Final answer:
The severe life-threatening response to contrast media is known as anaphylaxis, a type I hypersensitivity reaction that is treated with epinephrine.
Step-by-step explanation:
A severe life-threatening response to contrast media is considered anaphylaxis, which is a systemic and potentially life-threatening type I hypersensitivity reaction. This condition is treated with epinephrine, a drug that is used to counteract the effects of an anaphylactic shock. During anaphylaxis, a massive release of histamines can lead to symptoms such as a drop in blood pressure, changes in heart rate, shortness of breath, and swelling of the tongue and throat, which can be fatal without prompt emergency treatment.