Prevalence and risk of potential cytochrome P450-mediated drug-drug interactions in older hospitalized patients with polypharmacy.

Background: As rates of polypharmacy rise and medication regimens become more complex, the risk of potential cytochrome P450 (CYP)-mediated drug-drug interactions (DDIs) is a growing clinical concern for older adults.

Objective: To determine the prevalence of potential CYP-mediated DDIs in older hospitalized adults with polypharmacy and analyze the relationship between the number of drugs dispensed and the probability of these interactions in this high-risk population.

Methods: A prospective 16-week cohort study was conducted among consecutive new patients aged 65 years and older with polypharmacy (>5 drugs) admitted to a community hospital.

Detection and prevention of drug-drug interactions in the hospitalized elderly: utility of new cytochrome p450-based software.

Background: Polypharmacy increases the risk of cytochrome P450-based drug-drug interactions (CYP450-DDIs), leading to decreased therapeutic efficacy or increased drug toxicity.

Objective: The aims of this study were to investigate the utility of a new CYP450-DDI software, InterMED-Rx, in aiding pharmacists in detecting CYP450-DDIs in hospitalized elderly patients and to ascertain pharmacists' agreement on how to intervene for each CYP450-DDI.

Methods: A consensus panel of geriatric pharmacists first established guidelines for managing clinically relevant pharmacokinetic CYP450-DDIs.

Gender-related differences in drug-induced prolongation of cardiac repolarization in prepubertal guinea pigs.

Underlying mechanisms of drug-induced long QT syndrome are not fully understood. Our objective was to evaluate gender-related differences for block of the rapid (I(Kr) ) or/and the slow (I(Ks)) components of the delayed rectifier potassium current in prepubertal male and female guinea pigs (n = 120) treated with or without verapamil. Indapamide (I(Ks) blocker) prolonged the monophasic action potential duration at 90% repolarisation (MAPD( 90)) in females more than in males (15.