A 23-year-old woman presents after an overdose with large pupils and profuse sweating. What is the most likely agent responsible?

The scenario describes a 23-year-old woman presenting after an overdose characterized by large pupils (mydriasis) and profuse sweating. Cocaine is a stimulant that can cause a range of sympathomimetic effects, including increased sympathetic outflow, which leads to dilated pupils and excessive sweating due to its effect on adrenergic receptors.

Cocaine is known to increase the release of norepinephrine and other neurotransmitters, resulting in symptoms that align with the clinical presentation described. The combination of mydriasis and diaphoresis is particularly characteristic of cocaine intoxication. This aligns with the pharmacological actions of cocaine, which stimulate the central nervous system and enhance sympathetic activity.

In contrast, other substances listed do not typically lead to a combination of mydriasis and sweating. For instance, Jimson weed can cause anticholinergic effects, which would typically result in dilated pupils but not necessarily profuse sweating. Heroin, an opioid, usually causes miosis (constricted pupils) and does not lead to increased sweating, and insulin is not a drug associated with these symptoms despite the potential for hypoglycemia leading to sweating. Overall, the symptoms observed in the patient are most consistent with cocaine use.