Linda,
Sounds like this mom is just experiencing the roller coaster effect of a
returning menstrual cycle that will possibly be irregular for many months
(years) to come.  The antibiotics is probably a non-contributing factor.
Lansinoh would probably not help.  Mother needs to stay hydrated &
probably space feedings out during the tenderness days.  As soreness
dissapates (within two-four days), toddler will increase feedings to get
milk supply back up.  Also, a grin & bear it approach also is needed
though not fun.  Personal experience with this!

Lora Gleaton