Assessment of the use of angiotensin receptor blockers in major European markets among paediatric population for treating essential hypertension

Prolonged Postoperative Vasoplegia in Pediatric Patients on Chronic Angiotensin II Blocker Treatment

Prolonged postoperative vasoplegia is known to occur following cardiac surgery in patients on chronic angiotensin II receptor blocker (ARB) treatment in adults. The perioperative management of these drugs in the pediatric population is not well described and here we would like to highlight this fact. While ARBs are increasingly used in children and adolescents with hypertension, there is lack of data to guide optimal pre-surgical management in the pediatric age group. We report two cases of prolonged vasoplegia following cardiopulmonary bypass occurring in adolescent patients on chronic ARB therapy and the importance of cessation of these drugs preoperatively.

Valsartan decreases platelet activity and arterial thrombotic events in elderly patients with hypertension

BACKGROUND

Angiotensin type 1 receptor (AT 1 R) antagonists are extensively used for blood pressure control in elderly patients with hypertension. This study aimed to investigate the inhibitory effects of AT 1 R antagonist valsartan on platelet aggregation and the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.

METHODS

Two-hundred and ten patients with hypertension and aged > 60 years were randomized to valsartan (n = 140) or amlodipine (n = 70) on admission. The primary endpoint was platelet aggregation rate (PAR) induced by arachidonic acid at discharge, and the secondary endpoint was the rate of thrombotic events including brain infarction and myocardial infarction during follow-up. Human aortic endothelial cells (HAECs) were stimulated by angiotensin II (Ang II, 100 nmol/L) with or without pretreatment of valsartan (100 nmol/L), and relative expression of cyclooxygenase-2 (COX-2) and thromboxane B 2 (TXB 2 ) and both p38 mitogen-activated protein kinase (p38MAPK) and nuclear factor-kB (NF-kB) activities were assessed. Statistical analyses were performed by GraphPad Prism 5.0 software (GraphPad Software, Inc., California, USA).

RESULTS

PAR was lower after treatment with valsartan (11.49 ± 0.69% vs. 18.71 ± 2.47%, P < 0.001), associated with more reduced plasma levels of COX-2 (76.94 ± 7.07 U/L vs. 116.4 ± 15.89 U/L, P < 0.001) and TXB 2 (1667 ± 56.50 pg/ml vs. 2207 ± 180.20 pg/ml) (all P < 0.001). Plasma COX-2 and TXB 2 levels correlated significantly with PAR in overall patients (r = 0.109, P < 0.001). During follow-up (median, 18 months), there was a significantly lower thrombotic event rate in patients treated with valsartan (14.3% vs. 32.8%, P = 0.002). Relative expression of COX-2 and secretion of TXB 2 with concordant phosphorylation of p38MAPK and NF-kB were increased in HAECs when stimulated by Ang II (100 nmol/L) but were significantly decreased by valsartan pretreatment (100 nmol/L).

CONCLUSIONS

AT 1 R antagonist valsartan decreases platelet activity by attenuating COX-2/TXA 2 expression through p38MAPK and NF-kB pathways and reduces the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.

Psychopharmacological prescriptions for people with autism spectrum disorder (ASD): a multinational study

RATIONALE

Previous studies on psychotropic drugs prescribing in autism spectrum disorder (ASD) were from the USA or the UK. However, these studies may not be generalizable to other countries. There is a need to understand the extent of psychopharmacological prescribing for ASD treatment at a multinational level to identify areas of prescribing which lack evidence.

METHODS

We used the IMS Prescribing Insights database to investigate psychotropic drugs prescribing patterns for ASD treatment in children and adults in 2010-2012. Data were obtained from Europe (France, Germany, Italy, Spain and UK), South America (Mexico and Brazil), North America (Canada and USA) and Asia (Japan).

RESULTS

North American countries have the highest prescription rates, followed by the European and South American countries. Prescribing rates were higher in children compared to adults in individual countries. The most commonly prescribed drug for ASD was risperidone in young people (except in UK and Japan). In the UK, methylphenidate (34 %) was the most commonly prescribed for young people and haloperidol (44.1 %) in Japan. In adults, the most commonly prescribed drug class was antipsychotics and particularly risperidone (thioridazine and ziprasidone were the most prescribed antipsychotics in Brazil and USA, respectively).

CONCLUSION

There is variation in medication prescription for people with ASD among countries, which may be attributable to diagnostic criteria, clinical guidelines or health care systems. However, there is a lack of evidence of efficacy and safety for many psychotropic drugs prescribed for people with ASD. Research is needed to bridge the evidence gaps in prescribing.

Proliferative changes of renal arteriolar walls induced by administration of angiotensin II receptor blocker are frequent in juvenile rats

INTRODUCTION

Our previous study of angiotensin II receptor blocker (ARB) administration in rats induced unusual proliferative changes of smooth muscle cells in renal arteriolar walls. The present study examined if the incidence of the changes depended on the rats' age, and how long it would take to find changes.

MATERIALS AND METHODS

Six-week-old (juvenile spontaneous hypertensive rats (SHRs)+ARB group, n=15) and 20-week-old (adult SHRs+ARB group, n=10) male SHRs were fed a standard diet (0.4% NaCl) containing valsartan (10 mg/kg/day; Novartis Co.). Fifteen age-matched SHRs were studied as controls. After 4, 8, and 12 weeks, the rat kidneys were examined under light and electron microscopes and through immunohistochemical studies.

RESULTS

Extremely concentric proliferative changes in afferent arteriolar walls were frequently observed in the juvenile SHR+ARB group compared to the adult SHR+ARB group (48.7±6.8% vs 19.3±6.9%; p=0.0307) at the 12(th) week. Increased renin expression and arteriolar changes were found from the 4(th) week in the juvenile SHR+ARB group.

CONCLUSION

This study indicates that ARB administration induces unusual proliferative changes and a marked renin-producing cell increase in afferent arterioles more frequently in juveniles than adult rats. It is suggested that the treatment of ARB in juveniles might have a higher risk of changes in renal afferent arterioles.

Valsartan: in children and adolescents with hypertension

Valsartan is an oral angiotensin II subtype 1 receptor antagonist with well established antihypertensive efficacy in adults. It is now approved in the EU and the US for the treatment of hypertension in children and adolescents. In two, randomized, double-blind trials, a once-daily regimen of valsartan reduced the blood pressure (BP) of children and adolescents with hypertension. In one trial in hypertensive children and adolescents aged 6-16 years, significant dose-dependent reductions from baseline in mean sitting systolic BP (msSBP) were observed for recipients of valsartan following 2 weeks' treatment (primary endpoint). There were corresponding dose-dependent and significant reductions in mean sitting diastolic BP. Following 2 further weeks of treatment, the reduction in msSBP was maintained in patients who were re-randomized to continue receiving the same dosage of valsartan but not in those re-randomized to placebo. In the other trial in hypertensive children and adolescents aged 6-17 years, valsartan was no less effective than enalapril in reducing BP. Following 12 weeks' treatment, the least square mean reduction from baseline in msSBP (primary endpoint) in recipients of valsartan was noninferior to that in recipients of enalapril. In addition, the proportion of patients achieving an msSBP <95th percentile for age, sex, and height at week 12 was not significantly different between recipients of valsartan and enalapril (67% vs 70%). Treatment with valsartan for up to 52 weeks was well tolerated in children and adolescents with hypertension.