The US Food and Drug Administration cleared several generic versions of GlaxoSmithKline's anti-HIV drug Retrovir (zidovudine), opening the way to cheaper antiretroviral treatment for the million or more people in the country infected with the virus.

Following the expiry of GSK's patents on zidovudine [[19/09/05e]], the FDA has been able to approve zidovudine tablets manufactured by India's Ranbaxy Laboratories and Aurobindo Pharma and US drugmaker Roxane Laboratories, as well as an oral solution formulation of the drug made by Aurobindo.

Health and Human Services secretary Mike Leavitt said: "Generic products help reduce costs to patients and for the first time this antiretroviral drug will be available as a generic paediatric dosage form." Previously, HIV patients had been able to access some of these medications from overseas under the USA's Emergency Plan for Aids Relief

Retrovir has been a stalwart of combination drug treatment for HIV infection for years, but its commercial importance to GSK has markedly diminished from its peak of £250 million a year in the mid-1990s, as sales of the company's combination products Combivir (zidovudine and lamivudine) and Trizivir (zidovudine, lamivudine and abacavir) have escalated. In the first half of the year Retrovir brought in just £21 million to GSK, £8 million from the USA.