The new "wonder" antidepressants have been shown to promote cancer growth in some preliminary animal studies.
According to an article published in GP (17 July), Canadian cancer researchers found that amitriptyline and fluoxetine promote the growth of tumours in rats and mice.
Both are among the class of drugs inelegantly referred to as serotonin reuptake inhibitors, which have been hailed as wonder cures for everything from depression to migraines.
The animals given either drug developed mammary tumours 30 to 40 per cent more rapidly than did controls given sugar pills, and 2.5 times as many tumours. A second study confirmed the results of the first. The researchers of Manitoba Institute of Cell Biology, led by Dr Lorne Brandes, emphasize that they have no evidence of a cancer link between the drugs and humans. Nevertheless, she says, "The question has to be asked: 'Are the drugs people taking promoting cancer?'"
Although Eli Lilly, which manufactures fluoxetine, issued a statement denying any health implications from the study, DDSA Pharmaceutical, which markets amitriptyline in the UK, called for more studies.