Kathleen:

For sore nipples associated with Reynaud's or Reynaud's-like symptoms, Dr.
Newman firstly recommends warmth after feeds - he recommends dry heat over
wet.  If that is ineffective he suggests Nitroglycerin paste - to vasodilate
since it seems the cause of the pain is blood vessel constriction.  When
using the paste he suggests its use immmediately after a feed and if that
works, then wait after the next feed for a period of time before applying.
I do not know the particulars of dosage or if mom must clean nipples prior
to next feed.  Being a former ICU nurse, I would be quite cautious and
contact him for more details.

Debbie Shinskie RN CES IBCLC
Home health/private practice/education in Central PA