Public statement on supply of Norvir hard capsules
News
The protease inhibitor Norvir (ritonavir) was authorised under the centralised procedure on 26 August 1996 for the treatment of HIV infection, and is available in the European Union (EU) as a hard capsule 100 mg and an oral solution 80 mg per ml.
On 23 July 1998 Abbott Laboratories informed the European Medicines Agency that difficulties were being encountered in the manufacture of the hard capsule. The following is a summary of the key points of the problem as outlined by Abbott:
A series of recent production batches of Norvir hard capsules have failed the approved test for dissolution, and therefore have not been released for marketing.
Internal investigations as to the reasons for this failure revealed the presence of a new crystalline form of ritonavir, which would affect the way it dissolves, and possibly its subsequent absorption in the body.
However, all supplies of Norvir hard capsules that have been released onto the European Union market have so far passed the approved test for dissolution at the time of manufacture. (In addition, Abbott Laboratories examined retained samples from a number of marketed batches of hard capsules and found no evidence of this unwanted crystalline form.)
On the basis of available information the problems described above do not affect Norvir products currently supplied in the EU. Therefore, patients are advised not to stop taking Norvir hard capsules, and should continue as usual, in accordance with their physician's prescription.
Since Abbott cannot resolve this problem at the present time, Norvir hard capsules may become unavailable for prescription in the EU by mid-August 1998.
The resulting lack of Norvir hard capsules may be compensated by the use of Norvir oral solution. Abbott has confirmed that a sufficient supply of the oral solution will be available to meet any increase in demand in the EU. The oral solution is bioequivalent to the hard capsule formulation, meaning they both have the same chemical properties and anti-HIV activity. The recommended 600 mg twice daily dosage of ritonavir corresponds to 7.5 ml twice daily of the oral solution.
However, since it is imperative that ongoing antiretroviral therapy should not be interrupted, patients should seek advice from their prescribing physicians in order to maintain adequate treatment. Other treatment options may need to be considered by the prescribing physician for the treatment of HIV infected patients. Such options include use of the following protease inhibitor medicinal products, which have been granted a marketing authorisation in the EU:
- Crixivan (indinavir) capsules 200 mg and 400 mg;
- Viracept (nelfinavir) oral powder 50 mg/g and tablets 250 mg;
- Invirase (saquinavir) hard capsules 200 mg.
In all cases, to avoid any interruption in currently prescribed therapy, patients should consult with their prescribing physicians.