All of the following are signs of an anticholinergic drug overdose except:

In the context of an anticholinergic drug overdose, certain key signs and symptoms are commonly observed due to the pharmacological effects of these agents. Anticholinergics inhibit the actions of acetylcholine, leading to a variety of physiological changes.

Dilated pupils, or mydriasis, are a hallmark sign of anticholinergic intoxication, resulting from the blockade of the parasympathetic nervous system. Flushing and tachycardia also occur as the body responds with sympathetic overactivity due to the lack of acetylcholinergic action. Confusion can manifest as a central nervous system effect, particularly in cases of significant overdose, where the anticholinergic effects lead to altered mental status.

In contrast, hypertension is not typically associated with anticholinergic overdose. While some sympathetic stimulation can occur, the primary cardiovascular effects are more likely to involve tachycardia and potential hypotension rather than sustained hypertension. Thus, the absence of hypertension from the expected signs of anticholinergic overdose distinguishes it from the other symptoms listed.