Drug-induced QT-interval prolongation: considerations for clinicians.

Drug-induced proarrhythmia is a frequently encountered clinical problem and a leading cause for withdrawal or relabeling of prescription drugs. Suppression of the rapid component of the delayed rectifier potassium current, I(Kr), represents the principal pharmacodynamic mechanism leading to heterogeneous prolongation of the ventricular action potential and prolongation of the QT interval clinically. However, the risk of proarrhythmia by QT-interval-prolonging drugs is variable and critically dependent on several factors leading to multiple reductions in the cardiac repolarization reserve.

Effect of clinical characteristics on neutropenia-related inpatient costs among newly diagnosed non-Hodgkin's lymphoma cases during first-course chemotherapy.

Study Objective: To estimate the costs of hospitalization for neutropenia among chemotherapy-treated patients with newly diagnosed non-Hodgkin's lymphoma and to assess baseline patient factors associated with these costs.

Design: Retrospective cohort study.

Data Source: Linked Surveillance, Epidemiology, and End Results Program-Healthcare Cost and Utilization Project databases for Iowa from 1993-1998.

Was breast conserving surgery underutilized for early stage breast cancer? Instrumental variables evidence for stage II patients from Iowa.

Objective: To estimate the average survival effects of breast conserving surgery plus irradiation relative to mastectomy for marginal stage II breast cancer patients in Iowa from 1989-1994. DATA SOURCES/DATA SETTING: Secondary linked Iowa SEER Cancer Registry--Iowa Hospital Association discharge abstract data for women in Iowa with stage II breast cancer from 1989-1994.

Study Design: Observational instrumental variables (IV) analysis.

Days of prophylactic filgrastim use to reduce febrile neutropenia in patients with non-Hodgkin's lymphoma treated with chemotherapy.

Background: Filgrastim prophylaxis lessens the occurrence of febrile neutropenia in patients with non-Hodgkin.s lymphoma (NHL) treated with chemotherapy, but differences in days of therapy and mode (primary or secondary) of prophylaxis may affect clinical outcomes.

Objective: To describe the patterns of use of filgrastim prophylaxis, especially days of therapy and mode, and the possible associated incidence of febrile neutropenia in patients treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy.

Factors associated with early termination of CHOP therapy and the impact on survival among patients with chemosensitive intermediate-grade non-Hodgkin's lymphoma.

Background: Six to eight cycles of CHOP therapy (cyclophosphamide, doxorubicin, vincristine, and prednisone) is standard for intermediate-grade non-Hodgkin's lymphoma (NHL) but is associated with toxicity that may cause premature termination of therapy.

Methods: We studied factors associated with premature termination of CHOP therapy (receiving fewer than 6 cycles) and the relationship of premature termination with survival. Subjects consisted of a population-based sample of Iowa residents with intermediate-grade NHL who were planned to receive > or = 6 or more cycles of CHOP and who were chemosensitive (ie, achieved a documented partial or complete response to CHOP).

Anticholinergic agents for the treatment of "death rattle" in patients with myasthenia gravis.

Difficulty clearing upper airway secretions (death rattle) is a frequent problem at the end of life. Treatment often includes the use of anticholinergic drugs. Myasthenia gravis is a disease characterized by muscle weakness and fatigue caused by an immune-mediated deficiency of acetylcholine receptors at the neuromuscular junction, and it is treated with anticholinesterase agents.

Dose conversion from recombinant human erythropoietin to darbepoetin alfa: recommendations from clinical studies.

Recombinant human erythropoietin (r-HuEPO, epoetin alfa), is an established and effective treatment for anemia associated with both chronic kidney disease (CKD) and cancer and has improved the management of anemia over alternatives such as transfusion. Darbepoetin alfa is a new erythropoietic agent with a 3-fold longer half-life and increased in vivo potency relative to r-HuEPO. These properties allow patients to be treated with longer dosing intervals than with r-HuEPO.