Role of dantrolene in dinitrophenol (DNP) overdose: A continuing question?

BACKGROUND: 2,4-Dinitrophenol (DNP) is a known uncoupler of oxidative phosphorylation that clinically results in hyperthermia, tachycardia, tachypnea, and metabolic acidosis. Overdoses of DNP are often fatal and there is no specific reversal therapy. Dantrolene interferes with calcium release in skeletal muscle and is traditionally used to treat malignant hyperthermia. There has been limited published data on its use in DNP toxicity. We present two cases of DNP toxicity that were treated with dantrolene. CASE 1: A 22-year-old male presented following an overdose of his bodybuilding supplements including DNP. He became altered, tachycardic, and hyperthermic to 40.0C. He required intubation and aggressive cooling. He received multiple doses of dantrolene over the initial 36 h with resolution of his hyperthermia. He was extubated and discharged home on hospital day 6. CASE 2: A 20-year-old male presented following a staggered ingestion of DNP. He was tachypneic and tachycardic on arrival. He became hyperthermic to 40.2C and required intubation. He underwent aggressive cooling and received 200 mg of IV dantrolene. His temperature normalized, however, he expired 4 h after ED arrival. CONCLUSION: DNP toxicity has limited treatment options. Dantrolene may ameliorate the hypermetabolic state in DNP toxicity by lessening excitation-contraction coupling in muscle cells and improving the associated hyperthermia. Our cases demonstrate the hyperthermia reducing effects of dantrolene in DNP toxicity and contribute to the existing literature on this topic. Being aware of the possible use of dantrolene to treat the associated hyperthermia could assist emergency physicians in the treatment of DNP toxicity.

Hyperinsulin therapy for calcium channel antagonist poisoning: a seven-year retrospective study.

The use of hyperinsulin therapy (HIT) in severe calcium channel antagonist (CCA) poisoning has become a more common therapy within the last decade. The objective of this study is to report 7 years of experience recommending HIT. This was a retrospective chart review utilizing our regional poison center (RPC) data from January 1, 2002, through December 31, 2008. All cases of CCA poisoning receiving HIT were searched. Endpoints included the number of CCA cases utilizing HIT, insulin dose, time of initiation of HIT, patient outcome, adverse events, age, glucose concentration, and lowest systolic blood pressure recorded. Forty-six cases of CCA poisoning were managed with HIT over 7 years. All the patients received standard antidotal therapy (= intravenous fluids, calcium salts, glucagon, and pressors). HIT administration followed our RPC recommendation 23 times (50%), and no hypoglycemic events occurred. Means (age, highest glucose measured, and lowest systolic blood pressure measured) were 51 years, 282 mg/dL, and 74 mm Hg, respectively. Our RPC recommendations for HIT were followed 50% of the time over the last 7 years. In light of the lack of hypoglycemia associated with HIT in our study population, we recommend HIT as an early and safe antidote in significant CCA poisoning.