Metoclopramide is not used often here, but sulpiride (which is a similar
medication, I believe) is used a lot.  I have worked with several mothers
who have taken sulpiride for an extended time, 6 - 8 months.  And I had one
personal friend who took it for 3 years while nursing.  Although it is not
addictive, I blieve mothers may become psychologically hooked on it.  It
needs to be tailed off when the mom no longer needs it, or there is a sharp
drop in breastmilk production.

Pamela, Zimbabwe