Information regarding drug interactions is useful for avoiding adverse effects from medicinal drug administration, and similar information is obviously desirable for health food products and supplements. When examining findings related to drug-supplement interactions, it is vital to understand pharmacokinetics such as drug absorption, distribution, metabolism, and excretion. The interaction disposition of one particular drug is primarily related to inhibition and induction of the drug-metabolizing enzyme cytochrome P450 (CYP). Thus, experiments evaluating the expression level of CYP isoforms in human hepatic microsomes and their relative ratio in drugs metabolized by them would be useful. However, investigations of drug-supplement interactions such as inhibition tests using the cDNA-expressed human CYP and specific substrates in combination are scarce. It is essential to consider studies for averting such interactions and to disseminate information for improving safety.

BACKGROUNDAlthough various studies have been conducted on the effects of radiation therapy for prostate cancer, rectal toxicity after radiation therapy for prostate cancer, which is an important late adverse event associated with radiation therapy, has not been sufficiently examined. This study aimed to assess the associations of late rectal disorder (LRD) with dosimetric, anatomic, and clinical factors in patients with prostate cancer who underwent three-dimensional conformal radiation therapy (3D-CRT).

METHODSWe retrospectively analyzed 104 patients undergoing 3D-CRT between January 2009 and October 2011. Thirty patients were administered anticoagulation/antiplatelet (AC/AP) agents. The standard dose was 74 Gy. Uni- and multi-variate analyses were performed to identify factors predictive of LRD after 3D-CRT.

RESULTSThe median follow-up period was 66 (range: 14-87) months. LRD occurred in 10.6% (11/104) of patients. The median time from RT to LRD was 15 months (range: 7-41 months). Sixty-four percent of those with LRD (7/11 patients) had been given AC/AP agents. Fifty-five (6/11) patients had severe internal iliac artery calcification. By univariate analysis, significant predictors of LRD were internal iliac artery calcification, administration of AC/AP agents, and age. Being very elderly was the significant predictor identified by multivariate analysis (P = 0.0276). For patients receiving AC/AP agents and those with severe internal iliac artery calcification, the LRD incidences were 23.3% (7/30 patients) and 23.1% (6/26 patients), respectively, and being 75 years of age or older was a significant predictor in these subsets.

CONCLUSIONSOur results suggest advanced age, administration of AC/AP agents, and severe internal iliac artery calcification to be risk factors for LRD in patients undergoing standard RT. Therefore, it is necessary to administer radiation with particular caution in the very elderly, especially those receiving AC/AP agents and/or with severe internal iliac artery calcification.

As a screening tool for detecting latent pre-locomotive syndrome (latent pre-LS) in women over the age of 40, measuring handgrip strength with a cut-off value of 26 kg was proposed in a previous report. However, this screening method missed 22% of latent pre-LS. It would be beneficial to screen almost persons with latent pre-LS in community pharmacies. In this study, it was investigated whether screening using the combination of measuring handgrip strength and the questionnaire, “Loco-check,” which was proposed by the Japanese Orthopaedic Association, improved the detection of latent pre-LS in the same group mentioned above. Combining only one of the “Loco-check” questions, “I cannot put on a pair of socks while standing on one leg,” with the measurement of handgrip strength with the cut-off value of 26 kg, the detection of latent pre-LS was increased to 90.2%. The odds ratio was 9.72 in logistic regression analysis. Using the combination of the measurement of handgrip strength and the response to one question is both rapid and convenient. Therefore, in this study, this screening combination is proposed to be a useful tool in community pharmacies for detecting early latent pre-LS.