I'm sorry, but you seem to have your facts backwards

The facts of the case are this: Lee died after falling into a coma. The coroner's report was inconclusive, and medical authorities came up with five reasons for Lee's untimely death. However, they all agreed that it was caused by a cerebral edema (a swelling of the brain caused by a congestion of fluid). But what caused the edema became a matter of speculation. For the most part, the course of events on that fateful July day in 1973 can be pieced together. According to Lee's wife, Linda, Bruce met film producer Raymond Chow at 2 p.m. at home to discuss the making of Game of Death. They worked until 4 p.m., and then drove together to the home of Betty Tingpei, a Taiwanese actress who was to also have a leading role in the film. The three went over the script at Tingpei's home, and then Chow left to attend a dinner meeting.

A short time later, Lee complained of a headache and Tingpei gave him a tablet of Equagesic—a kind of super sapirin. Apart from that, Lee reportedly consumed nothing but a couple of soft drinks.

At around 7:30 p.m., Lee lay down for a nap and was still asleep when Chow called to ask why he and Tingpei had not yet shown up for dinner as planned. The actress told Chow she could not wake Lee. The ensuing autopsy found traces of cannabis in Lee's stomach, but the significance of this discovery is debatable. Some believe the cannabis caused a chemical reaction that led to the cerebral edema, but the coroner's inquiry refutes this theory. In fact, one doctor was quoted as saying that the cannabis being in Lee's stomach was "no more significant than if Bruce had drunk a cup of tea that day."
source: http://www.allbrucelee.com/article/mystery_of_bruce_lee.htm

What caused the cerebral edema in the first place may be up for discussion, although a certain Dr. R. R. Lycette of the Queen Elizabeth noted his (read: Bruce Lee) death as a consequence to a hypersensitivity of one or several of the compounds of the Equagesic he ingested to counter the uneasiness he felt that night.

Some may find it interesting to note that the only foreign substances found in Bruce was the equagesic and some cannabis he had apparantly eaten. Though the importance of the latter has been disputed. (source of last two paragraphs: see first source).