Failed rescue therapy with rapamycin after paraquat intoxication.

INTRODUCTION: Ingestion of large quantities of paraquat leads to irreversible, often fatal pulmonary fibrosis. Case presentation. A 50-year-old man (body weight of 78.6 kg) ingested 500 mL Gramoxone containing 200 g/L of paraquat in a suicide attempt. The patient did not seek medical attention until 15 h after ingestion. Initial treatment consisted of the administration of intravenous methylprednisolone, 250 mg once daily. Seventy-two hours after ingestion the patient was transferred to our tertiary care center. Paraquat concentration was 0.2 mg/L in the serum and urinary concentration was 4.42 mg/L. Antioxidative therapy including the administration of acetylcysteine and an anti-inflammatory therapy employing methylprednisolone (1 g/day) was started. Extended daily dialysis was initiated. As the high plasma concentration of paraquat indicated a 100% predicted mortality, we expanded treatment strategies by using the antiproliferative agent rapamycin. A dose of 8 mg/day was started 72 h after the intoxication. Maximum rapamycin concentrations amounted to 12.9 microg/L. Despite these efforts, the patient died on day 18 after intoxication from respiratory failure caused by severe pulmonary fibrosis.
CONCLUSION: Despite theoretical considerations suggesting the use of rapamycin in paraquat poisoning, the substance failed to halt the progression of pulmonary fibrosis in this case.