Treatment of febrile seizures with intermittent clobazam

Prophylactic drug management for febrile seizures in children (Review)

BACKGROUND

Febrile seizures occurring in a child older than one month during an episode of fever affect 2% to 4% of children in Great Britain and the United States and recur in 30%. Rapid-acting antiepileptics and antipyretics given during subsequent fever episodes have been used to avoid the adverse effects of continuous antiepileptic drugs.

OBJECTIVES

To evaluate the effectiveness and safety of antiepileptic and antipyretic drugs used prophylactically to treat children with febrile seizures.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011. Issue 3); MEDLINE (1966 to May 2011); EMBASE (1966 to May 2011); Database of Abstracts of Reviews of Effectiveness (DARE) (May 2011). No language restrictions were imposed. We also contacted researchers in the field to identify continuing or unpublished studies.

SELECTION CRITERIA

Trials using randomised or quasi-randomised patient allocation that compared the use of antiepileptic or antipyretic agents with each other, placebo or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors (RN and MO) independently applied pre-defined criteria to select trials for inclusion and extracted the pre-defined relevant data, recording methods for randomisation, blinding and exclusions. Outcomes assessed were seizure recurrence at 6, 12, 18, 24, 36 months and at age 5 to 6 years in the intervention and non-intervention groups, and adverse medication effects. The presence of publication bias was assessed using funnel plots.

MAIN RESULTS

Thirty-six articles describing 26 randomised trials with 2740 randomised participants were included. Thirteen interventions of continuous or intermittent prophylaxis and their control treatments were analysed. Methodological quality was moderate to poor in most studies. We could not do a meta-analysis for eight of the 13 comparisons due to insufficient numbers of trials. No significant benefit for valproate, pyridoxine, intermittent phenobarbitone or ibuprofen versus placebo or no treatment was found; nor for diclofenac versus placebo followed by ibuprofen, acetominophen or placebo; nor for intermittent rectal diazepam versus intermittent valproate, nor phenobarbitone versus intermittent rectal diazepam. There was a significant reduction of recurrent febrile seizures with intermittent oral diazepam versus placebo with a relative risk (RR) of 0.67 (95% confidence interval (CI) 0.48 to 0.94) at 24 months), RR of 0.61 (95% CI 0.15 to 0.89) at 48 months, with no benefit at 6, 12 or 72 months. Phenobarbitone versus placebo or no treatment reduced seizures at 6, 12 and 24 months but not at 18 or 72 month follow up (RR 0.60, 95% CI 0.42 to 0.84 at 6 months; RR 0.59, 95% CI 0.46 to 0.75 at 12 months; and RR 0.65, 95% CI 0.49 to 0.88 at 24 months). Intermittent rectal diazepam versus no treatment or placebo also reduced seizures (RR 0.60, 95% CI 0.41 to 0.86 at 6 months; RR 0.65, 95% CI 0.49 to 0.87 at 12 months; RR 0.2, 95% CI 0.1 to 0.39 at 18 months; RR 0.36, 95% CI 0.18 to 0.71 at 36 months), with no benefit at 24 months. Intermittent clobazam compared to placebo at 6 months resulted in a RR of 0.09 (95% CI 0.02 to 0.30), an effect found against an extremely high (83.3%) recurrence rate in the controls and which is a result that needs replication. The recording of adverse effects was variable. Lower comprehension scores in phenobarbitone treated children were found in two studies. In general, adverse effects were recorded in up to some 30% of children in the phenobarbitone treated group and in up to 36% in benzodiazepine treated groups. Evidence of publication bias was found in the meta analyses of comparisons for phenobarbitone versus placebo (8 studies) at 12 months but not at 6 months (6 studies); and valproate versus placebo (4 studies) at 12 months; with too few studies to identify publication bias for the other comparisons.

AUTHORS' CONCLUSIONS

No clinically important benefits for children with febrile seizures were found for intermittent oral diazepam, phenytoin, phenobarbitone, intermittent rectal diazepam, valproate, pyridoxine, intermittent phenobarbitone or intermittent ibuprofen, nor for diclofenac versus placebo followed by ibuprofen, acetominophen or placebo. Adverse effects were reported in up to 30% of children. Apparent benefit for clobazam treatment in one recent trial needs to be replicated to be judged reliable. 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.

