[Prolonged anticoagulation following chlorophacinone poisoning]

In 1985 and 1986 the Swiss Toxicologic Information Center registered 152 cases of rodenticide poisoning. Among those substances chlorophacinone, an indanedione derivative, has a prolonged antivitamin K effect. We report here the case of an eighteen-year-old female hospitalized 3 days after deliberately ingesting some 100 mg chlorophacinone. Her Quick time at admission was less than 10% (Prothrombin time 79 sec., normal control 12 sec.). Under high dose vitamin K therapy the Quick was rapidly corrected but fell again on each vitamin K withdrawal. In a search for a relation between the variations of prothrombin time and chlorophacinone plasma levels, these were assessed by HPLC. Prothrombin time (and vitamin K dependent factors VII and X) finally normalized only 7 weeks after chlorophacinone ingestion. Clinical condition remained satisfactory throughout and other biological parameters unaffected. This case emphasizes the need for prolonged clinical and laboratory follow-up for rodenticide intoxications and for vitamin K administration for several weeks.