Cocaine-specific antibodies blunt the subjective effects of smoked cocaine in humans.
BACKGROUND
Rates of relapse among cocaine-dependent patients are high, and new treatment approaches are needed. Clinical data demonstrate that a cocaine vaccine (TA-CD) produces selective anticocaine antibodies, yet the impact of these antibodies on cocaine's direct effects is unknown. The objective of this human laboratory study was to measure the relationship between antibody titers and the effects of smoked cocaine on ratings of intoxication, craving, and cardiovascular effects.


METHODS
Ten cocaine-dependent men not seeking drug treatment spent 2 nights per week for 13 weeks inpatient where the effects of cocaine (0 mg, 25 mg, 50 mg) were determined before vaccination and at weekly intervals thereafter. Two doses of TA-CD (82 microg, n = 4; 360 microg, n = 6) were administered at weeks 1, 3, 5, and 9.


RESULTS
Peak plasma antibody levels, which were highly variable, significantly predicted cocaine's effects. Those individuals in the upper half of antibody production had an immediate (within 4 minutes of cocaine smoking) and robust (55%-81%) reduction in ratings of good drug effect and cocaine quality, while those in the lower half showed only a nonsignificant attenuation (6%-26%). Self-reported cocaine use while participants were outpatient tended to decrease as a function of antibody titer (p < .12). By contrast, higher antibody levels predicted significantly greater cocaine-induced tachycardia.


CONCLUSIONS
The TA-CD vaccine substantially decreased smoked cocaine's intoxicating effects in those generating sufficient antibody. These data support further testing of cocaine immunotherapy as a treatment for cocaine dependence.
College of Physicians and Surgeons of Columbia University, New York, New York, USA. mh235@columbia.edu
Margaret
M
Haney
Erik W
EW
Gunderson
Huiping
H
Jiang
Eric D
ED
Collins
Richard W
RW
Foltin
D000328:Adult; D000906:Antibodies / Q000097:blood / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D003042:Cocaine / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D019970:Cocaine-Related Disorders / Q000097:blood / Q000276:immunology / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D010147:Pain Measurement; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors; D014611:Vaccination / Q000379:methods*
D000906:Antibodies; D003042:Cocaine