Following the regulators' moves against GlaxoSmithKline's Avandia, industry observers have been reacting to the news and considering the impact of suspension in Europe and further restrictions in the USA.

Steve Nissen of the Cleveland Clinic and a critic of Avandia (rosiglitazone) who authored a much-publicised meta-analysis linking the drug to a 43% increased risk of heart attack in May 2007, is pretty pleased with the outcomes. He told the Wall Street Journal that the US Food and Drug Administration's decision to keep Avandia on the market with severe restrictions is "a reasonable course of action and compromise. It will limit 99% of its use".

He added that doctors will be forced to document in detail that their patients are benefiting from Avandia and patients "will have to read and sign documents saying they understand the cardiovascular risks". That is "such a barrier to its use", Dr Nissen said, and between the FDA and the European Medicines Agency "it essentially means the drug is gone".

Other observers believe the FDA has not gone far enough and Sidney Wolfe, director of the influential consumer organisation's Public Citizen's Health Research Group, said the agency has "again caved to industry pressure". He added that "too many people could still be exposed to this dangerous product", arguing that the FDA "should have acted with its European counterpart and outright banned Avandia from the market".

Dr Wolfe went on to say that more than three years ago at an FDA advisory committee meeting, Public Citizen urged the FDA to ban Avandia. "Since then, 9 million prescriptions for the drug have been filled in the USA. This means that, just in the past three years alone, tens of thousands more patients have needlessly suffered hospitalisations for heart failure or deaths" than would have had they taken Takeda's Actos (pioglitazone), "a comparable, but safer drug".

Speaking of Actos, Takeda issued a statement saying that it offers "an established safety profile regarding the risk of CV events", saying that controlled clinical studies, conducted over the past 11 years in more than 20,000 patients globally, "show no evidence that Actos is associated with an increased risk of heart attack, stroke or death".

Analysts believe that Takeda will benefit from Avandia's travails but possibly only in the short-term as Actos goes off-patent in the USA in January next year. BMO Capital Markets’ Robert Hazlett believes that doctors are more likely to prescribe Merck & Co's dipeptidyl peptidase-4 (DPP-4) inhibitor Januvia (sitagliptin).

Others believe that the glucagon-like peptide-1 (GLP-1) analogues, namely Novo Nordisk's Voctoza (liraglutide) and Eli Lilly/Amylin's Byetta (exenatide). will be the main beneficiaries, which have been shown to reduce weight while lowering blood sugar.