Certain gastrointestinal and anti-psychotic drugs that interfere with the heart’s electrical activity are associated with a three-fold increased risk of sudden cardiac death, researchers report.Even though these drugs -- which include domeridone, Haldol, and Thorazine -- may increase the risk of sudden cardiac death, the researchers urged caution in response to the study’s findings."These drugs are vital treatments for serious conditions in many cases, so it is essential that patients should not stop taking them on their own initiative. If they are concerned they should talk to their doctor,” study senior author Dr. Bruno Stricker, of the Erasmus Medical Center in Rotterdam, the Netherlands, said in a prepared statement.His team’s study appears in the May 11 issue of the European Heart Journal.