Category C—Except for the reports below in which the naltrexone was discontinued very early in gestation, no other references describing the use of the agent during human pregnancy have been located. Although naltrexone did not produce gross structural abnormalities in any of the animal studies, it did alter some opioid receptors in the brain that appeared to have long-lasting consequences. This potential for behavioral alteration in humans cannot be assessed because of the lack of data, but concern is warranted.
Limited Human Data—Probably Compatible
Dose adjustment not generally necessary for mild impairment; not studied in patients with moderate to severe renal impairment
Hepatically metabolized; contraindicated in acute hepatitis or liver failure; dose adjustment not generally necessary for mild impairment; not studied in patients with severe hepatic impairment; has potential to cause hepatocellular injury when given in excessive doses