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Once again you find yourself in a busy general paediatric clinic faced with a 14 year old girl suffering from recurrent headaches for the past nine months. The history would suggest frequent attacks of a migrainous nature without aura. There is a positive family history in both parents and a sibling, but no obvious precipitating factors. The attacks are now occurring weekly and interfering with normal activities, especially school attendance. She is due to start GCSE coursework soon and both her and her parents are very keen to try a preventative medication. Her neurological examination is normal. They would like her on pizotifen or propranolol as these have helped other family members in the past. She is not asthmatic and otherwise healthy.
Structured clinical question
In an adolescent with frequent migrainous headache [patient] does the prescription of pizotifen or propranolol [intervention] reduce the frequency and/or the severity of migraine attacks [outcome]?
Search strategy and outcome
The data were derived from the results of a search carried out in 2003 by an information specialist at Clinical Evidence.
Secondary sources: The Cochrane Library, Issue 4, 2003—one relevant review found.1
Primary sources: Medline 1966 to date, Embase 1980 to date, Psycinfo 1980 to date. The search terms used were: migraine AND child OR infant OR pediatric OR paediatric OR schoolchild OR teen OR teenager OR adolescent. This strategy yielded 36 systematic reviews and a further 51 randomised controlled trials. The majority were excluded as they were either irrelevant or of poor quality, leaving just five articles (see tables 1 and 2).
Studies in the developed world suggest that migraine is the commonest diagnosis among children presenting to a medical practitioner with headache. There are well defined diagnostic criteria laid down by the International Headache Society.2 Girls and boys are affected equally before puberty, but thereafter girls are more likely to suffer migraine.2–4 Propranolol and pizotifen are widely prescribed by paediatricians as prophylactic agents.
No systematic reviews were available on the use of β blockers, though three RCTs with conflicting results were identified which compared propranolol with placebo. Ludviggson5 showed in 32 children aged 7–16 years that propranolol (60–120 mg in three divided doses) produced a significant increase in the perception of benefit compared with placebo. Forsythe and colleagues6 showed that propranolol (40–120 mg daily) actually increased headache duration compared with placebo in 53 children aged 9–15 years. Olness and colleagues7 found no significant difference in the number of migraine attacks between propranolol (3 mg/kg per day) and placebo in 33 children aged 6–12 years. No significant harmful side effects were reported in any of these patient groups. All three studies had methodological flaws, and all, because of their small size, probably lacked the power to exclude clinically important differences and to yield important information about harms. The interpretation of post-crossover results in these three RCTs is unreliable because the short washout period may introduce a confounding effect.
Very little data were found on the use of pizotifen in this setting. No systematic reviews were identified. One RCT by Gillies and colleagues8 predated the IHS diagnostic criteria and not all participants in this study would fulfil the current criteria.2 This study failed to show any benefit for pizotifen over placebo. An RCT by Salmon9 was only published in abstract form and indicated that this study was from a mixed patient group, only some of whom had “classical” migraine. Furthermore, very limited numerical results are included in this abstract and so the conclusions of this study are unreliable on strength of the information provided.
CLINICAL BOTTOM LINE
There have only been three studies on the use of propranolol as prophylaxis in migraine, and each differs in its conclusion:1 one suggested a benefit,4 a second suggested no benefit,6 and a third concluded that it may actually worsen symptoms.5
There is no reliable published data to support the use of pizotifen in migraine prophylaxis.1
We thank Clinical Evidence for the use of data from a search carried out by them in 2003.
N Barnes, Specialist Registrar, John Radcliffe Hospital, Oxford, UK;
G Millman, Specialist Registrar, Royal Manchester Children’s Hospital, Manchester, UK