Is it safe to use mebendazole (Vermox) in a 15-months-old child?/nThe questioner considers treating

Fråga: Is it safe to use mebendazole (Vermox) in a 15-months-old child? The questioner considers treating an otherwise healthy 15-months-old child with helminthiasis. According to the Swedish medical product catalogue (FASS) little is known about the use of mebendazole in children under 2 years of age.

Sammanfattning: The exclusion of children between 12 and 24 months of age from mebendazole treatment is due to a lack of information and not due to any reports of toxicity and adverse effects. There is a recent study supporting the use of mebendazole in this age group, and the WHO has also concluded that children as young as 12 months should be treated.

Svar: Mebendazole, a benzimidazole, is a versatile antihelmintic agent. The primary action of benzimidazoles is thought to be inhibition of microtubule polymerisation by binding to beta-tubulin. The selective toxicity of these drugs derives from the fact that specific, high affinity binding to parasite beta-tubulin occurs at much lower concentration than does binding to mammalian tubulin. Mebendazole is poorly absorbed and undergoes extensive first-pass metabolism. The systemic bioavailability is only 22 percent. The metabolites appear to be the inactive. Conjugates of mebendazole and its metabolites have been found in bile, and little unchanged mebendazole appears in the urine (1).

The manufacturer has no documentation either to support or discourage the treatment of children under two years of age. (2)

We have found one study that specifically addresses the issue of mebendazole use in children under the age of 24 months. At the start of the study, 212 children aged less than 24 months were included. At the fourth and final round of treatment, 114 children were still less than 24 months old. A total of 317 mebendazole 500 mg and 336 placebo treatments were given during one year. Data on fever, cough, diarrohea, dysentery and acute respiratorty illness were collected one week after each treatment. There was no difference in the occurrence of adverse events between the two groups (3). The authors also investigated with the original producers and several national regulatory agencies the reason for the exclusion of children under 24 months of age from mebendazole treatment. They reached the conclusion that the exclusion of this age group is due to a lack of information and not due to any reports of toxicity and adverse effects. The poor absorption of the drug and the mild and transient side effects in other age groups were considered good predictors for the absence of significant side-effects also in this age-group (3).

In 2002, WHO held an informal conference on the use of praziquantel during pregnancy and lactation and albendazole/mebendazole in children under the age of 24 months. The conclusion reached was that pregnant and lactating women and children as young as 12 months should be treated (4).

It is important to point put that one cannot, from these data, assume that it would also be safe to treat children under 12 months of age. There is no documentation supporting treatment of that age group and there are reports of seizures associated with mebendazole treatment in children less than one year old (5).