Finasteride and anti-androgens - do you need both?

[steepholm.livejournal.com]

I've been on 1mg daily of finasteride (Propecia) for about 3 years now - ever since I began to get a small amount of baldness on my crown. It seems to have done the trick, because the patch hasn't grown, and in fact the hair has largely grown back. So far, so good.

Anyway, I started on oestrogen about five months ago, and have recently started the anti-androgen triptorelin (Decapeptyl) as well. My question is this. Since the anti-androgen works by suppressing the production of testosterone, and therefore presumably of its by-product DHT which causes male pattern baldness, is it necessary/advisable for me to continue with the finasteride? Or does the anti-androgen make it redundant?

The finasteride costs me over £40 a month, which I've got a lot of other uses for, so if I could safely stop using it I'd be happy - but I don't want to take any unnecessary risks with my precious tresses.