FDA DRAFT GUIDELINES ON DRUG ABUSE TREATMENTS
FDA DRAFT GUIDELINES ON DRUG ABUSE TREATMENTS will be presented in final form to FDA's Drug Abuse Advisory Committee at its next meeting and then submitted to the agency for finalization and publication in the Federal Register, FDA consultant George Woody, MD, Department of Veterans Affairs Medical Center, Philadelphia, told a Feb. 27 meeting of the advisory committee. The first draft was circulated in January, Woody said, and a second draft, dated Feb. 12, was presented to the committee. The guidelines were drafted by a subcommittee of the Drug Abuse Advisory Committee, of which Woody was the chairman. The document, "Guidelines for the Development and Evaluation of Drugs for the Treatment of Psychoactive Substance Use Disorders," represents an effort by FDA to outline issues it considers important in the development of agents for treatment of drug abuse. Woody presented an update on the project at the last advisory committee meeting a year ago ("The Pink Sheet" Feb. 11, 1991, p. 9). The draft guidance has five sections including sections on preclinical studies, Phase I trials, Phase II/III trials and statistical considerations that will likely be an appendix, Woody said. In drafting the document, "we worked with an eye toward not being unusually onerous so as to slow down drug development," he added. One potentially burdensome but inescapable issue that "is in there several times," Woody said, is the need for sponsors to do drug interaction studies with the proposed agent and potentially abusable drugs. "Drug interaction studies are recommended, even in the case of pharmacotherapies that have been approved and are in general use for treatment of other conditions," the draft states. Such studies should include not only the "primary drug of abuse" but other drugs likely to be abused by the target population, the draft says. The draft guidelines outline six target areas for pharmacotherapy of drug abuse: substitution therapy, decrease of use of the target drug, prevention or delay of relapse, detoxification or withdrawal symptom treatment, reversal of toxic effects of abuse, and prevention of abuse in high risk populations. The targets of decreasing use of the abused drug and preventing abuse in high risk groups have been added since Woody discussed the project with the committee in 1991. The document identifies eight classes of abusable substances believed to be targets of pharmacotherapy: opioids; alcohol, other sedatives-hypnotics and anti-anxiety drugs; cocaine; amphetamines and other stimulants; tobacco; hallucinogens; marijuana; and phencyclidine (PCP). "These eight classes are obviously not the only substances of abuse," the draft states. "These guidelines are not intended to exclude studies on pharmacotherapies that may be helpful in treating problems that are associated with any substance of abuse. However, they focus on the classes which present the greatest current public health problems." Possible primary efficacy endpoints suggested in the draft include: drug use as measured by biological tests, self-reporting of use, measurement of money spent on drugs, or response to a challenge test; retention in therapy; physician or patient assessment of severity of dependence; and assessment of withdrawal symptoms or drug abuse toxicities. Secondary endpoints include: measurement of patient "craving" for the drug; psychiatric symptoms; illegal activities related to drug use; assessment of employment or family changes; substance abuse related mortality or morbidity. The majority of the draft document discusses clinical trial issues related specifically to each of the eight classes of abusable drugs. One element of consideration in all study designs, the document states, is the need to measure "the basic level of psychosocial services that are administered to patients in the trial," since any form of drug treatment will inevitably involve other interventions as well. FDA Pilot Drug Evaluation Staff Director John Harter, MD, presented a second draft document to the committee, "Draft Guidelines for Good Academic Research Practices in Animal Pharmacology," on the subject of preclinical abuse liability testing. Harter noted that it is unclear whether abuse liability testing is covered by Good Laboratory Practices regulations, and many institutions have balked at the possible added expense of coming into GLP compliance for such tests. The draft sets forth an alternative to GLPs which includes a certification checklist to assure FDA that the tests were properly conducted. Committee Chairman Theodore Cicero, PhD, Washington University School of Medicine, offered the committee's help in determining whether GLPs ought to apply to abuse liability testing. In the interim, he said he considers the draft "good common sense" guidance.
Sign in to continue reading.
New to Pink Sheet?
Start a free trial today!
Register for our free email digests: