Childhood Obesity in the United Kingdom 91analysis carried out by Czernichow et al. [55] examined a different group of
studies [53, 54, 56] and concluded that Orlistat resulted in an even greater
reduction in BMI of 1.67kg/m^2 , with weight loss averaging 6kg.
Orlistat is typically given at a dose of 120mg three times a day with meals
[43]. The main side effects associated with Orlistat are gastrointestinal,
occurring in up to 50% patients [53, 12]. These include: flatulence; oily loose
stools; oily spotting; faecal urgency; and faecal incontinence [57].^ Not
surprisingly, this side effect profile is known to lead to poor compliance
amongst some adolescent patients [43]. Another important effect is that
Orlistat can lead to poor absorption of some fat soluble vitamins, in particular
of beta-carotene and Vitamin E, meaning supplementation is recommended
[58].
Fewer studies have investigated use of Orlistat in younger children.
Norgren et al. carried out a pilot study in Sweden examining the effects of
Orlistat in 11 severely obese children aged 8.3-12.3 years, for a 12-week
period [59]; their findings indicated that the participants tolerated the treatment
well and were able to reduce their fat intake to manage side effects. A median
weight loss of 4kg was reported, which was significantly correlated with a
decrease in body fat. The authors reported that all children and guardians
expressed an interest in continuing with Orlistat after the trial period ended
[59].
Overall, whilst Orlistat remains the most commonly prescribed medication
in the management of childhood obesity, its use in children in the UK is often
limited by its side effect profile and only modest effects on weight loss.
Subsequently, much time and effort is being invested in developing alternative
medical treatment options.
Metformin
Metformin is a biguanide derivative, which acts as an oral
antihyperglycaemic agent to reduce blood sugar levels. It achieves this by
improving sensitivity to insulin in peripheral tissues, and both reducing hepatic
glucose production and absorption of glucose in the intestines [60]. Metformin
is used widely in treatment of diabetes mellitus, and is approved by the FDA
for treatment of type 2 diabetes mellitus in children over 10 years of age.
Metformin is not currently licensed for use in treating obesity in children,
however a UK population-based study published in 2012 analysed prescribing
data over a period of 10 years from 2000-2010. The results showed an increase
in Metformin prescribing, particularly between girls aged 16-18 years.
Metformin was prescribed to manage obesity alone in 7.6% of patients (n=22).