It must be frustrating to be Bolivian narcotics agent.

Trained and equipped by the United States, the agents have arrested more than 300 suspects since 1973 when Bolivia enacted a tough drug law drafted with the help of the United States.

Now U.S. diplomats in Bolivia have been working for the release of some of those suspect, young Americans held for months or years without formal sentencing.

American and Bolivian officials say they see not inconsistency, but it shows why Latin Americans become irritated with the changing polices and diplomatic styles of their northern neighbor.

The story began in 1973 when strict drug control laws were being pushed by the Nixon administration. A Justice Department lawyer was sent to Bolivia to assist a Bolivian commission in drafting the country's first drug law.

The United States also paid the salaries of some commission members, according to a State Department official.

The law the commission drafted was unusually harsh, according to U.S. and Bolivian officials. It called for minimum penalties of 10 years for possession of drugs and 20 years for trafficking.

With $585,000 worth of U.S. aid, Bolivia's narcotics agents began rounding up people they thought to be drug traffickers. In the process, they picked up about 35 Americans, most of them in their 20s and 30s.

According to relatives of the jailed Americans and State Department officials, some of the Americans caught in the dragnet were casual drug users or innocent bystanders.

Few of the Americans have been sentenced. Their trials have dragged on partly because Bolivian court dockets are clogged and partly because judges are hesitant about sentencing the Americans.

One judge, who dismissed a case in which there appeared to be overwhelming evidence against the defendant, was tried and sentenced to jail for malfeasance. Other judges reportedly are reluctant to hand down the long sentences required by the 1973 law.

Under pressure from relatives of the jailed Americans and their congressmen, the State Department stepped into the case.

A three man team headed by career diplomat Sam Moskowitz was sent this month to Bolivia to talk to the prisoners and see if their trials could be speeded up. They met with a group of Bolivian judges and with Interior Minister Col. Juan Pereda.

State Department legal officer Louis G. Fields, a member of the team, said Pereda told him there would be a case-by-case review "to see if there is a sufficiency of evidence" against the Americans.Fields said that in his opinion there was not enough evidence against some of the defendants "to satisfy our legal system."

Fields said that "as far as we're concerned," the review "shouldn't take more than a month."

In the meantime, Bolivia, apparently with no help from the United States, has enacted a new drug control law. Efforts are also being made to speed up the trials of drug defendants.

Fields said he did not think the State Department's efforts to help the jailed Americans contradicted the U.S. policy of encouraging efficient action against drug traffick.

"We want justice done," he said. "And we want to keep a cooperating government interested in continuing cooperation. I think the Bolivians are sympathetic to that."