Cocaine Vaccines Not Effective or Long Lasting Enough
Another study finds heroin addicts respond better to implants than oral naltrexone
WEDNESDAY, Oct. 7 (HealthDay News) -- Cocaine vaccination is only effective in a minority of patients and the effect is not sustained, according to a study published in the October issue of the Archives of General Psychiatry, while a second study finds that naltrexone implants are more effective than oral doses of the drug in treating heroin addiction.
Bridget A. Martell, M.D., of Yale University School of Medicine in New Haven, Conn., and colleagues conducted a randomized controlled trial of 115 methadone-maintained cocaine- and opioid-dependent people, and found that 38 percent of those given five vaccinations of succinylnorcocaine attained IgC anti-cocaine antibody levels of at least 43 µg/mL. These subjects had a significant reduction in cocaine use, but the effect lasted only two months.
Gary K. Hulse, Ph.D., of the University of Western Australia in Nedlands, and colleagues conducted a six-month study of 70 heroin addicts who received oral naltrexone and placebo implants for six months, or a naltrexone implant plus placebo tablets, and found that fewer subjects in the implant group had returned to regular heroin use after six months, compared to those in the oral naltrexone group.
"This sustained-release implant is effective in retaining previously opioid (heroin)-dependent patients in treatment and that efficacy is improved compared with oral naltrexone," Hulse and colleagues conclude. "Therefore, sustained-release naltrexone implants appear to provide a new treatment option for patients with heroin dependence, particularly for those seeking an alternative to opioid agonist maintenance."
The first study was supported by Celtic Pharmaceuticals. Martell is a medical director at Pfizer Inc.