A RAPID, SEMI-QUANTITATIVE URINE COLOR TEST FOR PIPEBAZINE-LINKED PHENOTHIAZINE DRUGS (COMPAZINE, TRILAFON AND ANALOGUOUS COMPOUNDS)

A specific urine color test for the piperazine-linked phenothiazine drugs (Compazine, Trilafon, Dartal, Stelazine, Prolixin, etc.) is reported, in which 1 ml. of urine is mixed with 1 ml. 10% trichloracetic acid. To this mixture 1 ml. of 1/1000 molar solution of mercuric nitrate in concentrated hydrochloric acid is added. The resulting color is read within 30 seconds against a color chart showing 4 color intensities, marked from (+) to (++++), for daily drug doses from 10 to 125 mg. The test is suitable for semi-quantitative determination of Stelazine and Prolixin for the first few weeks of administration only, and thereafter should be used as a qualitative test.

No false negative tests were encountered in over 3000 urine specimens. Two percent false positive tests seen in control specimens are tentatively ascribed to bile metabolites arising from impaired liver function. Potential errors in the interpretation of these tests in case of simultaneous or previous intake of other phenothiazine drugs are discussed.