Sotalol is a beta blocker.  Like all medications, it gets into the milk
in small amounts.  It gets into the milk in greater amounts than other
beta blockers, because it is very poorly protein bound.  Another beta
blocker would be much safer for breastfeeding.  Propranalol could be
used.  If sotalol must be used, mother could still breastfeed.

Other categories of drugs might be used, but I am not sure exactly
which.

Jack Newman, MD, FRCPC