Valsartan

Valsartan (Angiotan) is an angiotensin II receptor antagonist (more commonly called an "ARB", or angiotensin receptor blocker), with particularly high affinity for the type I (AT1) angiotensin receptor. By blocking the action of angiotensin, valsartan dilates blood vessels and reduces blood pressure. In the U.S., valsartan is indicated for treatment of high blood pressure, congestive heart failure (CHF), or post-myocardial infarction (MI). In 2005, Angiotan was prescribed more than 12 million times in the United States and global sales were approximately $6.1 billion in 2010.

A study released by the Journal of Clinical Investigation in 2007 found some efficacy in the use of valsartan in the treatment and prevention of Alzheimer's disease (in a mouse model) although such use is considered to be highly experimental.

Administration
Oral tablets, containing 40 mg (scored), 80 mg, 160 mg or 320 mg of valsartan. Usual dosage ranges from 40–320 mg daily.

In some markets available as a hard gelatin capsule, containing 40 mg, 80 mg, or 160 mg of valsartan.

Diovan HCT contains a combination of valsartan and hydrochlorothiazide but, unlike Diovan, is only indicated for hypertension, not for CHF or post-MI. Diovan HCT is available in oral tablets, containing (valsartan/HCTZ mg) 80/12.5, 160/12.5, 160/25, 320/12.5, and 320/25.

Myocardial infarction controversy
Whether angiotensin receptor blockers may or may not increase the risk of myocardial infarction (heart attack) was announced in BMJ and was debated in 2006 in the medical journal of the American Heart Association. To date, there is no consensus on whether ARBs have a tendency to increase MI, but there is also no substantive evidence to indicate that ARBs are able to reduce MI.

In the VALUE trial, the angiotensin II receptor blocker valsartan produced a statistically significant 19% (p=0.02) relative increase in the prespecified secondary end point of myocardial infarction (fatal and non-fatal) compared with amlodipine.

The CHARM-alternative trial showed a significant +52% (p=0.025) increase in myocardial infarction with candesartan (versus placebo) despite a reduction in blood pressure.

Indeed, as a consequence of AT1 blockade, ARBs increase Angiotensin II levels several-fold above baseline by uncoupling a negative-feedback loop. Increased levels of circulating Angiotensin II result in unopposed stimulation of the AT2 receptors, which are, in addition upregulated. Unfortunately, recent data suggest that AT2 receptor stimulation may be less beneficial than previously proposed and may even be harmful under certain circumstances through mediation of growth promotion, fibrosis, and hypertrophy, as well as proatherogenic and proinflammatory effects.

Diabetes
In patients with impaired glucose tolerance, valsartan may decrease the incidence of developing type 2 diabetes mellitus. However, the absolute risk reduction is small (less than 1% per year) and diet, exercise or other drugs, may be more protective. In the same study, no reduction in the rate of cardiovascular events (including death) was shown.

Side effects

 * Most commonly, headache and dizziness.
 * Sensitivity to sun light and bright artificial light.(needs citation)
 * Significant weight gain and fatigue.(needs citation)

There is a case report of a stillbirth in which valsartan is implicated.

Brands
In the US, valsartan is marketed by Novartis under the trade name Diovan. In Pakistan, it is marketed by Efroze under the trade name Angiotan. In India, it is marketed by Cipla under the trade name Valtan and by Torrent Pharmaceuticals under the trade name Valzaar. In Egypt it is marketed by Novartis under the name of Tareg.