German drugmaker Boehringer Ingelheim and the FDA have announced updates to the black box warning for Aptivus, a treatment for HIV, after it was linked to multiple fatal cases of brain hemorrhaging.

A recent letter to healthcare providers, distributed through the FDA's MedWatch program, said that Aptivus (tipranavir) was linked to 14 events of intracranial hemorrhaging (ICH), including eight fatalities, out of 6,840 HIV-1 infected individuals taking the drug.

The black box warning urges doctors to be cautious in prescribing Aptivus, which is co-administered with Abbot's Norvir, particularly for patients with chronic hepatitis B or hepatitis C co-infections.

Many of the patients experiencing ICH suffered from other medical conditions or were taking other drugs that may have caused or contributed to these events, the letter said. In higher doses and in extreme cases, Aptivus treatment led to bleeding in multiple organs and death.