Alcavixin Overdosage

Side effect following the use of vincristine is dose related. Extreme care must be used in calculating and administering the dose of vincristine since overdosage may have a very serious or fatal outcome. Do not exceed 2 mg total once dose. Therefore, following administration of doses higher than those recommended, patients can be expected to experience exaggerated side effects.
In children under 13 years of age, death has occurred following doses of vincristine that were 10 times those recommended for therapy. Severe symptoms may occur in this patient group following dosages of 3 to 4 mg/m². Adult can be expected to experience severe symptoms after single doses of 3 mg/m² or more. Therefore, following administration of doses higher than those recommended, patients can be expected to experience exaggerated side effects.
Treatment: Supportive Care: Prevention of side effects resulting from the syndrome of appropriate antidiuretic hormone secretion (preventive treatment would include restriction of fluid intake and perhaps the administration of a diuretic affecting the function of Henle's loop and the distal tubule).
Administration of anticonvulsants.
Use of enemas or cathartics to prevent ileus (in some instances, decompression of the gastrointestinal tract may be necessary).
Monitoring the cardiovascular system.
Determining daily blood counts for guidance in transfusion requirements.
Folic acid has been observed to have a protective effect in normal mice, which were administered lethal doses of vincristine. Isolated case reports suggest that folinic acid may be helpful in treating humans who have received an overdose. It is suggested that 15 mg of folinic acid be administered intravenously every 3 hours for 24 hours and then every 6 hours for at least 48 hours. Theoretically (based on pharmacokinetic data), tissue levels of vincristine can be expected to remain significantly elevated for at least 72 hours. Treatment with folinic acid does not eliminate the need for the above mentioned supportive measures.
Most of an intravenous dose of vincristine is excreted into the bile after rapid tissue binding. Because only very small amounts of the drug appear in dialysate, hemodialysis is not likely to be helpful in cases of overdosage. An increase in the severity of side effect may be experienced by patients with liver disease that is severe enough to decrease biliary excretion. Enhanced fecal excretion of parenterally administered vincristine has been demonstrated in dogs pretreated with cholestyramine. There are no published clinical data on the use of cholestyramine as an antidote in humans. There are no published clinical data on the consequences of oral ingestion of vincristine. Should oral ingestion occur, the stomach should be evacuated. Evacuation should be followed by oral administration of activated charcoal and a cathartic.