Questions on Prevacid and Prilosec:

        These two products belong to the new family of drugs called
proton-pump inhibitors.  They very efficiently block the hydrogen pump in
the parietal cell of the stomach,  effectively blocking acid production in
the stomach.  As a group,  they are incredibly potent, and effective at
blocking acid production in hypersecretory states.  They are used in
patients with stomach ulcers,  gastroesophageal reflux, and hypersecretory
acid states.   Generally,  we like to reserve this group for those patients
that do not respond to Zantac, Tagamet, Pepcid, Axid,  etc(H-2 blockers).
If these products(H-2 blockers) don't work,  then we use the proton pump
inhibitors.   When evaluating the H-2 antagonists,  we find that Zantac and
Tagamet have high Milk:Plasma  ratios and generally higher milk
levels(although absolute dose transferred to infant is probably minimal).
Pepcid(famotidine)  and Axid(Nizatidine) generally have lower milk
concentrations and are probably preferred H-2 blockers for lactating women.

          If,  however,  these agents do not work,  then the proton pump
inhibitors are used.   Prilosec is incredibly effective,  and raises gastric
pH significantly.  However,  it is incredibly expensive,  and the long term
sequelae of elevating gastric pH is questioned.  In some animal studies,
long term(yrs) use of these agents has led to gastric carcinoma.   Nature
intended for the stomach to have a low pH.  Raising it for long periods of
time theoretically causes problems.

        We have NO information on breastmilk levels of Prilosec or Prevacid.
They are weak bases which may lead to higher milk levels,  but their plasma
half-life is extremely short.   They irreversibly bind to the proton pump
and are active for over 72 hours.   In general,  I would suggest that their
overall danger to a breastfeeding infant would be very low if the exposure
was not prolonged,  such as 3-4 months,  but I would suggest the H-2
blockers first,  and then the proton pump inhibitors.

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T.W. Hale, Ph.D.
Associate Professor of Pediatrics
Texas Tech University School of Medicine

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