Tylenol is a brand name for the generic pharmaceutical called paracetamol or acetaminophen. It falls under the pharmacological class of non-steroidal anti-inflammatory drugs, or NSAIDs, along with other familiar compounds including ibuprofen, which is marketed under the brand name Advil, and acetylsalicylic acid, which is marketed as Aspirin. Like other NSAID drugs, Tylenol is generally considered to be safe, is available over the counter and has a wide variety of uses.
Physical Properties
Tylenol is an organic molecule of moderate size, consisting of eight carbon atoms, nine hydrogen atoms, a nitrogen atom and two oxygen atoms. The "CRC Handbook of Chemistry and Physics" lists its chemical weight as 151.17 g/mol. According to the Material Safety Data Sheet, it is a white solid at room temperature, with a melting point of 338 degrees F. The crystalline nature of Tylenol makes it nearly impossible to vaporize, and boiling points for the molecule are generally not listed. Its specific gravity is 1.293, making it somewhat denser than water. It is reasonably soluble in water, with approximately 14mg of compound dissolving per milliliter of water at room temperature.
Chemical Reactivity
Tylenol is stable and unreactive with most chemicals. According to the MSDS, it's non-corrosive, non-flammable, and doesn't degrade significantly if stored for long periods of time. Under slightly acidic conditions, Tylenol can react with water to a limited extent producing a chemical called p-aminophenol, which is sometimes used in laboratory chemistry and as a photography solution. Generally, however, Tylenol's chemical reactivity is considered negligible.
Biochemical Properties
Perhaps the most interesting chemical properties of Tylenol are those relating to its interaction with compounds in the body. Tylenol, like many other NSAID drugs, binds to a group of molecules called cyclooxygenases, or COX. The COX molecules are enzymes responsible for a number of functions, including the production of prostaglandins, which lead to inflammation. Tylenol, once it binds to the COX molecules, inhibits their ability to function. Through COX inhibition, Tylenol acts as an anti-inflammatory, analgesic, or pain relieving, and antipyretic, or fever reducing, drug. Another of Tylenol's interesting properties is that it increases concentrations of the natural pain-reducing molecule anandamide in nerve junctions. With anandamide present around the nerves, they are less capable of sending pain signals. This is a second mechanism by which Tylenol reacts with the body to produce pain relief.
Toxic Reactions
One important chemical property of Tylenol is that it can react with cells in the liver and kidneys, leading to potential organ damage if taken in high doses. As the liver, the body's primary organ responsible for detoxification of the blood and removal of chemicals, processes Tylenol, it produces a molecule that can destroy liver cells. The liver has limited ability to prevent and repair damage from this molecule, but repeated exposure to high doses of Tylenol, or a one-time exposure to very high doses of Tylenol, can overwhelm the liver's ability to protect itself and lead to organ failure.
References
- "Material Safety Data Sheet"; Acetaminophen; Rev October, 2005.
- "CRC Handbook of Chemistry and Physics"; David Lide; 1974
