It wasn't quite the same as a chummy chat over cocktails or a tete-a-tete in the White House mess, but for two hours yesterday representatives of consumer groups got a chance to bend an important Reagan administration ear.

"It's not that easy to talk to the commissioner these days," said Dr. Bambi Young of the Center for Science in the Public Interest, one of more than 60 representatives of consumer and women's groups who filled the auditorium of the Hubert H. Humphrey Building for a session with Food and Drug Administration chief Arthur Hull Hayes Jr.

Hayes, flanked by Deputy Commissioner Mark Novitch and Associate Commissioner Alexander Grant, was presiding over a National Consumer Exchange meeting, a ritualistic gathering of top FDA officials and some of their most frequent critics, consumer advocacy groups.

FDA has offered the public meetings since 1978 as a way to give consumers a chance to ask questions, express viewpoints and disagree with top policy-makers. There weren't any rank-and-file consumers at yesterday's meeting, and any who wandered in off the street might have found the conversation about orphan drugs, beta blockers and adverse drug effect surveillance a mite on the esoteric side.

But the special-interest groups were there in force, ranging from the Nader-backed Public Citizen Health Research Group to the Gray Panthers, and more than a dozen industry representatives came along to monitor the action.

The sparring was relatively gentle, but some of the participants hoped they had landed a punch or two where it counted.

Young, for example, chided Hayes and Novitch for the agency's approval of over-the-counter diet aids containing phenylpropanolamine, a drug suspected of causing or aggravating high blood pressure.

"Hayes is a hypertension man," Young said later, referring to the commissioner's widely known interest in the subject. She acknowledged that her points already had been made in formal comments to the agency, but "Hayes is never going to read those -- it'll be some underling, some way, way underling."

Marcia Greenberger of the National Women's Law Center, who presented the case against FDA's recently proposed streamlining of the drug approval process, agreed that the face-to-face sessions are valuable.

"It is a useful thing for groups that don't always have the access that industry has," she said. "It's often true that the way decision-makers make choices is not by written comment but by meetings. The information isn't always new, but decision-makers see how vehemently the public feels about the issue."

The closest the group got to vehemence yesterday, however, was over an old emotional issue -- laetrile, the controversial cancer treatment drug that is banned in this country on the grounds that it is ineffective.

In its Oct. 19 proposals for speeding up new drug approvals, FDA slipped in what some of the participants yesterday saw as a ringer: a "miscellaneous" regulation that would permit the import "for personal use" of an "unapproved new drug product or an uncertified antiobiotic drug product" not governed by the Controlled Substances Act.

"Is this a laetrile exemption that doesn't apply to pot?" asked one participant.

Hayes responded that the provision was included in response to consumer complaints, and in an effort to make the agency "a little less Big Brotherish."

Bill Schultz of the Public Citizen Litigation Group told Hayes he found the move "disappointing" and "unfair to those who can't afford to travel abroad."

"If FDA thinks it's a good idea," Schultz suggested, "let them take it to Congress for a full debate."