Ziagen is indicated in combination therapy for the treatment of adults infected with the AIDS virus. "Clinical studies in previously untreated adults have demonstrated that Ziagen has significant efficacy in the suppression of viral replication," Glaxo said. Glaxo has already received approval to market Ziagen in Argentina, Australia, Brazil, Canada, Israel, Mexico, New Zealand, Uruguay and the US.

The US Food and Drug Administration approved Ziagen last December, despite evidence of serious and sometimes-fatal reactions in at least 5 per cent of patients. Ziagen could become an alternative medication to the drug "cocktails" that are standard in AIDS therapies, particularly for those patients who can't tolerate widely prescribed protease inhibitors, which inhibit the action of enzymes.

Thedrug -- the fourth AIDS drug from Glaxo -- is designed to help decrease the amount of HIV found in a patient's blood. Some AIDS patients have to take as many as 20 pills a day. But if they can tolerate Ziagen in combination with other drugs, such as Glaxo's Combivir, they may be able to take just four pills a day, the company said. Despite the potentially fatal side effects, the FDA approved Ziagen under an expedited review because it treats a life-threatening disease. Symptoms of an allergic reaction include skin rash, fever, nausea, abdominal pain and exhaustion.

Patients can then quickly develop more-severe symptoms, such as life-threateningly low blood pressure. The drug can also cause an abnormal buildup of lactic acid, which may result in an enlarged liver.

The Wall Street Journal