The US Food and Drug Administration has concluded that Doribax (doripenem), an antibacterial drug that has been used to treat patients who develop pneumonia while on ventilators, carries an increased risk of death and lower clinical cure rates compared to use of imipenem and cilastatin for injection.

Based on its analysis of data from a three-year clinical trial that was prematurely stopped in 2011 due to these safety concerns, the FDA have approved changes to the Doribax drug label that describe these risks.

Doribax, which is manufactured by Shionogi Pharma Inc, is not approved to treat any type of pneumonia, and the revised label also includes a new warning about this unapproved use.

Health care professionals should consider whether the benefits of Doribax treatment are likely to exceed its potential risks in patients who develop pneumonia while on ventilators, according to the FDA.

The revised Doribax drug label is available here.

In the clinical trial that was stopped early, patients with ventilator-associated bacterial pneumonia received either 7-day Doribax treatment or 10-day treatment with imipenem and cilastatin, another antibacterial drug.

In the intent-to-treat population, the 28-day all-cause mortality was higher in the Doribax arm (23.0%; n=31/135) than in the imipenem and cilastatin arm (16.7%; n=22/132). Clinical cure rates were also lower in the Doribax arm.

The FDA noted that Doribax is still considered safe and effective for its FDA-approved indications: treatment of adults with complicated intra-abdominal infections and complicated urinary tract infections, including kidney infections called pyelonephritis.