By Truman Lewis
ConsumerAffairs.com
September 13, 2007
New research presents possibly alarming findings about the long-term effects of one popular diabetes drug and reassuring findings about another.
The first study found that one of the drugs, Actos (pioglitazone), significantly reduces the risk of heart attack, stroke and death but slightly increases the risk for serious heart failure.
Another study found that patients taking a second drug, Avandia, appear to be at increased risk for a heart attack or heart failure and the researchers said regulators should seriously consider whether the drug should be allowed to remain on the market.
The studies were both so-called meta-analyses -- large-scale mathematical reviews of previous studies. Such overview studies often find long-term effects that are overlooked in shorter-term, highly-focused clinical studies. The latest studies were published in today's issues of JAMA.
Avandia
The Avandia study finds patients with type 2 diabetes or impaired glucose tolerance who take the medication Avandia (rosiglitazone) appear to be at increased risk for a heart attack or heart failure.
Sonal Singh, M.D., and colleagues from the Wake Forest University School of Medicine, Winston-Salem, N.C., reviewed research to examine the risk of heart attack, heart failure and cardiovascular death with long-term Avandia use.
There have been recent reports of serious adverse events with Avandia use, but information available to clinicians on the magnitude and public health impact of these events has been limited.
The researchers compiled data from four randomized trials that included 14,291 patients Follow-up for these studies was 1-4 years.
The pooled data from the trials indicated that Avandia, compared with controls, significantly increased the risk of heart attack by 42 percent (94 of 6,421 patients who received Avandia vs. 83 of 7,870 patients who received control therapy) and doubled the risk of heart failure (102 of 6,421 patients vs. 62 of 7,870 patients). Use of Avandia was not associated with a significant increase in risk of cardiovascular death.
Our findings have potential regulatory and clinical implications. These data suggest a reversal of the benefit-to-harm balance for Avandia present at the time of approval. Thus, currently there appear to be much safer treatment alternatives.
Regulatory agencies ought to reevaluate whether Avandia should be allowed to remain on the market. Health plans and physicians should not wait for regulatory actions. They should avoid using Avandia in patients with diabetes who are at risk of cardiovascular events, especially since safer treatment alternatives are available, the authors conclude.
Actos
In the Actos study, A. Michael Lincoff, M.D., and colleagues at the Cleveland Clinic, conducted a meta-analysis of research to evaluate the effect of Actos on the incidence of ischemic cardiovascular complications for patients with type 2 diabetes.
The analysis included 19 randomized trials and 16,390 patients. Duration of the use of the medication use ranged from 4 months to 3.5 years.
The researchers found that heart attack, stroke or death occurred in 375 (4.4 percent) of 8,554 patients receiving Actos and 450 (5.7 percent) of 7,836 patients treated with control therapy, an 18 percent relative reduction.
These outcomes were all reduced by a similar magnitude with Actos treatment. Serious heart failure was reported in 200 (2.3 percent) of Actos-treated patients and 139 (1.8 percent) of control patients.
These findings suggest that the net clinical cardiovascular benefit with Actos therapy is favorable, with an important reduction in irreversible ischemic events that is not attenuated by the risk of more frequent heart failure complications, the authors write.
