Differential Effects of Ca2+ Channel Blockers Nifedipine and Cilnidipine on Arterial Elasticity in the Aortic and Femoral Arterial Segments of Anesthetized Rabbits.

Ca2+ channel blockers have potent vasodilatory effects and excellent efficacy in preserving organ blood flow. These hemodynamic actions may be partly controlled by the functional stiffness of conduit arteries. In this study, we assessed the effects of the L-type Ca2+ channel blocker nifedipine on aortic and femoral arterial stiffness (referred to as aortic ß and femoral ß, respectively) in anesthetized rabbits. To further clarify the involvement of the autonomic nervous system, we compared the effects of nifedipine with those of the L/N-type Ca2+ channel blocker cilnidipine. Further, the effect of the α-adrenergic receptor blocker doxazosin on the effects of nifedipine on arterial elasticity was examined. An antihypertensive dose of nifedipine (300 µg/kg, administered intravenously) was found to increase the aortic ß but hardly affected the femoral ß. An antihypertensive dose of cilnidipine (30 µg/kg, administered intravenously) increased the aortic ß but decreased the femoral ß. Interestingly, nifedipine decreased the femoral ß in the presence of the α-adrenoceptor blocker doxazosin (1 mg/kg, administered intravenously). These effects suggest that L-type Ca2+ channel blockers essentially increase vascular elasticity via the decrement in arterial stiffness in the femoral artery segment, which is modified by the presence or absence of the inhibitory effect of each drug on reflex sympathetic nerve activity, while decreasing vascular elasticity via the increment in arterial stiffness in the aortic segment independently of sympathetic nerve activity.

Evaluation of pregabalin-induced adverse events related to falls using the FDA adverse event reporting system and Japanese Adverse Drug Event Report databases.

WHAT IS KNOWN AND OBJECTIVE: Pregabalin is used for neuropathic and postherpetic pain and generalized anxiety. The aim of this study was to obtain the onset profiles of adverse events (AE) related to falls (AEFs) such as "somnolence," "dizziness," "loss of consciousness" and "fall" onset and several clinical factor combinations such as age and administered dose, using spontaneous reporting system (SRS) analysis such as the US Food and Drug Administration Adverse Event Reporting System (FAERS) database and the Japanese Adverse Drug Event Report (JADER) database. METHODS: We used the reporting odds ratio (ROR) to analyse the association between pregabalin and AEFs. Additionally, we used the time-to-onset analysis. RESULTS AND DISCUSSION: The crude RORs of AEFs such as somnolence and dizziness were higher than one for both the databases. The adjusted RORs for AEFs in the ≥60 years age group compared to those in the <60 years age group for the FAERS and JADER databases were 1.46 (95% CI = 1.39-1.53; P < 0.0001) and 2.58 (95% CI = 2.06-3.27; P < 0.0001), respectively. In the JADER database, the median and quartile range for AEFs with pregabalin, at ≤75 and ≥100 mg/d, were 2.0 (0.0-5.0) and 2.0 (1.0-4.3) days, respectively. Additionally, 57.2% of AEFs (four preferred terms) were observed within 2 days after administration. WHAT IS NEW AND CONCLUSIONS: This study is the first to evaluate the relationship between pregabalin and AEFs using the SRS analysis strategy. The risk of AEFs in the ≥60 years age group might increase compared to that in the <60 years age group. AEFs occurred almost within 1 week after pregabalin administration, and the median for AEF onset was 2 days. Our results show that patients should be closely monitored for AEFs for 1 week from the start of pregabalin administration.

Analysis of the Interaction between Clopidogrel, Aspirin, and Proton Pump Inhibitors Using the FDA Adverse Event Reporting System Database.

Clopidogrel is an antiplatelet agent widely used in combination with aspirin to limit the occurrence of cardiovascular (embolic/thrombotic) events. Consensus guidelines recommend proton pump inhibitors (PPIs) as a gastrointestinal (GI) prophylactic measure for all patients receiving dual antiplatelet therapy with clopidogrel and aspirin. The objective of this study was to analyze the effect of the simultaneous use of clopidogrel, aspirin, and PPIs on hemorrhagic and embolic/thrombotic events using the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. Reports of hemorrhagic and embolic/thrombotic events between 2004 and 2013 were analyzed with a reporting odds ratio (ROR) algorithm and logistic regression methods. The Medical Dictionary for Regulatory Activities Preferred Terms was used to identify such events. Regarding hemorrhagic events, the adjusted RORs of the concomitant use of aspirin and clopidogrel and those of PPIs prescribed with aspirin and clopidogrel were 4.40 (95% confidence interval [CI], 4.02-4.81) and 3.40 (95% CI, 2.84-4.06), respectively. For embolic/thrombotic events, the adjusted RORs of the concomitant use of aspirin and clopidogrel and those of PPIs prescribed with aspirin and clopidogrel were 2.37 (95% CI, 2.16-2.59) and 2.38 (95% CI, 2.00-2.84), respectively. Among patients included in the FAERS database, the concurrent use of aspirin and clopidogrel with PPIs reduced the adjusted ROR of GI hemorrhagic events. PPIs had little influence on the adjusted ROR of embolic/thrombotic events. These results support the use of PPIs as a preventive measure against GI hemorrhagic events for patients receiving clopidogrel and aspirin.

Analysis of polypharmacy effects in older patients using Japanese Adverse Drug Event Report database.

Population aging is a global phenomenon, and choosing appropriate medical care for the elderly is critical. Polypharmacy is suspected to increase the risk of adverse events (AEs) in older patients. We examined the AE profiles associated with polypharmacy and aging using the Japanese Adverse Drug Event Report (JADER) database. We attempted to mitigate the effect of patient-related factors using a multiple-logistic regression technique and data subsetting. We selected case reports for AEs as specified in the Medical Dictionary for Regulatory Activities (MedDRA). The association between polypharmacy and "renal disorder" or "hepatic disorder" was evaluated using reporting odds ratio (ROR) and adjusted for covariates using multiple-logistic regression. For renal disorder, advanced polypharmacy showed higher adjusted RORs, because the value of administered drugs group [1.82 (1.76-1.88), ≥ 10] was higher than that of the number of administered drugs group [1.27 (1.24-1.31), 5-9]. The lower limit of the 95% confidence interval (CI) of adjusted ROR for age (≥ 60 years) was > 1 for renal disorder. For hepatic disorder, the adjusted RORs were as follows: 1.17 (1.14-1.20) for the number of administered drugs group (5-9) and 1.14 (1.11-1.18) for the number of administered drugs group (≥ 10). The adjusted RORs of hepatic disorder compared to those of renal disorder had lower adjusted RORs related to the increase in the number of administered drugs. Therefore, elderly individuals should be closely monitored for the occurrence of renal disorder when they are subjected to polypharmacy. This approach might apply to the simultaneous evaluation of the AE risk of polypharmacy and aging.