When used to treat ventilator-associated pneumonia, the antibacterial drug doripenem is linked to a greater risk of mortality and lower clinical cure rates compared with imipenem and cilastatin for injection, according to a drug safety communication issued by the Food and Drug Administration.
Doripenem, an intravenous penem antibacterial drug marketed as Doribax, is not approved to treat any type of pneumonia. A warning about increased mortality in patients with ventilator-associated pneumonia (VAP), for which the use of doripenem is unapproved, has been added to the drug’s label. In a statement posted on March 6, the FDA recommended that health care professionals "consider whether the benefits of Doribax treatment are likely to exceed its potential risks in patients who develop pneumonia while on ventilators."
The safety communication is based on an FDA analysis of a 3-year study comparing 7 days of treatment with doripenem to 10 days of treatment with imipenem and cilastatin in patients with VAP. All-cause mortality over 28 days was 23% among those treated with doripenem, compared with 16.7% among those treated with imipenem and cilastatin. Clinical cure rates also were lower in the doripenem-treated patients in the study, which was stopped prematurely in 2011.
The statement adds that doripenem, approved in 2007, "is still considered safe and effective" for treating adults with complicated intra-abdominal infections and complicated urinary tract infections, including pyelonephritis, which are FDA-approved indications.
In January 2012, the FDA issued a statement about the prematurely terminated study.
The revised doripenem label is available on the FDA website. The label change was made in January. Doripenem is manufactured by Shionogi.
Imipenem and cilastatin for injection is marketed as Primaxin in the United States.
Serious adverse events associated with doripenem should be reported to the FDA’s MedWatch program at 800-332-1088 or www.fda.gov/medwatch/.