What are fever-producing toxins from gram-negative bacteria that may contaminate radiopharmaceuticals called?

Fever-producing toxins from gram-negative bacteria that may contaminate radiopharmaceuticals are referred to as pyrogens. These substances can induce fever when introduced into the body, leading to a significant concern in pharmaceuticals, particularly those that are intended for injection or infusion.

The term "pyrogen" specifically describes substances that cause fever, and in the context of gram-negative bacteria, it's associated with components of the bacterial cell wall, primarily lipopolysaccharides. These lipopolysaccharides can be released when the bacteria die or are disrupted, which can contaminate products like radiopharmaceuticals.

In contrast to pyrogens, endotoxins are related but represent a specific type of pyrogen associated with the outer membrane of gram-negative bacteria; thus, while they are often involved, the broader term "pyrogens" is typically used when discussing contamination in pharmaceuticals. Other terms in the choices, such as mycotoxins (produced by fungi) and exotoxins (produced actively by both gram-positive and gram-negative bacteria), refer to different categories of toxins that do not specifically pertain to the fever-inducing properties related to gram-negative contamination in radiopharmaceuticals.