Adherence and Concomitant Medication Use among Patients on Warfarin Therapy: Insight from a Large Pharmacy Dispensing Database in Japan.

Warfarin is a drug used for anticoagulation management, with a narrow therapeutic range and multiple drug-drug interactions. Adherence and proper use of concomitant medication are thus fundamental to the efficacy and safety of warfarin therapy. In 2012, we retrospectively analyzed data from three large-scale pharmacy chains in Japan. We included all adults (≥ 20 years old) with at least one record of warfarin dispensation. We examined patient demographic data, adherence as measured by medication possession ratio (MPR), and co-dispensation focusing on the number of concomitant dispensations and concurrent use of medications that increase bleeding risk. Thresholds of underadherence and overadherence were set at <0.9 and >1.1, considering the narrow therapeutic window. We reviewed 443007 warfarin dispensation records of 71340 individuals (median age, 73 years; 62% male). The MPR was 1.0 (interquartile range: 0.96-1.0), and underadherence and overadherence was found in 16.3 and 1.9% of individuals, respectively. The median number of co-dispensed drugs was eight at each pharmacy encounter, which did not differ by age group. Drugs associated with a high bleeding risk were dispensed in 40.0% of encounters and accounted for 16.4% of all co-dispensed drugs. In summary, we found optimal overall adherence, as assessed by MPR, among our Japanese study population, even when defining a strict cut-off value. However, polypharmacy was common in all age groups and medications with a high bleeding risk profile were often co-dispensed with warfarin. Future research addressing how these dispensation patterns affect patient outcome is warranted.

Root cap-dependent gravitropic U-turn of maize root requires light-induced auxin biosynthesis via the YUC pathway in the root apex.

Gravitropism refers to the growth or movement of plants that is influenced by gravity. Roots exhibit positive gravitropism, and the root cap is thought to be the gravity-sensing site. In some plants, the root cap requires light irradiation for positive gravitropic responses. However, the mechanisms regulating this phenomenon are unknown. We herein report that maize roots exposed to white light continuously for ≥1-2h show increased indole-3-acetic acid (IAA) levels in the root tips, especially in the transition zone (1-3mm from the tip). Treatment with IAA biosynthesis inhibitors yucasin and l-kynurenine prevented any increases in IAA content and root curvature under light conditions. Analyses of the incorporation of a stable isotope label from tryptophan into IAA revealed that some of the IAA in roots was synthesized in the root apex. Furthermore, Zmvt2 and Zmyuc gene transcripts were detected in the root apex. One of the Zmyuc genes (ZM2G141383) was up-regulated by light irradiation in the 0-1mm tip region. Our findings suggest that IAA accumulation in the transition zone is due to light-induced activation of Zmyuc gene expression in the 0-1mm root apex region. Light-induced changes in IAA levels and distributions mediate the maize root gravitropic U-turn.