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FURTHER ATTEMPTS TO BLOCK THE LSD REACTION BY PRETREATI-ENT WITH BOL (Experiments 56-D and 56-E).

Ginzel and Mayer-Gross reported that pretreatment with

3 mg. of BOL for one day attenuated the reaction caused by

40-50 mcgn. of LSD, and that two days pretreatment with 3 mg.

of BOL blocked it completely. Concoaitant administration of

BOL with LSD had no effect. In previous experiments, we were

able to confirm the latter finding but were,. however, unable

to confirm clearly attenuation of the LSD reaction by two

days pretreatment with BOL. In one experiment, ô subjects

received 1 mg. of BOL orally for two days, and an additional

milligram on the third day. Two hours after the third dose,

these 8 subjects were challenged with 1.0 to 1.5 mcgm./kg. of

LSD. A strong trend toward reduction of the intensity of the

LSD reaction was observed, but the reduction did not reach

statistically significant levels on any of the measures used.

The experiment wás not regarded as conclusive since 4 of the 8

subjects proved to be resistant to LSD. In a second experiment,

10 subjects received 3 mg. of BOL three times daily for thrae

days and an additional milligram on the fourth day. Two hours

after the last dose of BOL these patients were "challenged"

with 1.5 to 3.0 mcgm./kg. of LSD. Again a trend to reduction

in the LSD reaction was observed, which did not reach

B-3

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statistical significance. In this experiment, the partial

cross tolerance between 5OL and LSD may have. been obscured by

the relatively large dose of LSD used. Two further attempts

to block the LSD reaction with BOL have, therefore, been

carried out, using a dose or 1 mcgm./kg. or LSD, an amount .

comparable to that employed by Ginzel and fayer-Gross.

HETHODS

Subjects. Ali subjects were Negro male prisoners who

were serving sentences for violation of the Harrison narcotic

laws. All were abstinent from opiates for at least six months,

and all were in good physical and mental health. All except

2 of these had previous experience with LSD. In Experiment

56-D, 8 subjects were used; in Experiment 56-E, 10, subjects

were used; L patients served in both experiments.

Drugs. Were given oraliy in solution. In Experiment 56-D,

1 mg. of BOL tartrate was administered orally at 8 a.m., 4 p.m.,

and 10 p.m. for two days prior to challenge with. LSD. An

additional dose of 1 mg. of BOL was given two hours before (at

6 a.m.) on the day of challenge with LSD. An identical

schedule was used in Experiment 5ó-E, except that BOL was given

for five days prior to challenge with LSD instead of for three

days. In both experiments, the challenging dose or LSD was

1 mcgm./kg. given orally in soluticn to patients who were fasting.

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