ATTEMPTS TO  BLOCK LSD REACTION   V!l I TH BOL GIVE
                               S IMUL TANE OUS L Y '@XI I TH LSD
                  These experiments were   carried out  because the
            cl.ose chemical  similart-ty of SOL  and LSD  suggested   that
            SOL might block the LSD reaction     by competInSL  with  LSD
            for2 receptor sites.
                  Subjects  us2ed  were  15  nonfolerant  former  morphine
            addicts, all Negro males- who were t'n   good  physical   con-
            dition who presented no evidence of major psychoses.
            Most  of  these  patients  had  had  considerable  experience
            with  LSD.  They receivedi In rando.-.iized order, the
            following drug combinations:  SOL placebo plus LSD placebo;
            B2OL plus LSD; and BOL placebo plus LSD.  The combination
           ,of BOL plus LSD  placebo  was  not  studied  because  of  the
            shortage of BOL,  and  also  because  the  results  should  be
            identical wi,4h those described In the report dealing with
            the acute effects of SOL.
                  The do sage of SOL was '2-4  ma./10  ko.  of  bodywelobf
            and was give9n  with  the  LSD.  Nine  patients'  receive'd-the
            higher dose.    The dose of LSD was   0.5-1.5 mcg-,,n./kg.
            Smaller doses viere used'in the first pa@i@zntls tested.,
            because of the possibili@y @hat the drugs mighf synerglze.

                                                           2
               Methods.,  Measurements
                                        ncluded threshold for kne,,'erks
          PupillarY diameter, s                                    i    .9
                                y3folle blood pressurzj, th
                                                           e Abramson.
          Jarvik questio
                         nnalre
                                 and grading Of mental effects using
          the scale prev
                        lously described    The re
                                                  suits are shown in
          the table, a Copy of W
                                hich was sent with my
         8 March 1957.                                  eff er of
                         If is obvious 2that there wa'
                                                     's 'IO Significant
                                                    fuaflon of If,
         blocking of the LSD reaction'and no ae.cen
              Conclusion   Adm-tnisfratton of SOL si,-nultancously
         with LSD does not  block or accentuate th@e LSD reaction.
         Th.ere 2is no reason to believe that giving SOL after LSD
         would",give any different result$  since
                                          p       Ginzel and tviaye r-
        Gross have reported that Intravenous admi-nlsfraflon of SOL
        does not re verse the LSD reactions  These results suggest
        that the attenuation of the LSD reaction observed a  ffer
        fw,o d4ays pre-freafmenf with LSD is due to the development
        of cross folzrance.