Which of the following is an antidote for salicylate and tricyclic antidepressant toxicity?

Sodium bicarbonate is an effective antidote for salicylate and tricyclic antidepressant (TCA) toxicity due to its ability to alkalinize the urine and serum. In the case of salicylate toxicity, the acidic nature of salicylate can lead to metabolic acidosis, and administering sodium bicarbonate helps to correct this imbalance. For tricyclic antidepressant overdose, sodium bicarbonate can enhance the elimination of the drug by promoting urinary excretion and can also help to mitigate cardiotoxic effects, such as arrhythmias, by correcting the metabolic acidosis.

In contrast, the other options provided serve different medical purposes. Crotalidae polyvalent is an antivenom used to treat snake bites, and deferoxamine is a chelating agent primarily used for iron overload. Naloxone is an opioid antagonist used to reverse opioid overdoses, making it unsuitable for salicylate and TCA toxicity. Each of these options has specific applications that do not pertain to the treatment of salicylate or TCA poisoning.