Abbott Reports Production Problems For Norvir

Abbott Laboratories has reported that it is having difficultiesmaintaining production of its HIV protease inhibitor Norvir (ritonavir). The problems are related to its capsule formulation of the antiretroviral.

"We have encountered an undesired formation of a Norvir crystalline structure that affects how the capsule form of Norvir dissolves," commented Arthur Higgins, senior vice president for pharmaceutical operations at Abbott. Although the problem has been identified, to date the company has been unable to come up with a solution.

Abbott stressed that capsules already in circulation are not affected, but there will be shortages and an interruption in supply of the product. Given the seriousness of interrupting treatment in highly-active antiretroviral therapy (which could be associated with the development of resistance and ultimately treatment failure), Abbott is planning to manufacture Norvir in a substitute oral solution so that patients on the drug can maintain their supply. It is estimated that 60,000-70,000 people with HIV are taking the drug.