Prophylaxis Sometimes Needed - Childhood migraine

Prophylaxis Sometimes Needed

Prophylactic treatment may be indicated for children who have migraine attacks that are prolonged, frequent (>2 severe attacks per month) or incapacitating and are not relieved by symptomatic treatment.^[3,4] Prophylaxis may also be considered if attacks predictably occur at critical times, such as during examinations. However, nondrug treatments can be highly effective and should be tried before drug therapy is initiated, and continued in a complementary role. If prophylactic drug treatment is required, it should be prescribed and individually tailored by a specialist.^[4]

When initiating prophylactic treatment, a trial of the drug for 6 to 12 weeks is warranted. If effective, the drug should be continued for 6 months and then the patient reassessed.^[4] If the first drug is not effective, a second and then a third, if necessary, can be tried.^[3]

A number of the options for migraine prophylaxis in adults, as previously reviewed [see article entitled 'A lot of ammunition but does migraine prophylaxis hit the target?' Drugs & Therapy Perspectives 1999 June 7; 13 (11): 5-8], have been investigated in children and adolescents. However, only a few drugs have proven to be effective. In the absence of a consistently effective or any one clearly superior drug, the choice of drug may be guided by the characteristics of the child and child/parent preference after discussing the adverse effect profiles of the various available agents (see table 2).^[3,4]

A Few Possible Options

The strongest evidence for efficacy is for flunarizine (see table 2). Flunarizine 5 or 10 mg/day reduces the frequency and duration of migraine in children.^[11,12] It appears to be at least as effective as comparator agents, including propranolol, aspirin and nimodipine.^[13,14,21] However, the use of flunarizine may be limited by adverse effects including bodyweight gain and drowsiness.

Propranolol appeared promising as a prophylactic agent for migraine in children at first,^[18] but later data have been less positive^[19,20] (see table 2). Despite its established efficacy in adults,^[10] propranolol can not presently be recommended as the first choice for migraine prophylaxis in children, although it may be worth trying.^[3] However, it should be remembered that the use of propranolol is contraindicated in children with asthma.

Results from double-blind, placebo-controlled trials of pizotifen have been inconsistent (see table 2).^[15,17] However, the drug does appear to have some efficacy when data from uncontrolled trials and comparative trials with lisuride and tryptophan are taken into account.^[3]

Results Equivocal for Many Drugs

At least some efficacy has been shown for a number of other drugs, including amitriptyline, papaverine, nimodipine, cyproheptadine and trazodone, but more data are needed to clarify if they will be useful prophylactic agents for migraine in children. The prophylactic effects of clonidine appear to be limited and are only seen in patients with migraine with aura.^[3,4]

Beta-Blockers and calcium antagonists other than those already discussed, NSAIDs, dihydroergotamine mesylate, tryptophan and carbamazepine have failed to show any real efficacy in this indication.^[3,4]

Valproic acid (sodium valproate) has not been tested in controlled studies in children.^[4]

Some Individuals May Benefit

Despite the less than encouraging results from many of the trials of prophylactic drugs, it is possible that some individual patients will improve dramatically with a specific drug.^[3] This may reflect the heterogenous nature of migraine.