Beyond the Usual: Novel Therapeutic Roles for Established Antidotes

Antidotes play a crucial role in medical toxicology, providing life-saving interventions against a wide range of toxic substances. Despite their long-standing use, new evidence suggests that fomepizole, l -carnitine, and naloxone may have a wider range of applications than previously thought. This manuscript aims to review the emerging evidence for new treatment indications for fomepizole, l -carnitine, and naloxone.

A narrative literature review was conducted to inform clinicians and researchers about the evolving practices of antidote therapy and to identify areas where further research is warranted to optimize patient outcomes.

Fomepizole has proven its service in the treatment of toxic alcohol poisoning. The inhibitory action of fomepizole on the CYP2E1 and JNK pathways opens new avenues for its application as an antidote for a broader panel of intoxications, including paracetamol poisoning. In addition to l -carnitine supplementation to restore valproic acid-induced carnitine deficiency after chronic use or overdose, many other benefits have been attributed to l -carnitine supplementation for the treatment of drug intoxication. The antioxidative effects of carnitine and its role in promoting fatty acid β-oxidation via the mass effect are less well established. Finally, naloxone is known for its antagonistic action in cases of opioid overdose. Regarding novel indications, the most compelling evidence for naloxone as an antidote was found for clonidine and angiotensin-converting enzyme inhibitors.

The repurposing of antidotes such as fomepizole, l -carnitine, and naloxone represents a promising frontier in precision toxicology. As the understanding of molecular toxicology deepens, it is becoming increasingly feasible to match antidotes to specific molecular signatures of toxicity, rather than relying solely on syndromic classifications.