Pioglitazone Is the Forgotten Diabetes Drug

Pioglitazone is the forgotten diabetes drug. This capsule, accessible as an affordable generic, has a robust impact on insulin resistance, reliably reduces blood sugar ranges, and improves cardiovascular outcomes. However fears over its unwanted side effects have largely sidelined pioglitazone as a kind 2 diabetes therapy. It’s not often mentioned and is barely prescribed to a slim minority of eligible sufferers.

These fears “are primarily based fully on misconceptions,” says Ralph DeFronzo, MD. “This can be a very, excellent drug.”

It will be tough to seek out an knowledgeable on diabetes treatment of larger stature than Dr. DeFronzo, the chief of diabetes at UT Well being San Antonio. In his storied profession, DeFronzo helped outline our fashionable understanding of insulin resistance, spearheaded the event and approval of metformin in the USA, and established the scientific foundation for the drug class of SGLT2 inhibitors.

DeFronzo believes that pioglitazone has been ignored by the medical neighborhood for all of the fallacious causes, and he desires to set the document straight. In his telling, there are hundreds of thousands of sufferers that would profit from pioglitazone, however clinicians are sadly hesitant to suggest the drug as a consequence of unfounded “unfavorable bias.”

What Is Pioglitazone?

Pioglitazone is a member of the thiazolidinedione (TZD) household of medicines that’s accredited for kind 2 diabetes. It’s generally bought underneath the model identify Actos, although additionally it is accessible as a generic. It’s a once-daily capsule.

The American Diabetes Affiliation explains that pioglitazone can “assist insulin work higher within the muscle and fats and cut back glucose manufacturing within the liver.”

Why Pioglitazone Is Distinctive Amongst Diabetes Medication

DeFronzo states that pioglitazone is “the one true drug which improves the insulin resistance in individuals with kind 2 diabetes.”

No different drug treats insulin resistance in the identical method. Regardless of well-liked understanding, DeFronzo explains, “metformin isn’t an insulin sensitizing drug. It could’t even get into the muscle, due to this fact it’s unattainable to be an insulin-sensitizing drug.” And whereas newer medication like GLP1 receptor agonists comparable to semaglutide (Ozempic) can enhance insulin resistance, they do it by selling weight reduction, not by instantly addressing its root trigger.

There are two central causes of kind 2 diabetes: insulin resistance, which makes the physique much less delicate to the hormone insulin, and beta cell dysfunction, which causes the physique to secrete much less insulin. The collision of these two issues — needing extra insulin and making much less of it — defines the development of diabetes.

“We have now a variety of medication that enhance beta cell operate, notably GLP1 receptor agonists, and people medication preserve getting higher and higher, however aside from pioglitazone, there isn’t any drug that corrects the underlying insulin resistance.”

DeFronzo believes that this makes pioglitazone a uniquely precious drug for kind 2 diabetes, particularly when utilized in mixture with different medicines. He prescribes it to his sufferers as a matter in fact, typically together with GLP1 receptor agonists, SGLT2 inhibitors, and/or metformin.

The Advantages of Pioglitazone

Pioglitazone is at the beginning a glucose-lowering drug. A 2010 assessment in Diabetes Care discovered that pioglitazone, at a reasonable dosage, “achieved an A1C discount of ∼1 p.c versus placebo,” a end result on par with metformin. It additionally carries a low danger of hypoglycemia, in contrast to insulin or sulfonylureas.

This capsule results in many vital secondary advantages, as effectively. A 2001 assessment discovered that the drug reduces triglycerides and will increase HDL ldl cholesterol (“good ldl cholesterol”); research additionally present that it decreases blood strain and should cut back the danger of kidney illness too.

Lastly, pioglitazone additionally seems to supply sturdy cardiovascular safety. A 2007 meta-analysis of 19 main trials and over 16,000 sufferers discovered that pioglitazone lowered the danger of stroke, myocardial infarction, and demise.

Pioglitazone’s Worrying Aspect Results

If pioglitazone is so nice, why did it ever fall out of favor with medical doctors? The reply is that “a grey cloud has hung over pioglitazone,” in response to DeFronzo. The drug is often believed to be related to a variety of unhealthy unwanted side effects. DeFronzo enumerated every of those results, and defined why he thought they have been misconceptions, one after the other.

Weight Acquire

Pioglitazone causes weight acquire. In keeping with a 2019 assessment, the typical TZD person might acquire 2.30 to 4.25 kilograms (kg) (5 to 9.4 kilos [lb]).

Weight acquire, usually talking, is nearly the very last thing you need within the setting of kind 2 diabetes. “We all know that weight acquire is unhealthy,” says DeFronzo, “and naturally it’s what’s driving the diabetes epidemic.”

However the weight acquire that pioglitazone causes has a “distinctive and paradoxical” impact, in response to DeFronzo:

“With pioglitazone, the extra weight you acquire, the larger the advance in insulin sensitivity. The extra weight that you just acquire, the larger the advance in beta cell operate. The extra weight you acquire, the larger the drop in blood strain, the larger the drop in triglycerides, the larger the rise in HDL ldl cholesterol. The extra weight you acquire, the much less probably that you just die!”

“It’s actuality. That is seen in each examine. We have now weight acquire, however the whole lot single factor that’s good appears to be getting higher.”

The load acquire related to pioglitazone, due to this fact, is “a purely beauty subject,” in response to DeFronzo. And at this time it may be simply counteracted with diabetes medication that create weight reduction, notably GLP1 receptor agonists like semaglutide (Ozempic) or tirzepatide (Mounjaro).

