Cocaine-Related Deaths Decline for First Time in a Decade, Federal Figures Reveal : Drugs: Reports from medical examiners also show a 47% plunge in the last quarter of 1989. The statistics do not include data from Los Angeles.

The number of cocaine-related deaths in America declined in 1989 for the first time in at least a decade, falling 26% largely because of a precipitous plunge in the final three months of the year, according to medical examiner reports from around the country.

The decline from 1988, based on preliminary data submitted to the National Institute on Drug Abuse, reverses a dizzying upward spiral in which the number of cocaine-related deaths more than tripled over the three previous years.

The national statistics show that the number of cocaine-related deaths plunged by an extraordinary 47% during the final three months of 1989 compared to the previous quarter. The drop exceeded a previously reported 22% decline in cocaine-related medical emergencies reported by hospitals in the same period.

Taken together, the findings add credence to arguments that cocaine use throughout the United States may have peaked--even among addicts whose habitual drug use makes them most vulnerable to death or injury.

Some hospital officials, however, suggested instead that the same number of users could be consuming less potent forms of the drug. Evidence of a decline in cocaine purity has so far been inconclusive.

The new figures on cocaine deaths, collected by the federal government as part of its Drug Abuse Warning Network, do not include data from Los Angeles, where medical examiners were late in submitting their reports. The findings, made available to The Times, are expected to be made public next week.

The reports, from 24 cities, list the number of times that cocaine or other drugs are mentioned by medical examiners as the principal or contributing cause of death, including overdoses, accidents and violence. The provisional numbers show 2,649 cocaine-related deaths in 1989, down from 3,561 the year before.

The rate had remained largely steady for the first nine months of 1989, then plummeted in the final quarter, dropping from 756 cocaine deaths in the July-September period to just 404 such deaths from October to the end of the year.

That fourth-quarter plunge mirrored the pattern in cocaine-related emergencies reported by hospitals around the country. The change was hailed by Health and Human Services Secretary Louis W. Sullivan as an indication that “we are making significant headway in our efforts to establish a drug-free America.”

Rep. Charles B. Rangel (D-N.Y.), chairman of the House Select Committee on Narcotics Abuse and Control, has expressed skepticism that drug abuse is declining. He charged in an interview last week that many victims of cocaine abuse were suffering and dying in the streets and thus were not included in hospital and emergency room statistics.

According to the medical examiner reports, the most dramatic fourth-quarter decline in cocaine deaths occurred in New York City, which represents about one-third of the Drug Abuse Warning Network figures. The annual total dropped from 1,309 in 1988 to 969 in 1989--a 26% decline--while the fourth-quarter rate plunged 58%.

New York began to submit its reports to the federal government in 1988, and for that reason will not be included in this week’s warning network analysis of longer-term trends. Without New York, the number of cocaine deaths recorded dropped 25% last year, from 2,252 to 1,690. The drop for the final three months of the year was 40% without New York’s figures included.

The longer-term analysis by the warning network, which excludes New York, shows that the number of cocaine-related deaths more than tripled between 1985 and 1988, leaping from 717 to 2,252.

In addition to the reversal in cocaine figures, the 1989 data also shows a significant annual plunge in all drug-related deaths.

With Los Angeles not yet reporting, the figures show a 28% reduction in the number of deaths in which any drug was listed as a contributing factor, with an equal drop in heroin-related deaths.

The National Institute on Drug Abuse has noted in the past that its provisional figures remain subject to change, and cautioned that data for individual cities, particularly for a single quarter, may not be reliable.

But the institute previously has described the medical examiners’ report as providing an important indicator of broad national trends in drug abuse.