Tamoxifen does not act directly, but it must be transformed in its active metabolite, endoxifen, by 2D6 isoenzyme of P450 cytochrome. In women affected by early-stage breast cancer sensitive to estrogenic receptors, tamoxifen decreases the risk of relapses of about 50% and the risk of death for cancer of about 30%. Many of these women, however, are also under therapy with SSRI antidepressants, both for cancer-related depression and to decrease hot flushes caused by tamoxifen. But the problem is in the fact that SSRIs, and paroxetine in particular, inhibits 2D6 isoenzyme and consequently they could reduce the protective efficacy of tamoxifen. With a cohort trial, researchers have tried to establish whether the use of SSRIs implies an increase in specific mortality in women treated with tamoxifen or not: out of 2430 women (averagely 74 years of age) treated with tamoxifen for averagely 4 years and under SSRI therapy, there have been 374 deaths (15%) for breast cancer. Paroxetine has been the most used antidepressant, and the risk of death resulted higher in women using this drug: after various adjustments, it was seen that the increase of 25%, 50% and 75% in the assumption time of tamoxifen together with paroxetine implied an increase respectively of 24%, of 54% and of 91% in the risk of cancer mortality. With other SSRIs this association was not recorded.
(Farmacologia)
Il nostro commento:
Agosto 2010
-
Audio veloce - File size: 1899 Kb Tempo 2,1 min.
-
Audio lento - File size: 2094 Kb Tempo 2,14 min.
In subjects with smoke habit wanting to quit their addiction, a treatment of at least 8 weeks, [...]
In the prevention of relapses of bipolar disorders, lithium carbonate, sodium valproate or both [...]
The use of opioids trying to control chronic pain is more and more increasing, but, as a [...]