Efficacy/Safety of Olmesartan Medoxomil versus Losartan Potassium in Patients by Stage 1 or 2 Hypertension

Is the newest angiotensin-receptor blocker azilsartan medoxomil more efficacious in lowering blood pressure than the older ones? A systematic review and network meta-analysis

Angiotensin‐receptor blockers are often considered insufficiently efficacious in reducing blood pressure. However, newer angiotensin‐receptor blockers may be more effective than the older ones. A network meta‐analysis was performed to compare the efficacy of various angiotensin‐receptor blockers in reducing office and ambulatory blood pressure in hypertensive patients. Relevant literature was searched from English and Chinese databases for randomized controlled trials involving angiotensin‐receptor blockers in hypertension. Efficacy variables included systolic and diastolic blood pressure either in the office or on ambulatory blood pressure monitoring. Absolute blood pressure reductions at 6‐12 weeks of treatment and their credible intervals were reported. A total of 34 publications provided adequate data for analysis (n = 14 859). In 28 studies on office systolic blood pressure (n = 12 731), against the common comparator valsartan 80 mg, the differences in systolic blood pressure were in favor of azilsartan medoxomil (20‐80 mg), irbesartan (300 mg), olmesartan (20‐40 mg), telmisartan (80 mg), and valsartan (160‐320 mg), but not candesartan (8‐16 mg), losartan (50‐100 mg), irbesartan (150 mg), olmesartan (10 mg), and telmisartan (40 mg). The ranking plot shows that azilsartan medoxomil 80 mg had a possibility of 99% being the best in the class. Similar results were observed for office diastolic blood pressure and from 13 studies for 24‐hour ambulatory systolic and diastolic blood pressure. In conclusion, angiotensin‐receptor blockers had different blood pressure lowering efficacy. The newest angiotensin‐receptor blocker azilsartan medoxomil at the dose of 80 mg seemed to be most efficacious in reducing both systolic and diastolic blood pressure in the office and on ambulatory measurement.

A literature review to evaluate the clinical and economic value of olmesartan for the treatment of hypertensive patients

The objective of the present study was to systematically review the clinical and economic outcomes of olmesartan as monotherapy or in combination with other antihypertensive agents in the treatment of hypertension. A literature search was performed using PubMed and the Cochrane library until December 2015, with no limit on publication date. Eligible studies were selected using predetermined inclusion and exclusion criteria, limiting articles to those published in the English language. Background information of the study, participants' characteristics and study outcomes were collected. Meta-analysis of data was not performed. Fifty-five studies were included, of which fifty investigated the clinical efficacy of olmesartan and five the cost-effectiveness of olmesartan. In general results from clinical trials evaluating the efficacy of olmesartan as monotherapy and as combination therapy demonstrated that olmesartan provided better antihypertensive blood pressure-lowering efficacy and was generally well tolerated compared with other antihypertensive agents. Results from economic evaluations indicated that olmesartan may be more cost-effective than other ARBs such as losartan, valsartan, irbesartan and candesartan, having the potential of decreasing the overall medical costs of care for patients with hypertension. Evidence from the present systematic review confirms the antihypertensive efficacy and good safety profile of olmesartan both as monotherapy and as combination therapy. Olmesartan was also found to be cost-effective compared with other ARBs, though this area has yet relatively poor evidence and needs to further be explored.

Angiotensin-(1-7)/Mas axis modulates fear memory and extinction in mice

Inappropriate defense-alerting reaction to fear is a common feature of neuropsychiatric diseases. Therefore, impairments in brain circuits, as well as in molecular pathways underlying the neurovegetative adjustments to fear may play an essential role on developing neuropsychiatric disorders. Here we tested the hypothesis that interfering with angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis homeostasis, which appears to be essential to arterial pressure control, would affect fear memory and extinction. Mas knockout (MasKO) mice, in FVB/N background, showed normal cued fear memory and extinction, but increased freezing in response to context. Next, as FVB/N has poor performance in contextual fear memory, we tested MasKO in mixed 129xC57BL/6 background. MasKO mice behaved similarly to wild-type (WT), but memory extinction was slower in contextual fear conditioning to a weak protocol (1CS/US). In addition, delayed extinction in MasKO mice was even more pronounced after a stronger protocol (3CS/US). We showed previously that Angiotensin II receptor AT1 antagonist, losantan, rescued object recognition memory deficit in MasKO mice. Here, losartan was also effective. Memory extinction was accelerated in MasKO mice after treatment with losartan. In conclusion, we showed for the first time that Ang-(1-7)/Mas axis may modulate fear memory extinction. Furthermore, we suggest MasKO mice as an animal model to study post-traumatic stress disorder (PTSD).