Prophylactic drug management for febrile seizures in children

BACKGROUND

Febrile seizures occurring in a child older than one month during an episode of fever affect 2% to 4% of children in Great Britain and the United States and recur in 30%. Rapid-acting antiepileptics and antipyretics given during subsequent fever episodes have been used to avoid the adverse effects of continuous antiepileptic drugs.

OBJECTIVES

To evaluate the effectiveness and safety of antiepileptic and antipyretic drugs used prophylactically to treat children with febrile seizures.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011. Issue 3); MEDLINE (1966 to May 2011); EMBASE (1966 to May 2011); Database of Abstracts of Reviews of Effectiveness (DARE) (May 2011). No language restrictions were imposed. We also contacted researchers in the field to identify continuing or unpublished studies.

SELECTION CRITERIA

Trials using randomised or quasi-randomised patient allocation that compared the use of antiepileptic or antipyretic agents with each other, placebo or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors (RN and MO) independently applied pre-defined criteria to select trials for inclusion and extracted the pre-defined relevant data, recording methods for randomisation, blinding and exclusions. Outcomes assessed were seizure recurrence at 6, 12, 18, 24, 36 months and at age 5 to 6 years in the intervention and non-intervention groups, and adverse medication effects. The presence of publication bias was assessed using funnel plots.

MAIN RESULTS

Thirty-six articles describing 26 randomised trials with 2740 randomised participants were included. Thirteen interventions of continuous or intermittent prophylaxis and their control treatments were analysed. Methodological quality was moderate to poor in most studies. We could not do a meta-analysis for eight of the 13 comparisons due to insufficient numbers of trials. No significant benefit for valproate, pyridoxine, intermittent phenobarbitone or ibuprofen versus placebo or no treatment was found; nor for diclofenac versus placebo followed by ibuprofen, acetominophen or placebo; nor for intermittent rectal diazepam versus intermittent valproate, nor phenobarbitone versus intermittent rectal diazepam.There was a significant reduction of recurrent febrile seizures with intermittent oral diazepam versus placebo with a relative risk (RR) of  0.67 (95% confidence interval (CI) 0.48 to 0.94) at 24 months), RR of 0.61 (95% CI 0.15 to 0.89) at 48 months, with no benefit at 6, 12 or 72 months. Phenobarbitone versus placebo or no treatment reduced seizures at 6, 12 and 24 months but not at 18 or 72 month follow up (RR 0.60, 95% CI 0.42 to 0.84 at 6 months; RR 0.59, 95% CI 0.46 to 0.75 at 12 months; and RR 0.65, 95% CI 0.49 to 0.88 at 24 months). Intermittent rectal diazepam versus no treatment or placebo also reduced seizures (RR 0.60, 95% CI 0.41 to 0.86 at 6 months; RR 0.65, 95% CI 0.49 to 0.87 at 12 months; RR 0.2, 95% CI 0.1 to 0.39 at 18 months; RR 0.36, 95% CI 0.18 to 0.71 at 36 months), with no benefit at 24 months. Intermittent clobazam compared to placebo at 6 months resulted in a RR of 0.09 (95% CI 0.02 to 0.30), an effect found against an extremely high (83.3%) recurrence rate in the controls and which is a result that needs replication.The recording of adverse effects was variable. Lower comprehension scores in phenobarbitone treated children were found in two studies. In general, adverse effects were recorded in up to some 30% of children in the phenobarbitone treated group and in up to 36% in benzodiazepine treated groups. Evidence of publication bias was found in the meta analyses of comparisons for phenobarbitone versus placebo (8 studies) at 12 months but not at 6 months (6 studies); and valproate versus placebo (4 studies) at 12 months; with too few studies to identify publication bias for the other comparisons.

AUTHORS' CONCLUSIONS

No clinically important benefits for children with febrile seizures were found for intermittent oral diazepam, phenytoin, phenobarbitone, intermittent rectal diazepam, valproate, pyridoxine, intermittent phenobarbitone or intermittent ibuprofen, nor for diclofenac versus placebo followed by ibuprofen, acetominophen or placebo. Adverse effects were reported in up to 30% of children. Apparent benefit for clobazam treatment in one recent trial needs to be replicated to be judged reliable. 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.

