The association of severe hyponatremia and the ingestion of large quan
tities of beer, termed beer potomania, has been known for several year
s. We report two new cases, and review 20 others from the medical lite
rature. These patients usually have a history of binge beer drinking,
poor dietary intake, and then present with severe hyponatremia and var
ious mental status changes or seizures, Typical laboratory findings in
clude hyponatremia, hypokalemia, and a very dilute urine. The patients
respond quickly to the administration of sodium chloride containing I
V fluids. We propose that the pivotal pathophysiologic mechanism in be
er potomania syndrome is the minimal intake of solute and the hypoosmo
lality of the beer ingested. This will lead to the inability to excret
e sufficient amounts of free water to keep up with the ingestion of la
rge quantities of the hyposmolar beer. Treatment with isotonic sodium
chloride results in the rapid clearance of the accumulated excess free
water.