Nesiritide (Natrecor)

Nesiritide is a real, FDA-approved synthetic version of human B-type natriuretic peptide (BNP) — and one of the clearest cautionary tales on this site of a drug whose real-world risk-benefit picture genuinely shifted after approval. Approved in 2001 on a real trial showing improved breathlessness in acute heart failure, it was followed in 2005 by two meta-analyses raising mortality and kidney-safety concerns, and then in 2011 by a very large, dedicated outcomes trial (ASCEND-HF, 7,141 patients) that found no confirmed excess mortality — but also no meaningful clinical benefit. Its use collapsed accordingly, for genuinely sound reasons.

What it is, and its real 2001 approval

Nesiritide is recombinant human B-type natriuretic peptide (BNP), identical in sequence to the natural hormone the heart releases under wall stress. It causes vasodilation and natriuresis (sodium/fluid excretion), theoretically relieving the congestion of acute heart failure. FDA approved it (as Natrecor, Scios) in 2001 for intravenous use in patients hospitalized with acutely decompensated heart failure, based primarily on hemodynamic improvement and improved dyspnea in its pivotal trial program.

The 2005 safety scare

In 2005, Sackner-Bernstein and colleagues published two separate meta-analyses of existing smaller randomized trials. One, in Circulation (March 2005, 5 trials, 1,269 patients), found nesiritide at FDA-approved doses increased the risk of worsening renal function versus non-inotrope control therapy. The other, in JAMA (April 2005, 3 trials, 862 patients), found 30-day death in 7.2% (35/485) of nesiritide patients versus 4.0% (15/377) of controls — a risk ratio of 1.74 (95% CI 0.97-3.12, p=0.059), a trend that did not reach conventional statistical significance but was concerning enough to trigger an FDA review and a sharp, near-immediate drop in real-world nesiritide use.

ASCEND-HF: the trial that actually settled it

The Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (O'Connor et al., N Engl J Med 2011;365:32-43, PMID 21732835) randomized 7,141 patients hospitalized with acute heart failure across 398 centers. Self-reported dyspnea improvement at 6 and 24 hours was statistically significant but not judged clinically important; nesiritide neither increased nor decreased 30-day death or heart-failure rehospitalization; it did not worsen renal function; but it nearly doubled the rates of both symptomatic and asymptomatic hypotension.

A real case study in risk-benefit shifting after approval

Nesiritide's arc is genuinely instructive: approved on a real if narrow symptom endpoint, followed by a real safety alarm from pooled smaller-trial data that didn't reach significance, followed by a large dedicated trial that neither confirmed the alarm nor demonstrated meaningful benefit. Nesiritide remains FDA-approved and still marketed, but current heart-failure guidelines generally do not recommend routine use — a real drug whose place in medicine shrank almost entirely because of what post-approval trials, not any single scandal, actually showed.