Posted by SalArmy4me on July 13, 2001, at 8:35:46
Wight gain with atypical antipsychotics is due to the drugs' antihistaminergic and anticholinergic effects. Also, weight gain occurs more frequently in the first few weeks of treatment, and among the young.
Journal of Clinical Psychopharmacology
Volume 19(4) August 1999 pp 316-321
Weight Gain: Side Effect of Atypical Neuroleptics?
Wetterling, Tilman MD, PhD; MuBigbrodt, Heidi E. MD:"...Many drugs with an anticholinergic effect such as most so-called low-potency neuroleptics and clozapine may induce a dry mouth and thereby stimulate thirst. Therefore, patients complaining of a dry mouth may drink excessively. If they consume large amounts of high-calorie drinks, they may gain weight. Receptor studies revealed that clozapine, zotepine, and low-potency phenothiazine derivatives such as thioridazine have a high affinity at the muscarinic-acetylcholine (M1) receptor, whereas benzamide, butyrophenone, and piperidine derivatives show a rather low M1 affinity. [2] However, because sulpiride, with no significant anticholinergic effects, also induces weight gain, there is no clear relationship between the M1 affinity and the increase of weight. Furthermore, thus far no relationship between weight gain and anticholinergic comedication (such as biperiden) has been found.
The time frame of weight gain is discussed controversially in the literature (see [13] for review). Although in one survey [17] weight gain most frequently occurred after long-term medication ( >18 months), other investigators reported a high rate of weight increase during the first 3 months of neuroleptic treatment. [5,6,13] In this study, weight gain most frequently occurred during the first 5 weeks of medication, particularly in patients who were not previously medicated. Moreover, those patients observed in more than one treatment episode showed a lower increase of weight in later treatment episodes. As seen in this study, weight gain correlates neither with the duration of treatment nor with the chlorpromazine-equivalent dosage. [15]
..._Young_ subjects, previously not treated with neuroleptics, have a higher risk of weight gain, particularly if they are receiving new atypical neuroleptics. [25,26] Therefore, this side effect has to be taken seriously in view of the compliance with long-term neuroleptic medication, because as is known from the experience with lithium salt medication, weight gain is associated with a high rate of refusal of any further medication..."
poster:SalArmy4me
thread:69974
URL: http://www.dr-bob.org/babble/20010708/msgs/69974.html