Which statement about barbiturates is true?

Barbiturates, particularly when administered improperly, can cause significant discomfort and pain. Administering barbiturates outside the vein, also known as extravasation, can lead to tissue necrosis and considerable pain for the animal. This characteristic is crucial for proper animal care and handling, as it highlights the importance of administering these substances only via a proper route. Understanding this aspect of barbiturates is essential for individuals involved in research and animal care to ensure the welfare of laboratory animals.

The other aspects related to gasping for air, the metabolic breakdown of barbiturates, and the classification of pentobarbital need to be considered in a broader context of their pharmacology but do not emphasize the immediate concern regarding pain and tissue safety associated with extravascular administration.