Diazepam versus clobazam for intermittent prophylaxis of febrile seizures

OBJECTIVE

To compare the effectiveness of intermittent clobazam versus diazepam therapy in preventing the recurrence of febrile seizures and assess adverse effects of each drug.

METHODS

This prospective randomized controlled trial was performed on neurologically normal children aged from 6 months to 5 years with a history of simple febrile seizures and normal electroencephalogram without any evidence of acute central nervous system infection. The patients were randomly prescribed with oral clobazam (37 cases) or diazepam (35 cases) when they developed a febrile disease. They were advised to use the medications during the first 48 h of the onset of fever. All the patients were monitored regarding developing seizure and adverse effects of the drugs. All patients were followed for 12 months.

RESULTS

Overall, 243 episodes of fever occurred during the period, including 116 episodes in the clobazam group and 127 episodes in the diazepam group. Recurrence of seizures occurred in 2 (1.7%) subjects in the clobazam group, and in 4(3.1%) cases in the diazepam group. (P value=0.474). Twenty cases (54%) in the diazepam group and 5 (14.2%) cases in the clobazam group developed drowsiness and sedation during the follow-up period (P value=0.0001).

CONCLUSIONS

Intermittent clobazam therapy seems advantageous to diazepam due to similar efficacy but significantly lower adverse effects such as drowsiness and sedation.

Treatment of febrile seizures: historical perspective, current opinions, and potential future directions

Although most febrile seizures do no harm and two-thirds of initial cases have no witnessed recurrence, the seizures cause much family anxiety, and are sometimes prolonged. In rare cases they are the first evidence of important epilepsy syndromes or are implicated in the development of epilepsy with mesial temporal sclerosis in later life. There have been trials of prophylactic treatment with antiepileptic drugs including carbamazepine, diazepam, phenobarbital, phenytoin, and sodium valproate. Several strategies have been employed with these drugs, including continuous secondary prophylaxis, intermittent secondary prophylaxis in response to later episodes of fever, and rescue medication early in the course of further seizures. Another treatment strategy has been using one or more antipyretic agents in early response to fever using agents such as acetaminophen and ibuprofen. Over the years, researchers have identified a variety of clinical, genetic, and environmental risk factors for more severe or prolonged febrile seizures and higher risk of recurrence. This review evaluates the rationale for secondary prophylaxis of febrile seizures, the potential effectiveness of such treatment, and whether it can be recommended as a general approach to treating febrile seizures or as an approach to be used in groups identified to be at increased risk.

Intermittent clobazam therapy in febrile seizures

OBJECTIVE

To evaluate the efficacy of intermittent clobazam therapy in preventing the recurrence of febrile seizures and to assess its safety.

METHODS

The study was a prospective, randomized, double-blind placebo-controlled trial conducted in the Department of Child Health, Christian Medical College Hospital, Vellore between July 2001 and September 2002. Neurologically normal children between 6 months and 3 years of age with a history of febrile seizures and no evidence of acute CNS infection or EEG abnormality were included into the study. 19 children in a clobazam group and 20 in the placebo group were randomly allocated. Temperature reduction measures with paracetamol and tepid sponging were advised to all children. In addition the dispensed medication was to be administered at the onset of fever and continued for 48 hours irrespective of the duration of fever. The children were then monitored for seizures and adverse effects of clobazam. The children were followed up for a mean period of 9.9 months. The analysis was done on the number of febrile episodes in both the groups.

RESULTS

There were a total of 110 episodes of fever during the study period. Mean number of febrile episodes in the clobazam group was 3.1 and in placebo group 2.56. Six (12.5%) of the 48 episodes in placebo group and one (1.7%) of 60 episodes in clobazam group had seizure recurrence. This was statistically significant (p = 0.01). Drowsiness and weakness were present equally in both clobazam and placebo groups whereas ataxia was present only in the clobazam group, the difference being statistically significant (p=0.04).

CONCLUSION

Intermittent clobazam therapy is an effective measure in the prevention of recurrence of febrile seizures. The ataxia due to clobazam was much lower than that reported with diazepam.