cocktail effect

Effect of two toxic, or potentially toxic, chemicals when taken together rather than separately. Such effects are known to occur with some mixtures of drugs, with the active ingredient of one making the body more sensitive to the other.

This sometimes occurs because both drugs require the same enzyme to break them down. Chemicals such as pesticides and food additives are only ever tested singly, not in combination with other chemicals that may be consumed at the same time, so no allowance is made for cocktail effects.

‘Gulf War syndrome’ may have resulted from the cocktail effect of an anti-nerve gas drug and two different insecticides.