The United States, responding to an appeal from several multinational drug companies, has asked Bangladesh to reconsider a new national policy designed to ban hundreds of drugs that it says are ineffective, dangerous or too expensive.

Among the drugs Bangladesh wants to ban are several that are not permitted in the United States, including clioquinol, a chemical that is known to cause serious damage to the nervous system. More than 70 percent of the drugs on the list have been described by the Food and Drug Administration or its British counterpart as therapeutically worthless.

A spokesman for the State Department acknowledged yesterday that the Pharmaceutical Manufacturers Association (PMA), a trade organization for the drug industry, asked it to bring pressure on the Bangladesh government to delay implementing the law pending discussions with the manufacturers.

"The State Department has a statutory responsibility for assisting American interests abroad," the spokesman said. "In this particular case, the U.S. government is also concerned that these regulations may inhibit future foreign investment in Bangladesh."

But the U.S. action has been condemned by several international and U.S. charity and consumer groups. "Encouraging this review is certainly not helping the people of Bangladesh," said a spokesman for War on Want in London yesterday.

The Washington-based Public Citizen Health Research Group, in a letter addressed to Secretary of State George P. Shultz, called the action "unconscionable."

"Perhaps you are unaware that many of the U.S.-based multinational drug companies are foisting on innocent people in the developing countries drugs which our own medical authorities consider worthless and unnecessary," the letter said.

The group expressed dismay that the State Department had allowed itself "to be used by the giant multinational drug companies to promote and protect their exploitation of the impoverished citizens of undeveloped countries."

The law, which was announced by the Bangladesh military government in June, prohibited the future sale of more than 1,700 drugs and immediately banned 237 products which were considered dangerous. Among the American drugs mentioned were products made by Merck, Pfizer, Searle, Squibb and Upjohn.

According to the members of the committee that drew up the new policy, eight multinational companies, including the American companies Pfizer and Squibb, shared 75 percent of Bangladesh's $100-million-a-year drug market. Pfizer dominated the market with more than $10 million in sales in 1981, while Squibb sold around $5 million in the same year.

Nineteen Pfizer drugs appeared on the list of drugs to be banned immediately, including its Stericol capsules, which contain clioquinol. Among the 22 Squibb products listed were Quixaline tablets and Suspension, both of which also contain clioquinol. Neither Pfizer nor Squibb would comment on the new law or the drugs named in it.

A spokesman for the pharmaceutical association, which led a delegation representing the drug companies on a recent week-long trip to Bangladesh to make the industry's views known, described the new law as "precipitous" and prejudicial to public health.

PMA argues that blocking the flow of drugs from its member companies could open the market in Bangladesh to uncertified and potentially impure drugs from other sources.

Bangladesh is the third-poorest country in the world, according to statistics from the World Bank, with the lowest per capita income, the lowest life expectancy and the highest infant mortality of all the developing countries. Approximately 60 percent of the country's health budget is devoted to the purchase of drugs, compared to less than 10 percent in the United States.

Because of that, Bangladesh is eager to bring its drug outlays under control, and to begin to produce some of the less complex, common drugs domestically.

The Bangladesh committee acknowledged "with appreciation" the role of the multinationals, but urged them to devote their "machinery and technical know-how" to producing important and innovative drugs and leave the production of simple and cheap drugs to the domestic companies.

Worldwide drug sales to the developing countries exceed $30 billion a year, however, and the multinational drug companies fear that other developing countries will follow Bangladesh's example.

The economics attache at the Bangladesh Embassy in Washington said of the new law, "I think it is a very good step forward." But he said the review requested by the State Department was normal and "not important."