The Sixth Doctor found himself poisoned by a large, concentrated dose of aspirin, which he knew to cause severe allergic, pulmonary and cerebral embolism in Time Lords. He fell into a deep coma while his body fought off the effects. (PROSE: Burning Heart)
Another such attempt was made on the Sixth Doctor's life when an alien who knew Time Lord physiology poisoned his tea with soluble aspirin. The Doctor counteracted the aspirin by eating chocolate, a source of simple triglycerides which the Doctor's body easily absorbed. This negated the anti-platelet effect of the aspirin. (AUDIO: The Condemned)
The tablet which would have killed the Doctor in The Mind of Evil was not specified as aspirin, but was assumed to be so. It became accepted as such after Kate Orman specified the Doctor's weakness toward aspirin in The Left-Handed Hummingbird. Other references followed that novel.