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Treatment for Hyponatremia

FDA Issues Approvable Letter for Yamanouchi's Investigational Hyponatremia Treatment Conivaptan Hydrochloride Injection

PARAMUS, N.J., December 01, 2004 -- Yamanouchi Pharma America, Inc., a subsidiary of Yamanouchi Pharmaceutical Co., Ltd., today announced that the U.S. Food and Drug Administration (FDA) has issued an approvable letter for conivaptan hydrochloride injection, the company's investigational treatment for hyponatremia. The letter outlines the conditions for marketing approval, which include a submission of additional safety data. If approved, conivaptan is expected to be the first drug specifically indicated for the treatment of hyponatremia, a potentially life-threatening condition that occurs when the body's blood sodium level falls significantly below normal.

Akihiko Matsubara, President and Chief Operating Officer of Yamanouchi Pharma America, Inc., said, "We are pleased with the approvable designation, and we will work closely with the FDA to bring conivaptan to market as quickly as possible. If approved, we believe that conivaptan will provide another alternative in the management of hyponatremia, a potentially serious condition for which there is currently no approved treatment."

Conivaptan is the second drug Yamanouchi hopes to introduce to the market in the United States.

About Conivaptan
Developed by Yamanouchi, conivaptan is a novel drug that demonstrated in clinical trials the ability to restore normal sodium levels in patients with hyponatremia. Although there are no drug therapies approved for hyponatremia, current treatments include fluid restriction, diuretics and hypertonic saline solution.

About Hyponatremia
Hyponatremia is estimated to affect 1 percent to 4 percent of hospitalized patients in the United States each year.1,2 Congestive heart failure, advanced renal failure, hypothyroidism, chronic hypertension and syndrome of inappropriate antidiuretic hormone (SIADH) are frequently causes of hyponatremia. Dilutional hyponatremia, the most common form of the condition, occurs when retained water dilutes serum sodium content. While many patients with hyponatremia have no symptoms, severe cases are medical emergencies that can result in swelling of the brain, respiratory arrest and death.

About Yamanouchi Pharma America, Inc.
As the U.S. subsidiary of Yamanouchi Pharmaceutical Co., Ltd., Yamanouchi Pharma America, Inc. is dedicated to developing and delivering innovative therapeutic treatment options for unmet medical needs. Drawing upon the parent company's over 80-year heritage of research excellence and pioneering product development, Yamanouchi Pharma America has established the goal of becoming a leading pharmaceutical company in the United States.

The FDA recently approved VESIcare (solifenacin succinate) for the treatment of overactive bladder with symptoms of urgency, frequency, and urge incontinence. VESIcare will be co-promoted by Yamanouchi and GlaxoSmithKline. Yamanouchi also has a number of exciting and innovative investigational compounds currently in clinical development.


  1. Tierney WM, Martin DK, Greenlee MC, Zerbe RL, McDonald CJ.
    The prognosis of hyponatremia at hospital admission.
    J Gen Intern Med 1986; 1:380-385.
  2. Anderson RJ, Chung HM, Kluge R, Schrier RW.
    Hyponatremia: a prospective analysis of its epidemiology and the pathogenic role of Vasopressin.
    Ann Int Med 1985; 102:164-168.

Posted: December 2004

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