In a case of a 2-year-old who ingested clonazepam, which antidote is beneficial?

Flumazenil is the correct choice in this case involving a 2-year-old who ingested clonazepam. Clonazepam is a benzodiazepine, which can depress the central nervous system leading to symptoms such as sedation, respiratory depression, and altered consciousness when ingested in excess. Flumazenil acts as a competitive antagonist at the benzodiazepine sites on the GABA-A receptor, effectively reversing the effects of benzodiazepines.

In situations of benzodiazepine overdose, the administration of flumazenil can rapidly restore consciousness and improve respiratory function, making it a valuable antidote. However, caution is necessary, especially in cases of poly-drug overdose, as flumazenil can precipitate withdrawal symptoms in patients with a dependency on benzodiazepines or lead to severe complications with other substances.

The other options are not suitable antidotes for clonazepam overdose. Naloxone targets opioid receptors and is effective for reversing opioid overdoses, not benzodiazepines. Physostigmine is used for certain types of anticholinergic toxicity but does not have a role in benzodiazepine overdose. Fomepizole is an antidote for methanol or ethylene glycol poisoning