15 interventions of continuous or intermittent prophylaxis and their control treatments. Methodological quality was moderate to poor in most studies. We found no significant benefit for intermittent
phenobarbital,
phenytoin,
valproate,
pyridoxine,
ibuprofen, or
zinc sulfate versus placebo or no treatment; nor for
diclofenac versus placebo followed by
ibuprofen,
paracetamol, or placebo; nor for continuous
phenobarbital versus
diazepam, intermittent rectal
diazepam versus intermittent
valproate, or oral
diazepam versus
clobazam. There was a significant reduction of recurrent
febrile seizures with intermittent
diazepam versus placebo or no treatment at six months (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.48 to 0.85; 6 studies, 1151 participants; moderate-certainty evidence), 12 months (RR 0.69, 95% CI 0.56 to 0.84; 8 studies, 1416 participants; moderate-certainty evidence), 18 months (RR 0.37, 95% CI 0.23 to 0.60; 1 study, 289 participants; low-certainty evidence), 24 months (RR 0.73, 95% CI 0.56 to 0.95; 4 studies, 739 participants; high-certainty evidence), 36 months (RR 0.58, 95% CI 0.40 to 0.85; 1 study, 139 participants; low-certainty evidence), 48 months (RR 0.36, 95% CI 0.15 to 0.89; 1 study, 110 participants; moderate-certainty evidence), with no benefit at 60 to 72 months (RR 0.08, 95% CI 0.00 to 1.31; 1 study, 60 participants; very low-certainty evidence).
Phenobarbital versus placebo or no treatment reduced
seizures at six months (RR 0.59, 95% CI 0.42 to 0.83; 6 studies, 833 participants; moderate-certainty evidence), 12 months (RR 0.54, 95% CI 0.42 to 0.70; 7 studies, 807 participants; low-certainty evidence), and 24 months (RR 0.69, 95% CI 0.53 to 0.89; 3 studies, 533 participants; moderate-certainty evidence), but not at 18 months (RR 0.77, 95% CI 0.56 to 1.05; 2 studies, 264 participants) or 60 to 72 months follow-up (RR 1.50, 95% CI 0.61 to 3.69; 1 study, 60 participants; very low-certainty evidence). Intermittent
clobazam compared to placebo at six months resulted in a RR of 0.36 (95% CI 0.20 to 0.64; 1 study, 60 participants; low-certainty evidence), an effect found against an extremely high (83.3%) recurrence rate in the controls, a result that needs replication. When compared to intermittent
diazepam, intermittent oral
melatonin did not significantly reduce
seizures at six months (RR 0.45, 95% CI 0.18 to 1.15; 1 study, 60 participants; very-low certainty evidence). When compared to placebo, intermittent oral
levetiracetam significantly reduced recurrent
seizures at 12 months (RR 0.27, 95% CI 0.15 to 0.52; 1 study, 115 participants; very low-certainty evidence). The recording of adverse effects was variable. Two studies reported lower comprehension scores in
phenobarbital-treated children. Adverse effects were recorded in up to 30% of children in the
phenobarbital-treated groups and 36% in
benzodiazepine-treated groups. We found evidence of publication bias in the meta-analyses of comparisons for
phenobarbital versus placebo (seven studies) at 12 months but not at six months (six studies); and
valproate versus placebo (four studies) at 12 months. There were too few studies to identify publication bias for the other comparisons. The methodological quality of most of the included studies was low or very low. Methods of randomisation and allocation concealment often did not meet current standards, and 'treatment versus no treatment' was more commonly seen than 'treatment versus placebo', leading to obvious risks of bias. AUTHORS' CONCLUSIONS: We found reduced recurrence rates for intermittent
diazepam and continuous
phenobarbital, with adverse effects in up to 30% of children. The apparent benefit for
clobazam treatment in one trial needs to be replicated.
Levetiracetam also shows benefit with a good safety profile; however, further study is required. Given the benign nature of recurrent
febrile seizures, and the high prevalence of adverse effects of these drugs, parents and families should be supported with adequate contact details of medical services and information on recurrence,
first aid management, and, most importantly, the benign nature of the phenomenon.