|
You are here: Home: BCU Surgeons Vol.2 Issue 4: Charles Loprinzi, MD
Edited comments by Dr Loprinzi
Management of vasomotor symptoms in breast cancer survivors
Hot flashes are a major problem for many women during menopause, but they can be even more of a problem in women with breast cancer for a number of reasons. We may induce premature menopause with chemotherapy or exacerbate hot flashes with tamoxifen, and we deny the woman estrogen. While there are fewer hot flashes with the aromatase inhibitors than with tamoxifen, some women on aromatase inhibitors experience hot flashes.
We started looking at the management of hot flashes over a decade ago, and have found a number of effective therapies. Clonidine was one of the earliest agents studied, and while placebo decreases hot flashes by about 25 percent from baseline, clonidine decreases them by another 15 percent to 20 percent. There are, however, a number of side effects, and many patients did not like clonidine. Vitamin E has a small effect, decreasing symptoms by approximately one hot flash per person per day. Megestrol acetate reduces hot flashes by approximately 80 percent, a reduction comparable to that achieved by administration of estrogen. However, some people are as concerned about giving progesterone to a breast cancer survivor as they are about giving estrogen.
These observations led us to look at the newer antidepressants. We conducted a dose-finding, placebo-controlled trial of venlafaxine, wherein we saw that a placebo decreased hot flashes by 27 percent. A dose of 37.5 mg per day of venlafaxine in a sustained-release preparation decreased hot flashes by 40 percent from baseline, and a 75 mg dose decreased hot flashes by about 60 percent from baseline. Raising the dose to 150 mg did not result in additional improvement. These are relatively low doses, compared to the 150 mg and 225 mg generally used to treat depression.
We are also looking at a number of newer antidepressants. In addition to studying venlafaxine, we published a trial with fluoxetine, demonstrating a significant reduction in hot flashes - though not quite the magnitude of effect we saw with venlafaxine. We didn't, however, look at multiple doses like we did with venlafaxine. Other pilot trials suggest that other antidepressants like citalopram, paroxetine and other newer antidepressants have a similar effect.
We are also studying the antiseizure medication gabapentin, which demonstrated a 60 percent reduction in hot flashes in a pilot study. Some people experience lightheadedness, dizziness, some fatigue during the day and some edema while taking gabapentin, but for many patients, it is well-tolerated.
Usually patients will have tried Vitamin E before they see me. It is nontoxic, well-tolerated, inexpensive, readily available and it results in a slightly greater reduction in hot flashes than the placebo effect. After first trying Vitamin E, I move on to venlafaxine, starting at 37.5 mg and increasing to 75 mg if necessary. This is usually effective for 40 percent of patients. I have been using gabapentin next in practice. This helps another 20 percent of women. My next intervention is generally medroxyprogesterone acetate 500 mg IM every 14 days for three doses. I do tell my patients that at the current time we don't know the effect of progesterone on breast cancer.
Select publications
|
