Intramuscular injection of paraquat for suicidal attempt: A rare case report

To the Editor:

Oral ingestion is the most common method of paraquat poisoning.¹ Intramuscular (IM) paraquat injection is extremely rare.^2,3 We wish to highlight the clinical presentation of such a case and illustrate delays in urine test positivity for paraquat in this situation.

A 25-year-old female was referred to the clinical toxicology department of Noor General Teaching Hospital, Isfahan (Iran), 5 hours after deliberate IM injection of 15 ml of 20% paraquat into her buttocks.

On admission, she was fully conscious and had normal vital signs, but complained numbness in her four extremities and muscle pain in lower extremities. The only abnormal physical finding were two 5–10-cm-diameter injection sites, blue-purple discoloration of the skin in her both gluteal areas.

Initial blood count, clotting, electrolytes, and LFTs were normal. The result for a semiquantitative color intensity test (sodium dithionite) on urine performed on admission was negative.

Three hours after admission (about 8 hours after the initial injection), the sodium dithionite urine test became positive but not dark blue. Hemodialysis was implemented empirically, and after the first 4 hours of hemodialysis the sodium dithionite urine test was repeated and was now dark blue. By the first day, she developed shortness of breath, dull chest pain, and restlessness; the size of the injection sites enlarged and became painful. By the second day, the patient developed signs of progressive renal and hepatic failure, and severe dyspnoea. Serial coagulation studies became worse in subsequent tests parallel to deterioration of patient general condition.

The patient died from severe hypoxemia at 41 hours subsequent to injection.

The course of toxicity was as might be expected and, as previously reported, rapid. The lack of positivity of urine tests soon after a potential IM injection of paraquat is worthy of note in those countries where this herbicide is still available.