Posted by SalArmy4me on September 4, 2001, at 23:15:59
In reply to Amphetamines and Growth, posted by Nick Caruso on September 4, 2001, at 18:57:16
Casat, Charles D. MD. Hartnagel, William MD. APPETITE AND WEIGHT IN CHILDREN TREATED FOR ADHD. Journal of the American Academy of Child & Adolescent Psychiatry. 38(7):792-793, July 1999:
"Appetite suppression is a common accompaniment of stimulant use in children with attention-deficit/hyperactivity disorder (ADHD). Not infrequently, there is a slowing in growth parameters with stimulant treatment, although the ultimate impact of stimulants on growth has been characterized as negligible. In some children, however, weight loss may be significant, leading the clinician and parent to consider stopping treatment. This may present a considerable dilemma because the symptoms themselves may lead to exclusion from important academic and social experiences vital to a child's development.
In the accompanying Letter to the Editor, Dr. Callaghan has described several examples from his practice of children whose weight loss was apparently reversed when bupropion was added to each child's stimulant medication regimen. However, it is not clear whether stimulant dose was reduced as bupropion was added, and the daily dosing was not described. Also, the presence of any comorbid clinical conditions, especially depression, was not mentioned.
Appetite is under complex control of endocrine (insulin and leptin) and neural (norepinephrine, opioids, and neuropeptide Y) mechanisms, mediated especially through the ventromedial hypothalamus (Kalra, 1997) [4]. Although progress has been made recently in understanding the control of appetite, much remains still to be elucidated. With regard to weight changes associated with medications, a large variety of drugs will impact such changes. Those with significant histamine-blocking effect will generally dispose to weight gain, while medications with significant noadrenergic activity may cause weight loss.
The mechanism(s) of bupropion action is thought to involve enhancement of extracellular dopamine levels, the down-regulation of the locus ceruleus, decrease of tyrosine hydroxylase activity, and net improvement of the functional efficiency of norepinephrine (Davidson and Connor, 1998) [3]. Bupropion has no antihistaminic or serotonergic effects (Settle, 1998) [5]. Its net effect on weight across studies in adults is generally reported as being of negligible consequence or of inducing mild weight loss. Two short-term, double-blind studies of bupropion in children with ADHD have been published, including a 4-week, multisite comparison of bupropion (n = 72) and placebo (n = 37) reported by Conners et al. (1996) [2] and a 15-subject cross-over study of bupropion and methylphenidate reported by Barrickman et al. (1995), [1] with 6 weeks in each arm and an intervening 2-week washout period. Weight change was not specifically referred to in the studies. However, unpublished data from the Conners et al. (1996) [2] study (data on file at Glaxo Wellcome) showed no significant weight change among the 72 children receiving bupropion during the 4-week trial.
Bupropion is a useful drug for the management of ADHD in a subset of children who cannot tolerate stimulants. It also possesses the advantages that it has little abuse potential and no cardiac side effect profile. However, its use as an adjunctive orexigenic medication for children on stimulants who experience weight loss is not supported by the existing literature or by the putative mechanisms of action. Its usefulness in combination with stimulants in children with ADHD has not been systematically evaluated to date, but one would conjecture that the negative effects on appetite would most likely be additive. Other than the thoughts put forth above regarding the possible effects on comorbid depressive symptoms in the children, there is no current explanation for the weight gain observed by Dr. Callaghan.
Other strategies commonly used for minimizing the anorectic effects of stimulants include changing to another stimulant or to another class of drug, changing the timing of administration (e.g., making sure that medication is always given after meals), changing the preparation (e.g., from short-acting to a longer-acting form), and enforcing drug holidays. The hope is that, for the future, other classes of drugs with specific symptom-reducing, attention-focusing properties will be developed that will have a less negative impact on appetite and weight for children requiring medication for ADHD."
poster:SalArmy4me
thread:13193
URL: http://www.dr-bob.org/babble/20010902/msgs/77768.html