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ATTEMPTS TO BLOCK LSD REACTION WITH BOL GIVEN SIMULTANEOUSLY WITH LSD

These experlments were carrled out because the close chemlcal similarlty of BOL and LSD suggested that BOL mlght block the LSD reactlon by competing wIth LSD for receptor sltes.

Subjects used were 15 nontolerant former morphine addicts, all Negro males who were In good physical conditlon who presented no evidence of major psychases. Most of these patlents had had consIderable experlence. with LSD. They recelved, In randomized order, the following drug combinatlons: BOL placebo plus LSD placebo; BOL 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 Idenfical with those described in the report deallng wlth the acute effects of BOL.

The dosage of BOL was 2-4 mg./70 kg. of bodyweight and was given wlth the LSD. Nine patients received the higher dose. The dose of.LSD was 0.5-l.5 mcgm./kg. Smaller doses were used'in the first patlents tested, because of the posslbllity that the drugs might synergize.

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Methods: Measurements Included threshold for kneejerks, puplllary diameter, systolic blood pressure, the Abramsonlarvik questlonnaire, and grading of mental effects uslng the scale prevlously described. The results are shown in the table, a copy of which was sent with my letter of 8 March l957. It is obvious that there was no slgnlficant blocking of the LSD reactlon and no accentuation of it.

Cancluslon. Administration of BOL simultaneously wlth LSD does not block or accentuate the LSD reaction. There Is no reason to believe thet giving BOL after LSD would'give any different results, slnce Ginzel and Mayer-Gross have reported that Intravenous administratlon of BOL does not reverse the LSD reactlon. These results suggest that the attenuatlon of the LSD reactlon observed after two days pre-treatment with LSD is due to the development of cross tolerance.

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Discusslon. Because of the inconclusiveness of eA the experiment It wlll have to be reperted. Fortunately wz haye succeeded in obtalning an additlonal supply of Bol and will repeat the experlment using a larger number of subjects, all of whom will be tested with LSD prior to Inltiatlon of the formal experiment in order to eltminate nonreactors or fo establlsh a dosage whlch will create a signiflcant degree of reaction. We Intend to glve BOL for three days prior to LSD, two days prior to LSD, and to do another experlment in which a single dose will be given two hours before the LSD.