Childhood Obesity in the United Kingdom 93beyond 12 months, or on considerations of duration of treatment or strategies
for compliance.
Metformin has been shown to be relatively well tolerated by children and
adolescents, with McDonagh’s systematic review highlighting discontinuation
of Metformin due to adverse effects occurring in just 1.6% of patients taking
Metformin [64]. The most serious side effect of Metformin is lactic acidosis,
although no known cases in children have been reported in the literature [64].
Common side effects of Metformin are mostly gastrointestinal, including
nausea, abdominal pain and diarrhoea. Studies indicate mild side effects only,
settling with temporary reduction of Metformin dose [63]d. In a randomised
controlled trial, side effects were most common in the first month of treatment
but at the end of the treatment period there was no significant difference in
reported side effects between children on Metformin and children taking a
placebo [66].
Octreotide
Octreotide has been noted to be effective in the treatment of paediatric
patients with hypothalamic obesity [67]. Hypothalamic obesity is a well-
recognised condition, which can occur following brain tumours or radiation to
the brain. There are two main theories regarding hypothalamic obesity. The
first is that structural damage to the ventromedial hypothalamus causes
hyperphagia, since the ventromedial hypothalamus specifically is thought of as
the satiety centre. The other commonly described theory is that damage to the
ventromedial hypothalamus disinhibits the vagus nerve, resulting in
stimulation of pancreatic beta cells, which in turn produces very large amounts
of insulin. Octreotide is a somatostatin analogue, and so is able to bind to the
somatostatin receptor-5 on the membrane of the beta cell. In this way,
Octreotide limits the release of insulin. In 2003, results of a key double blind
placebo controlled trial investigating use of Octreotide were published,
demonstrating beneficial effects of Octreotide on both weight loss and insulin
suppression in children with hypothalamic obesity [67].
The Future: Future Drug Therapies for the UK
There are a number of drugs that have been licensed for use in managing
obesity in adults in the USA recently. These drugs represent the probable
future of medical therapy for obesity in children. It is likely to be several years
though before licensing is achieved in children and indeed in the UK.