Valsartan in the treatment of hypertension

Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma

A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML), olmesartan medoxomil (OLM), valsartan (VAL), and hydrochlorothiazide (HCT) in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combination I) and AML, VAL, and HCT (combination II). The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v) was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1-18.5  μ g/mL, 0.4-25.6  μ g/mL, 0.3-15.5  μ g/mL, and 0.3-22  μ g/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME) ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances.

Efficacy and safety of valsartan in hypertensive Taiwanese patients: post-marketing surveillance study

OBJECTIVE

To evaluate the efficacy and safety of valsartan in Taiwanese patients with essential hypertension.

METHODS

This 12-week multi-center, open-label, observational, post-marketing surveillance study enrolled 2046 hypertensive patients who were prescribed valsartan 80 or 160 mg as monotherapy or in combination with other antihypertensives based on clinical judgment. The primary endpoint was the incidence rate of dizziness with valsartan 160 mg monotherapy or combination therapy at Week 4. Secondary endpoints included the blood-pressure-lowering efficacy and the overall safety and tolerability of valsartan at Weeks 4 and 12.

RESULTS

The monotherapy and combination groups had comparable baseline characteristics. At Week 4, monotherapy was found non-inferior to combination for incidence rate of dizziness (monotherapy, 9.25%; combination, 10%; difference in incidence of dizziness, 0.75%; 95% CI - 0.61% to 2.12%; non-inferiority margin, -1.33%;WaldTest approach). Greater blood pressure (BP) reduction was noted atWeek 12 than atWeek 4.The antihypertensive effect was greater with combination therapy and the 160-mg dose. BP control (systolic <140 mmHg or diastolic <90 mmHg) was achieved in 80-90% patients.Valsartan was well tolerated; most commonly reported adverse events included dizziness, headache, constipation and cough.

CONCLUSION

Valsartan is an effective treatment option for essential hypertension in Taiwanese patients.

Simultaneous determination of fixed dose combination of nebivolol and valsartan in human plasma by liquid chromatographic-tandem mass spectrometry and its application to pharmacokinetic study

A rapid, sensitive and accurate liquid chromatographic-tandem mass spectrometry method is described for the simultaneous determination of nebivolol and valsartan in human plasma. Nebivolol and valsartan were extracted from plasma using acetonitrile and separated on a C18 column. The mobile phase consisting of a mixture of acetonitrile and 0.05 mM formic acid (50:50 v/v, pH 3.5) was delivered at a flow rate of 0.25 ml/min. Atmospheric pressure ionization (API) source was operated in both positive and negative ion mode for nebivolol and valsartan, respectively. Selected reaction monitoring mode (SRM) using the transitions of m/z 406.1-->m/z 150.9; m/z 434.2-->m/z 179.0 and m/z 409.4-->m/z 228.1 were used to quantify nebivolol, valsartan and internal standard (IS), respectively. The linearity was obtained over the concentration range of 0.01-50.0 ng/ml and 1.0-2000.0 ng/ml and the lower limits of quantitation were 0.01 ng/ml and 1.0 ng/ml for nebivolol and valsartan, respectively. This method was successfully applied to the pharmacokinetic study of fixed dose combination (FDC) of nebivolol and valsartan formulation product after an oral administration to healthy human subjects.

The angiotensin receptor antagonist valsartan: a review of the literature with a focus on clinical trials

Valsartan is an angiotensin receptor antagonist that specifically blocks the angiotensin II type 1 receptors. It is an effective and well-tolerated once-daily antihypertensive agent, with a tolerability profile similar to placebo. A recent series of large-scale clinical trials have shown the benefits of valsartan in disease states beyond hypertension. Based on the results of the Val-HeFT (Valsartan in Heart Failure Trial) and VALIANT (Valsartan in Acute Myocardial Infarction Trial) studies, valsartan is indicated for use in patients with heart failure and in patients post-myocardial infarction. Recently, in the VALUE (Valsartan Antihypertensive Long-term Use Evaluation) trial, valsartan was no more cardioprotective than calcium channel blockers, but was shown to reduce the risk of developing new-onset diabetes in hypertensive patients at high risk of cardiac events compared with calcium antagonist treatment. In diabetic patients with microalbuminuria, valsartan has been shown to have benefits beyond those attributable to blood pressure lowering alone.