The manufacturer of Tylenol offered yesterday to let all stores and consumers return Tylenol capsules, both regular and extra strength, to be exchanged for tablets of the medication at the company's expense.

When returned, "all the product will be destroyed," said Robert Kniffin, a spokesman for the company, McNeil Consumer Products Co.

More than 22 million bottles of Tylenol containing several hundred million capsules are in the hands of stores or consumers. Kniffen said the value of the product to be destroyed has not been estimated but would be in the tens of millions of dollars.

Those who send full or partially full bottles to the exchange center will receive tablets in return, and postage both ways will be paid by the company.

Bottles of Tylenol capsules should be sent to Tylenol Exchange, P.O. Box 2000, Maple Plain, Minn., 55438, or, the bottles may be exchanged at the store from which they were purchased.

Kniffin said it has not been decided whether Tylenol capsules will ever be offered for sale again.

He said the decision to exchange tablets for capsules came as a follow-up to the Food and Drug Administration announcement, supported by the company, that consumers should not take any Tylenol capsules.

Seven people died in Chicago last week after taking cyanide-loaded capsules of "Extra-Strength Tylenol."

Reports of Tylenol-related illnesses have flooded public health agencies since last week, but by yesterday most appeared unfounded. Investigations into the Chicago deaths were continuing, but with a diminishing number of leads.

Chicago's top police official yesterday ruled out a link between a Philadelphia student's death by cyanide in April and the seven Chicago deaths.

"Based on the preliminary report from Philadelphia police , with the facts we know now, the cases are not connected," said Police Superintendent Richard Brzeczek.

The investigation of graduate student William Pascual's death, originally ruled a suicide, was reopened Tuesday after the Chicago deaths.

Investigators discovered that a bottle of "Extra-Strength Tylenol" capsules found in Pascual's apartment contained cyanide, a piece of evidence that was not detected in the initial investigation.

Pascual had left what police characterized as a suicide note. He had emptied all of his bank accounts before he died.

Last April, the Philadelphia medical examiner said Pascual died from ingesting cyanide, which was found in his stomach and blood.

Frank Scafidi, chief of the Philadelphia police homicide division, said it is not known if Pascual had ingested any of the "Extra-Strength Tylenol" capsules from the bottle.

Philadelphia police said their investigation was in the early stages and cast no new light on the mystery yesterday.

In Oroville, Calif., detectives said an earlier Tylenol related episode -- the possible strychnine poisoning of 27-year-old butcher Greg Blagg -- was probably a purely local incident, and state officials turned over the investigation to local police.

Blagg said he became ill Sept. 30 after taking "Extra-Strength Tylenol" found to be tainted with strychnine.

A truck driver in Memphis whose body was found in his rig next to some Tylenol capsules earlier this week was found yesterday after an autopsy to have died of coronary artery disease.

No poison was found in his body or in the Tylenol.

Similarly, a woman found dead in Wichita, Kan., with Tylenol nearby was found after an autopsy to have died of heart failure. Neither her body nor the Tylenol bottle were found to contain any poison.