Low specific gravity syndrome.

Data strongly suggestthat the longer patients have been treated in New Castle State Hospital, the higher the probability that they will demonstrate the low specific gravity syndrome. It is believed that a probably unrecognized alteration in human water metabolism among institutionalized patients who have chronic, severe epilepsy and who have been administered anticonvulsant drugs for many years has been documented. The drugs most commonly used within this population are diphenyihydantoin and phenobarbital. Each compound is reported to affect (albeit oppositely) the release of ADH, and both affect cellular enzyme systems related to water and/or electrolyte metabolism.