Along with baseball, rock music and beef, Western-style drugs have found a treasured place in Japanese life over the past 20 years. At a rate increasing faster than in any other country, patients flock to doctors' offices and hospitals for tonics, vitamins, antibiotics and other prescriptions.

In a halting and so far ineffectual way, the government is trying to limit the drug use, much of which is unnecessary in the opinion of medical experts. They say doctors' bank accounts are the big beneficiaries.

The experts agree that much of the rapid increase is due to a Japanese penchant for taking drugs for minor ailments, often imaginary.

Japanese turn to expensive medicine, says Dr. Akira Sakuma, "just when they feel fatigued and kind of subhealthy. In the morning, they may feel tired on the train and decided that some kind of vitamin may be good for them."

he says the habit is encouraged by the practice of doctors who make the money prescribing pills under the country's health insurance system.

"The doctor gets no money if he just tells a patient to go home and get some sleep and eat well," says Sakuma, of the Tokyo Msdical and Dental University's Medical Research Institute.

The president of Japan's powerful Medical Association , Dr. Taro Takemi, insists that Japanese are no more drug-prone than patients in other countries and argues that a current government attempt to change the pill peddling system will mean poorer health care for many ill persons, especially the poor.

According to Sakuma's statistics, Japan ranks with the United States and France as the highest drug-consuming countries in terms of personal expenditures. What is more revealing is the rapid increase here in recent years. The rate of increase is far greater than in any other country measured. Sakuma also says, that while in six other countries less than 1 percent of the net national product is spent for drugs, in Japan it is 1.7 percent.

(In 1972, the last year for which figures are available, Japanese spent 3.7 billion for medicinal drugs.)

Much of the blame is placed on the national health insurance system, which since 1961 has covered about 95 percent of the population. It pays for virtually every drug and medicine prescribed.

The common pratice is for doctors to dispense the medicines to patients in their offices, later collecting their reimbursement from the government at rates based on a list of standard prices.

Doctors are able to purchase most drugs from wholesalers at prices far below the government's list prices - an average of 27 percent below, according to a survey conducted by the Yomiuri newspapers. One tranquilizer, the survey found was bought by doctors at a price of 94 percent less than that which could be charged to the patient. Critics contend this substantial profits for doctors and private hospitals is an inducement to prescribe freely and often.

Other studies have uncovered striking abuses. One hospitals was found to be charging the insurance system for drug treatment of a man three months after he had died. Another man was listed as being medicated at one hospital when he actually was bed-ridden in another one.

The critique of prescription profits has come at a time when Japan's doctors are already being accused of making too much of drugs, they also benefit from a n enormous tax break. Stories of their high incomes are frequently headline news.

A member of the parliament's upper house made a detailed study of physicians incomes listed in tax returns and found that in 18 out of 47 prefectures, a doctor had earned more money than anyone else last year. Part of the reason, his study concluded, was the profit from prescriptions.

The survey placed the average earnings of physicians within the medical insurance system at $55.254, four and a half times the average annual income of all salaried workers, and one doctor was found to have earned $2.2 million one year.

Other prominent researchers have charged that doctors are passing out drugs they know little about. Dr. Kosei Takahashi, of Tokyo University, has denounced the practice of prescribing dubious drugs for minor illnesses and calls doctors little more than "salesmen for pharmaceutical companies."

The Health and Welfare Ministry has proposed a law that would require patients to pay at least half the cost of drugs. It believes that those not seriously ill would resist accepting doctors' prescriptions if the money came out of their own pockets instead of from the insurance fund.

The Japan Medical Association is opposed to the bill and its president, Dr. Takemi, said in an interview that he has the assurance of the ruling Liberal Democratic Party that it will be withdrawn. Dr. Takemi said that requiring patients to pay for half of the cost of drugs would discourage many poor persons from seeking needed medical care.

Takemi said he favors revising the health insurance law to diminish the gap in health care available for rich and poor. But he contended the ministry's proposal would have the opposite effect.