The reported occurrence of false-positive results of pregnancy tests in patients taking certain tranquilizers has been investigated. The test in question involved the intra-abdominal injection of a urine concentrate from the patient into male frogs, and the production of spermaturia constituted a positive result. The 50 psychiatric patients in the present study were all receiving promazine, prochlorperazine, or perphenazine daily in substantial doses. Samples of serum were obtained for use in place of urine concentrates. Hyaluronidase was injected with the serum to facilitate adsorption. Two frogs weighing from 25 to 50 Gm. were used for each of the 50 tests. There was no evidence that the test carried out in this way would give false-positive results in patients receiving tranquilizers of the phenothiazine group.
JAMA – American Medical Association
Published: Aug 15, 1959