Aluminum phosphide poisoning known as rice tablet: A common toxicity in North Iran

Aluminum phosphide (ALP) is a highly effective insecticide and rodenticide used frequently to protect stored grain. Acute poisoning with this compound is common in some countries including India and Iran, and is a serious health problem.

The objective of this study was to survey ALP poisoning locally known as "Rice Tablet" and the outcome in a referral poisoning hospital in Mazandaran province, northern part of Iran.

The study was a cross-sectional study from March 2007 to February 2008. Records of all patients admitted and hospitalized to a referral teaching hospital during the 2 year period were collected. Information including gender, age, cause of toxicity, amount of AIP consumed, route of exposure, time between exposure and hospital admission, signs and symptoms of toxicity at admission, therapeutic intervention, laboratory tests, and outcome were extracted from the patients' notes. Patients who died and survived were compared using appropriate statistical tests.

During the two-year period, 102 patients, 46 men and 56 women with mean (±SD) age 28.5 ± 12.4 year were admitted with ALP poisoning. The most common signs and symptoms at admission were nausea (79.4%), vomiting (76.5%), and abdominal pain (31.4%). 41.1% of the patients showed metabolic acidosis. Suicidal intention was the most common cause of poisoning (97%) leading to 19 (18.6%) deaths. Compared with the patients who survived, those who died had taken higher amount of ALP tablet (2.2 ± 2.4 vs. 1.4 ± 1.0, P < 0.05), had poor liver function test (P < 0.0001) and severe metabolic acidosis (pH: 7.17 ± 0.19 vs. 7.33 ± 0.08, P < 0.0001).

ALP poisoning is a common toxicity in Iran causing high morality. This is a serious health problem in agricultural region where ALP is readily available. Withdrawal of ALP tablet from the market and introduction of safer products as rodenticides and insecticides is recommended.