Interleukin-18 and interleukin-18 binding protein levels before and after percutaneous coronary intervention in patients with and without recent myocardial infarction.

Serum levels of interleukin-18 (IL-18) and its endogenous antagonist IL-18 binding protein were measured in 84 patients before and after coronary angioplasty. Patients who had high levels of troponin I immediately before angioplasty were considered to have experienced a "recent" myocardial infarction. Concentrations of IL-18 (355 vs 316 pg/ml) and ratio of IL-18 to IL-18 binding protein (107 vs 69) were significantly higher among patients who had recent myocardial infarction than among those who did not, indicating a relation between unopposed IL-18 activity and recent myocardial infarction.

Antipsychotic drugs and QT interval prolongation.

The QTc prolongation by antipsychotic drugs is of major concern, especially in light of the data indicating an increased risk of sudden death in psychiatric patients taking these drugs. Sudden death in psychiatric patients could be partially attributed to drug-induced torsades de pointes and for this reason careful evaluation of QTc prolonging properties of antipsychotic drugs is needed. Antipsychotic drugs prolong QT interval usually by blocking the potassium IKr current. Improved understanding of ion channel structure and kinetics and its role in repolarization has tremendous impact on understanding of the mechanisms of drug-induced QT prolongation and torsades de pointes. Proarrhythmia caused by a QT-prolonging drug occurs infrequently, and usually multiple factors need to operate to precipitate such an event including a combination of two or more drugs affecting the same pathway, hypokalemia, and possibly genetic predisposition. Currently prescribed antipsychotics might cause QT prolongation ranging from 4-6 ms for haloperidol and olanzapine to 35 ms for thioridazine. The response of a patient to a drug is very individual and therefore an individualized system of drug administration and monitoring needs to be developed which takes into account baseline QTc duration and its changes after a drug was introduced. A systematic approach while stratifying psychiatric patients as those with short QTc (QTc < or = 0.41 sec), borderline QTc (QTC = 0.42-0.44 sec), and prolonged QTc (0.45 sec) is being proposed to improve the safety of administering antipsychotic drugs and to decrease the risk of drug-related sudden death in psychiatric patients.