Medical researchers are no more averse to fads than the rest of us.

When a promising (scientific) thing comes along, researchers break their necks to outdo one another in discoveries along the new lines, be it a new class of drugs, new functions for old substances, new substances for old functions. . . .

A couple of decades ago was the Era of the Hormone. Cortisone was king, and steroids -- promised the researchers -- would be the answer to just about everything, from rheumatoid arthritis (where they helped a lot), to eternal youth, especially for women (where they didn't work so well.)

That it didn't pan out that way is no criticism of research or researcher. A biochemical fad is not akin to swallowing goldfish, except in its currency. And it is the rare discovery that does not lead to a host of others.

Pharmacologists have been predicting for some years that the '80s would be the Decade of the Prostagladin and corroborating research is accumulating. b

Scientists are far from knowing exactly what prostaglandins are, and precisely what they do, but they know that there are many cases in which inhibiting them often can cause pain to be eliminated.

This whole new approach to pain control is beginning to explode in a number of new anti-pain drugs which probably will have side effects no greater than those of aspirin, be much more powerful -- in strength and lasting effect -- and, best of all, promise to be more resistant to abuse or addiction, psychological and physiological. (Doctors, or course, remember with some skepticism that heroin, for example, as well as Darvon, were introduced with the same promise.)

Dr. William Beaver, pharmacology professor at Georgetown University Medical School, has conducted some of the clinical trials and believes that the new analgesics will live up to their promises. "Now we really do have something better than aspirin," he says, "that isn't a narcotic."

One of the drugs Dr. Beaver has studied is Zomax, a newly approved prescription drug manufactured by McNeil Laboratories. Zomax is as strong as many narcotics, but is tolerated as well as, and in some cases even better than aspirin. McNeil expects it to be useful in treating low back pain, muscle and joint pain, headaches, toothaches, sprains, fractures and post-surgical pain.

Another recently approved drug of this class is Anaprox, produced by Syntex especially for use in dysmenorrhea.

And a number of other similar drugs are in late stages of clinical trails, or about to be approved. Some already are used in other countries. One, Dolobid (a Merck compound), shows particular promise in pain caused by dental or periodontal surgery. It is, says Dr. Beaver, one of the longest-acting drugs he has ever seen, although it may not have the strength of some of the others.

However, says Beaver, "I think it's great that there will be a whole bunch of these. For such a long time we were so limited in what we could prescribe. oBut if you've got two dozen good drugs out there, you can play with the dose a little. If one doesn't work, you can say, 'Don't panic, we've got a lot of things we can try.'"

Scientists know that prostaglandins are natural fatty substances -- akin to hormones -- but found in numerous forms in virtually every cell of the body. Among other still-hidden functions, they seem to be the alarm-bell ringers when some part of the body needs attention. If there is an injury, for example, it is now thought that prostaglandins will flood the area, causing inflammation and pain so that the whole organism will favor the injured area and permit it to heal.

It is as though the prostaglandins (figuratively) hop up and down and shriek that your cut finger hurts, and indeed, make certain that it does.

It is prostaglandins that often are the culprits in disabling dysmenorrhea. They cause uterine spasms and play a prominent role in birth labor. But in some women, too many are manufactured during menstruation. Not only do they cause severe cramps, but they overflow into the system as a whole -- which is why dysmenorrhea is so often associated with dizziness, nausea, headaches and, to borrow a Gilbertian understatement, a general sense that you haven't been sleeping in clover.

Prostaglandins do a lot of other things, too, like protect against stomach and intestinal ulcers and inflammation, and regulate blood pressure. They can induce labor -- and, tests now show, can be made to induce abortions, apparently more safely and easily than many other popular techniques.

Prostaglandins don't last long, only, apparently, long enough to do a small, specific job, depending on where they are made. Usually they are well-behaving, essential parts of the human physiology. Sometimes, however, they become, you might say, overenthusiastic.

The race for new prostaglandin (and therefore pain) inhibitors came about almost by accident -- the case in so many scientific advances. It was discovered that a lot of the anti-inflammatory and analgesic effect of asprin was due to its mild interference with the manufacture of prostaglandins.

Then, in 1974, prostaglandins were linked to dysmenorrhea. Some physicians, including New York's Dr. Penny Budoff (who disbelieved the conventional wisdom that dysmenorrhea was mainly a psychological problem) started trails of prostaglandin inhibitors in women with disabling dysmenorrhea. The remarkable success led to FDA approval of several drugs for dysmenorrhea, drugs that already were on the market (by prescription) for arthritis -- notably Motrin and Ponstel.

More importantly was the resulting general medical acceptance of dysmenorrhea as a bona fide biochemical, rather than a psychological, condition, a reversal of enormous proportions accomplished virtually overnight. c

A complete re-examination of prostaglandin-inhibiting arthritis drugs followed, for possible broader application, and the research for new and better ones was intensified.

The possibilities apparently are endless. Physicians do not always know why, but as chemically similar as humans are, individual reactions are unique, and one easily can translate "one man's meat . . ." into "one human's prostaglandin inhibitor . . .