Cocaine use among the District's criminal defendants has risen sharply in recent months, reflecting what authorities said is an alarming increase in use of the drug nationwide, according to figures released yesterday.

"In societal terms, the significance of this kind of use is staggering," U.S. Attorney Joseph E. diGenova said. "It's a very, very dangerous situation."

The number of defendants who tested positively at D.C. Superior Court for cocaine use has increased from 14 percent to 22 percent in the last five months, while PCP use has dropped sharply, city bail officials said.

While the drug-testing results may reflect fluctuations in police enforcement tactics, some authorities said the figures could signal the emergence of cocaine as the illicit drug of choice in the city.

Police said cocaine is now more available than ever and in purer form, although street prices for the drug have remained about the same, about $90 to $100 a gram.

"Three or four years ago we had very few cocaine arrests," said Sgt. Dean Hyde of the police department's narcotics division. "Now it's an everyday thing."

The test results released yesterday are part of an ongoing program in the city's court begun in March to examine how drug use affects criminal behavior. Defendants held in the court's cellblock before arraignment are required to give a urine sample that is tested for traces of drugs, including heroin, PCP and cocaine.

According to figures released by the D.C. Pretrial Services agency, nearly 10,000 defendants have been tested and 53 percent have shown signs of drug use. Cocaine use hovered around 15 percent in March, then rose to 18 percent in June and dipped to 14 percent in July.

In the last five months, however, the percentage showing signs of cocaine use has risen steadily to 22 percent.

"I really don't know what it means," said agency director John Carver. "I think what's important is that there's been a steady upward trend since July and that there's a similar trend in New York."

Eric Wish, a national authority on the relationship between crime and drug use, said, "What you may be seeing is the first indication of an upturn in other things," such as hospital admissions for drug overdoses.

Others see the increased detection of cocaine among those arrested as a further sign that the drug is proliferating in all strata of society. "There's mounting evidence that cocaine use is increasing everywhere," said Mary A. Toborg, a research consultant to the National Institute of Justice.

Federal law enforcement officials have expressed mounting concern about the the record flow of cocaine across U.S. borders and its rising sales around the country.

In hearings before the President's Commission on Crime last month, experts testified that an increasing number of Americans in all social classes are using cocaine, becoming addicted to it, and in some cases dying from overdoses.

Similar drug testing in New York City showed that more than 40 percent of defendants examined had recently used the drug, Wish said.

The number of defendants who showed signs of PCP use, which peaked at 35 percent in May, has dropped since September to less than 30 percent, according to the test results. Heroin use has hovered around 20 percent.

Authorities said they are concerned about the rising use of cocaine because they believe users are unaware of a growing body of evidence showing that the drug can have harmful side effects.

One California researcher who previously issued widely publicized findings that cocaine is harmless recently reversed himself, saying half of cocaine users run the risk of becoming dependent on the drug and that he regards cocaine now as potentially lethal.

Wish said data from New York suggest that cocaine in many cases is a "starter" drug and that many users begin to combine it with opiates, such as heroin. "The problem is that there really is no good treatment program for cocaine," Wish said.