I am interested in the dialog about mag sulfate.  It has been my clinical
observation that some infants whose mothers have been given mag sulfate are
temporarily poor feeders.  I have long wondered why this should be so as the
lit suggests, as Dr. Hale reminds us, that this drug is compatible with bfg.
I came across the following in Pediatrics in Review, 1996, 17(3):104-5, in
the "In Brief" column in a review titled "Hypotonia in Infants," by L
Stiefelm MD, from Mt Sinai Medical Center in NY.

"Drugs have been found to interrupt function at the neuromuscular junction
and cause hypotonia.  Hypermagnesemia can occur secondary to the treatment
of severe exlampsia with magnesium sulfate.  The high levels of magnesium
block the release of acetylcholine from the nerves and cause weakness,
hyporeflexia, and increased risk of respiratory failure in the infant.  The
diagnosis is established by checking serum magnesium levels. Treatment is
supportive.

Aminoglycoside antibiotics such as gentamicin, neomycin, and streptomycin
can disrupt the presynaptic release of acetylcholine and cause hypotonia and
areflexia.  Management of affected infants is supportive."

I was grateful to have that piece of the puzzle and hope it will be useful
to others.  I wouldn't suggest the mom not be treated, nor worry overmuch
about the infant since, as the author suggests, the best measures are
supportive.  But in my mind, when I screen for factors which might be
suggestive of a reason for poor feeding, I now consider transient hypotonia
due to exposure to mag. sulfate.

Barbara


Barbara Wilson-Clay, BS, IBCLC
Private Practice, Austin, Texas
Owner, Lactnews On-Line Conference Page
http://moontower.com/bwc/lactnews.html