Evaluation of plasmapheresis in the treatment of an acute overdose of carbamazepine.

OBJECTIVE

To report the use of plasmapheresis in the treatment of an acute overdose of carbamazepine.

CASE SUMMARY

A 21-year-old black man was admitted unresponsive and combative following a carbamazepine overdose. The total body load of carbamazepine was approximated at 5.91 g using an assumed volume of distribution of 1.4 L/kg. The patient underwent three plasmapheresis treatments. A total of only 335.82 mg of carbamazepine was removed by this process.

DISCUSSION

Case reports in the literature were reviewed and compared. Carbamazepine concentrations lack correlation with the clinical outcome. Our patient's symptoms were consistent with the Weaver classification system. Carbamazepine clearance increased by almost 70 percent above its natural clearance during plasmapheresis. However, a significant rebound effect was observed after plasmapheresis: 40.1 percent after the first and 18.3 percent after the second treatment.

CONCLUSIONS

Plasmapheresis did not seem to have a great impact on the patient's clinical status. Under the circumstances we find it extremely difficult to recommend plasmapheresis in the treatment of an acute overdose of carbamazepine.