Studies in the 1990s in Australia and the United Kingdom showed that between 8 and 12% of drug overdoses were following TCA ingestion. TCAs may be involved in up to 33% of all fatal poisonings, second only to analgesics.[16][17] Another study reported 95% of deaths from antidepressants in England and Wales between 1993 and 1997 were associated with tricyclic antidepressants, particularly dothiepin and amitriptyline. It was determined there were 5.3 deaths per 100,000 prescriptions.[18] Sodium channel blockers such as Dilantin should not be used in the treatment of TCA overdose as the Na+ blockade will increase the QTI.