New Aids drugs launched in Britain

The first of a new class of Aids drugs which can significantly improve patients' chances of survival was launched in Britain yesterday after winning EU-wide approval. Ritonavir, a "protease inhibitor", attacks Aids in a different way to existing drugs. It stops the virus's attempts to spread in the final stages of its life cycle; existing drugs work in the early stages.

Trials show that when the virus comes under double attack from both protease inhibitors and previously available treatments such as AZT, the amount of virus circulating in patients' bodies is reduced to undetectable levels. Patients' immune systems are also boosted. The chances of the disease progressing - and the risk of death - are therefore significantly reduced.