Coronary heart Failure

Pioglitazone causes coronary heart failure. This, understandably, worries clinicians.

And but, DeFronzo believes that the proof is totally clear that the drug creates solely good cardiovascular outcomes, not unhealthy ones: “It’s a really highly effective drug for decreasing cardiovascular occasions.”

A 2007 meta-analysis discovered that the danger of coronary heart failure elevated from 1.8 p.c (in a management group) to 2.3 p.c in these handled with pioglitazone, however “with out an related improve in mortality.”

In truth, the sufferers with coronary heart failure really had a stunning lower within the danger of mortality. DeFronzo goes over the main points in an article co-authored with Steven Nissen, MD, an eminent heart specialist with the Cleveland Clinic. And in smaller trials, pioglitazone has really proven a capability to enhance the operate of the guts in quite a lot of methods.

Different specialists agree. A 2021 assessment in Cardiovascular Diabetology concluded that this “neglected drug” gives “cardiovascular protecting potential, regardless of the danger of fluid imbalance in overt coronary heart failure.”

Fluid Retention

Pioglitazone could cause edema, or fluid retention, in some 5 to 10 p.c of customers, resulting in swelling within the toes, ankles, legs, or different elements of the physique.

Edema might be uncomfortable; it’s additionally related to quite a lot of unfavorable well being results, together with coronary heart failure and ailments of the lungs, liver, thyroid or kidneys. Nonetheless, there’s little or no proof linking the fluid retention attributable to pioglitazone with any vital unfavorable well being outcomes. When his personal sufferers expertise fluid retention, DeFronzo treats them with a diuretic.

Bladder Most cancers

Pioglitazone has been banned in Germany, France, and India as a consequence of an obvious danger of bladder most cancers. In the USA, the federal government appears considerably much less sure, with the U.S. Meals and Drug Administration (FDA) stating that it “could also be linked to an elevated danger of bladder most cancers.”

DeFronzo insists that that is all a grave error, principally primarily based on sloppy recruitment for one in all pioglitazone’s greatest assessments, the PROActive trial. This trial, briefly, enrolled a small variety of volunteers with blood of their urine who “most likely had bladder most cancers earlier than they started the examine,” in response to DeFronzo. Unluckily, most of them have been randomly positioned into the group of pioglitazone customers (versus the management group), creating an faulty affiliation between the medication and the illness.

After the affiliation was recognized within the PROActive trial, the FDA required pioglitazone’s maker to observe up with a long-term check of pioglitazone and bladder most cancers. That examine, revealed in 2015, concluded that “pioglitazone use was not related to a statistically vital elevated danger of bladder most cancers” however didn’t shut the door on the subject, calling for “additional investigation.”

A 2018 systematic assessment famous that the danger of bladder most cancers was not considerably elevated if one have been to exclude the controversial PROActive members who developed most cancers inside the first 12 months of therapy, however in the end concluded that there’s a “barely however considerably elevated danger of bladder most cancers.”

Takeda Prescribed drugs, the maker of pioglitazone (Actos), has paid billions to settle lawsuits associated to bladder most cancers, a authorized end result that no less than one diabetes knowledgeable decried as an injustice: “A lot for evidence-based medication.”


The popularity of pioglitazone additionally suffers as a consequence of affiliation with a distinct TZD, rosiglitazone (Avandia), which can trigger heart problems. Rosiglitazone was as soon as the best-selling diabetes drug on this planet, nevertheless it has been faraway from the market in many countries, and for years was solely bought with particular restrictions in the USA. Although the drug stays accessible in the USA at this time, gross sales have cratered as a result of fears.

“Individuals haven’t been in a position to separate the potential unfavorable results of rosiglitazone from the very, very, very optimistic results of pioglitazone,” DeFronzo says.

To underline his level, DeFronzo shares that his colleague Dr. Nissen, the only knowledgeable most answerable for drawing consideration to rosiglitazone’s potential harms, “makes use of pioglitazone as first-line remedy in his sufferers.” And, certainly, Nissen is on the document testifying to pioglitazone’s cardioprotective advantages.


Pioglitazone is a forgotten possibility for kind 2 diabetes administration. It’s the solely drug that instantly addresses insulin resistance, one of many root causes of diabetes, and it results in decrease A1C and improved cardiovascular and metabolic well being. It’s accessible as an affordable generic capsule.

Pioglitazone, nevertheless, carries a danger of regarding unwanted side effects, together with weight acquire, fluid retention, and coronary heart failure, particularly on the highest accredited doses. Paradoxically, these unfavorable results appear to be related to higher well being outcomes.

DeFronzo explains that his friends — different specialists at main educational hospitals — perceive the upsides of pioglitazone, however that few working towards clinicians do. And since the emblems on pioglitazone have expired, there’s little monetary incentive to rehabilitate its popularity.

DeFronzo argues that pioglitazone needs to be a part of the usual of take care of most individuals with kind 2 diabetes, and that it may be used to nice impact together with SGLT2s or GLP1 RAs, which will even assist counteract weight acquire: “I take advantage of it on a regular basis, particularly with newly identified kind 2 diabetes.”

Pioglitazone could also be inappropriate for sure sufferers; it’s important to debate your choices together with your healthcare supplier.

DeFronzo encourages Diabetes Every day readers to ask their medical doctors about pioglitazone: “They need to deliver it up with their medical doctors.”

“However the medical doctors, in all chance, are going to say no.”

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