Which of the following is NOT an effect associated with barbiturates?

Barbiturates are a class of medications primarily used for their sedative and hypnotic properties. They often induce sedation, which is the calming of the nervous system, and hypnosis, which refers to the induced state of sleep or trance. Furthermore, they can sometimes lead to excitement as a paradoxical effect, particularly at lower doses in some individuals, which can cause unexpected reactions like restlessness or agitation.

Analgesia, however, is specifically the relief of pain and is not a primary action of barbiturates. While these drugs can produce some degree of pain relief through their overall sedative effects, they do not possess significant analgesic properties like opioids or certain other medications that are specifically designed to alleviate pain. Thus, when considering the core pharmacological effects of barbiturates, analgesia stands out as the option that is not typically associated with their use.