Letter to the Editor: “Comment on “Cytochrome-C Oxidase Inhibition in 26 Aluminum Phosphide Poisoned Patients””

Comment on “Cytochrome-C Oxidase Inhibition in 26 Aluminum Phosphide Poisoned Patients”

To the Editor:

We read with interest the recent article on cytochrome-c oxidase inhibition in aluminum phosphide poisoned patients in India (1). Since this is a rare poisoning in the United States (US), we appreciate the opportunity to read about these patients and to consider the proposed mechanism of toxicity. Phosphine toxicity is becoming more relevant in the US as phosphine is a by-product of the use of red phosphorus in the synthesis of methamphetamines.

However, it remains unclear that there is a relationship between cytochrome-c oxidase activity and phosphine toxicity without measured phosphine concentrations in any of the groups. Also, is the amount of aluminum phosphide ingested in each patient known? Similarly, although the study reported differences in cytochrome-c activity between the control, shock, and aluminum phosphide-exposed groups, there was no demographic information to demonstrate that these groups were otherwise similar. Comorbidities and/or medications may have affected cytochrome-c oxidase activity in all groups. In addition, we would like to know the time lapse between ingestion, blood sampling, and completion of the platelet assay, as this may affect detection of cytochrome-c oxidase activity.

Although it is difficult to make any conclusions on the role of cytochrome-c oxidase activity in the setting of aluminum phosphide poisoning, this report provides a description on the clinical progression of aluminum phosphide poisoning, a rare entity in the US.