WASHINGTON — A key federal advisory panel declared Tuesday that nicotine is an addictive substance and concluded that the amounts of nicotine found in cigarettes now on the market could addict the "typical smoker," a finding expected to heavily influence an impending government decision to regulate cigarettes.
The Food and Drug Administration's drug abuse advisory committee said that the addiction is caused by the pharmacologic, or drug-like, effects of nicotine.
But it also said it believes there is likely a daily threshold of nicotine that could result in a psychological dependence, and also levels below which an addiction would be unlikely--although panel members said they were unable to determine the specific amounts.
The conclusions of the committee will almost certainly serve as the scientific underpinnings for the agency to act against cigarettes.
"This was a very significant finding," FDA Commissioner David A. Kessler said after the meeting. "It should change the debate. And it is a clear answer to the tobacco industry rhetoric about freedom of choice."
But tobacco company scientists disagreed with the conclusions of the panel. "The premise that nicotine in cigarettes is addictive at any level is incorrect," said Dr. John H. Robinson, a scientist at R.J. Reynolds Tobacco Co.
The FDA, which has regulatory authority over drugs, has methodically been building a case that cigarettes are, essentially, drug delivery systems, with nicotine as the drug. Agency officials believe they have the authority to regulate cigarettes if they can scientifically prove that nicotine is a drug and manufacturers have the ability to control the level of nicotine in cigarettes. One of the steps in the process was to ask the advice of its longstanding drug abuse committee, a panel of outside experts, to review the existing data and give its opinion.
Among the ideas under exploration by the agency is one that would require cigarette manufacturers to reduce nicotine levels gradually over a period of years to nonaddictive amounts. Experts believe this could help smokers wean themselves from their addiction and prevent young people who experiment with cigarettes from becoming addicted.
The panel heard scientist after scientist call nicotine addictive based on behavioral and other research. Many said that smokers lose control over their ability to stop smoking, which they said was a clear sign of drug dependence.
Also, many smokers suffer physical and psychological withdrawal symptoms, such as decreased heart rate, insomnia, irritability, difficulty concentrating and anxiety when they try to stop, they said.
"Cigarettes and other forms of tobacco are addicting, (and) nicotine is the drug in tobacco that causes addiction," said Dr. Richard D. Hurt, director of the Mayo Clinic nicotine dependence center.
Dr. David A. Gorelick, chief of the treatment branch of the National Institute on Drug Abuse's addiction research center, cited the results from a 1994 survey of 8,098 people. The survey showed that more than 30% had tried cigarettes at least six times in their lives, which Gorelick said was an indicator of dependence, compared with nearly 25% who had tried heroin six times in their lives, 15% for cocaine and 15% for alcohol.
"Looked at another way, the odds of dependence were greater for tobacco than for any other drug," he said.
Moreover, the drug-like and behavioral processes that determine tobacco addiction "are similar to those that determine addiction to drugs such as heroin and cocaine," he added.
Research conducted jointly by Dr. Jack Henningfield, chief of the clinical pharmacology research branch of the National Institute on Drug Abuse, and Dr. Neal Benowitz, professor of medicine at UC San Francisco, has suggested that there may be nonaddictive levels of nicotine in cigarettes.
A small percentage of the nation's smokers who smoke five or fewer cigarettes a day--individuals referred to by researchers as "chippers"--do not seem to become addicted, Benowitz said. Such smokers only take in about five milligrams of nicotine a day, he said.
Henningfield and Benowitz said that 10 to 20 milligrams a day generally is associated with nicotine dependence and withdrawal. Thus, a cigarette that delivers a maximum of .17 milligram of nicotine likely would not be addictive for an individual who smokes 30 cigarettes or fewer daily, Henningfield said.
But scientists representing the tobacco industry insisted that smoking is no more than a "habit" and that nicotine is no more addictive than caffeine.
Robinson said that "intoxification" is an "essential element" of addiction and that "smokers do not smoke to become intoxicated--and they do not experience withdrawal symptoms in any way comparable to those experienced by true addicts."
Also, smokers do not have to increase their amount of smoking over time to achieve the same effect, unlike those who use drugs such as heroin, he said.