Accidental intramuscular injection of mechlorethamine

Area of Science:

• Dermatology
• Pharmacology
• Toxicology

Background:

• Mechlorethamine is a nitrogen mustard alkylating agent used in chemotherapy.
• Intramuscular administration of mechlorethamine can lead to severe local tissue damage.
• Psoriasis is a chronic autoimmune disease affecting the skin.

Observation:

• A 55-year-old male with chronic, active diffuse psoriasis received an accidental 30 mg intramuscular injection of mechlorethamine.
• Following the injection, a 1/6 M sodium thiosulfate solution was infused around the injection site approximately 5 hours later.
• Systemic effects of mechlorethamine were observed, but significant muscular and skin necrosis did not occur.

Findings:

• Intramuscular mechlorethamine administration resulted in only minimal local tenderness at the injection site.
• The sodium thiosulfate infusion appeared to mitigate the expected severe local tissue destruction.
• Despite systemic absorption, the localized toxic effects were significantly reduced.

Implications:

• Sodium thiosulfate may serve as a potential antidote for accidental mechlorethamine extravasation or intramuscular injection.
• This case highlights a possible therapeutic strategy to manage accidental mechlorethamine exposure.
• Further research is warranted to confirm the efficacy and safety of sodium thiosulfate as an antidote for mechlorethamine-induced tissue injury.