There is so far a lack of scientific evidence that glitazones are better than alternative therapies at reducing mortality or complications caused by blood vessel damage in people with type 2 diabetes. As long-term studies are lacking, reliable conclusions on the long-term benefit or harm of these oral antidiabetics are presently possible only to a limited extent. Available studies provide indications that patients could benefit from one of the two currently approved active substances (pioglitazone); however, these studies also provide indications of potential disadvantages, including an increased risk of heart failure. This is the conclusion of a report by the German Institute for Quality and Efficiency in Health Care (IQWiG), Cologne, which was published in January 2009 and for which an English-language summary is now available.
No antidiabetic of first choice
Glitazones improve insulin sensitivity in the adipose tissue, skeletal muscle, and liver. As a result, glucose uptake by the adipose tissue and muscle tissue increases, while the release of glucose from the liver is inhibited. However, glitazones, which are available as tablets, are not regarded as an antidiabetic of first choice and therefore have only limited approval in Europe. They are only allowed to be used as monotherapy if patients do not tolerate metformin or if other contraindications for the use of this drug exist.
In combination therapy, glitazones should only be prescribed if blood-glucose levels are insufficiently controlled by metformin or a sulfonylurea alone. A 3-drug therapy in combination with sulfonylurea and metformin is also possible: however, glitazones are only approved in this therapy regimen if a previous combination of sulfonylurea and metformin failed to achieve the desired success. Pioglitazone can also be used in combination with insulin.
Long-term use has not been sufficiently tested
The aim of the report, which was comm
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Institute for Quality and Efficiency in Health Care