Acute poisoning by pirimicarb: clinical and toxicological features

Anticholinesterase compounds like organophosphorous and carbamates account for the majority of poisonings by the insecticides class agents. While the toxicokinetic depends on the extent of exposure and also on the chemical structure of the agent, the clinical symptoms range from the classic cholinergic syndrome to flaccid paralysis and intractable seizures. The carbamate ester pirimicarb (Pirimor), a toxic N-dimethylcarbamate pesticide, is used as insecticide. Our case presents the first poisoning associated with clinical and analytical findings.

A 68-year-old male ingested an unknown amount of pirimicarb and developed cholinergic symptoms immediately, accompanied by seizures.

He was admitted in the Intensive Care Unit (ICU) and received intensive care including intubation for hypoxemia following seizures and drug therapy of hypertensive dysregulation. No Atropine but benzodiazepines were administered. The patient recovered in the ICU after 3 days and was discharged after a week.

Pirimicarb stomach, blood, and urine levels were determined on admission and during hospitalisation. Using an one-compartment model the pesticide elimination was estimated and its terminal half-life in plasma, t1/2, was found to be 3.8 hours. The butyryl cholinesterase (BChE) activity was at the lower level of detection on the admission and recovered during the following 24 hours.