Actos (Pioglitazone)

Actos is a prescription diabetes medication used to treat adults with type 2 diabetes. It works by lowering blood sugar levels through its effects on insulin production and sensitivity.

Takeda Pharmaceuticals America Inc. makes two additional versions of the drug that combine the active ingredient pioglitazone with metformin (another diabetes medication): Actoplus Met and Actoplus Met XR (extended release).

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Does Actos have a generic name?

Actos is the brand name for pioglitazone which belongs to the thiazolidinedione class of drugs. Thiazolidinediones are used to control blood sugar levels in patients with type 2 diabetes by improving how the cells respond to insulin.

Insulin is a hormone produced by the pancreas that helps regulate blood sugar levels in the body. People with type 2 diabetes respond poorly to insulin or they become resistant to it. Over time, they may have trouble producing enough insulin.

Thiazolidinedione drugs activate certain genes inside fat cells which tell the cells to break fats down into fatty acids and glycol­esterol which can then enter the bloodstream. This improves insulin sensitivity with more blood sugar entering the cells for the body to use as energy.

What does Actos treat?

Actos should be used in combination with diet and exercise strategies to help patients with type 2 diabetes manage their condition more effectively.

Your doctor may prescribe Actos alone or with other diabetes medications depending on how well your body normally controls blood sugar.

How do you take Actos?

Take Actos once a day either with or without food. You should only take Actos as prescribed by your doctor.

The initial dose starts at 15mg (or 30mg)¹, but some people may need a higher dose. Your doctor can increase the dosage by 15mg up to a maximum dosage of 45mg per day.

Actos comes in the following strengths²:

  • 15mg 

  • 30mg

  • 45mg

Store Actos at 25°C (77°F) in a dry place out of sunlight.

How effective is Actos?

The effectiveness of Actos depends on many factors, including your age, weight, health history, lifestyle habits, and response to treatment. You will be monitored while taking Actos so your doctor can determine if your treatment plan needs adjustment.

Potential side effects of Actos

The most common side effect reported during Actos clinical studies is upper respiratory tract infection, followed by headache, sinus infection, and muscle pain.

Other reported side effects include:

  • Diarrhea

  • Dizziness

  • Back pain

  • Swelling

  • Rapid weight gain

  • Abdominal discomfort

Actoplus Met can cause the same side effects as Actos; however, it can also cause lactic acid buildup which can be life-threatening.

When Actos is combined with other diabetic medications like metformin, you have an increased risk of experiencing low blood sugar or hypoglycemic episodes. 

The FDA Adverse Event Reporting System (FAERS) tracks adverse events reported by doctors. As of September 2019, it showed 20,135 reports involving Actos since 1999. Out of these, 16,404 events were flagged as serious and included 2,725 deaths. The FDA notes the medication may not be directly responsible for the complications or deaths, but it may have played a role.

Numerous studies have shown that high doses of the drug increase the risk of bladder cancer. A recent review by the US Food and Drug Administration (FDA) found similar results.

Tell your doctor if you're in an accident, undergo a surgical procedure, or develop a fever, infection, or any other medical condition. These experiences can put extra stress on your body, so your doctor might need to adjust your Actos dose. Don't change your dose without talking to your doctor first.

It's important to keep up with your diet and exercise routine and regularly check your blood sugar levels while taking Actos. Your doctor may test your hemoglobin A1c (HbA1c) to determine if the medication is working.

Actos can cause fluid buildup in the eyes and affect your vision, which may lead to diabetic eye disease. For this reason, your doctor should also check your eyes regularly.

Long-term use of Actos

The long-term safety of Actos is yet to be established. Below are some of the potential complications associated with prolonged Actos use:

  • Heart disease

  • Stroke

  • Liver damage

  • Kidney failure

  • Certain types of cancer

  • Cataracts

  • Pneumonia

  • Gallbladder disease

  • Bone fractures

  • Severe diarrhea and abdominal pain

  • Skin infections

Missed doses

Actos should only be taken once daily. If you miss a dose, take it as soon as possible. Do not double up on your next dose.


Taking an overdose of Actos can be life-threatening. Get medical help immediately if you think someone has overdosed on Actos and is showing any of the following symptoms: 

  • Rapid heartbeat

  • Sweating

  • Confusion

  • Agitation

  • Hallucinations

  • Coma

  • Seizures

What to discuss with your doctor before taking Actos

Your doctor should order a blood test before prescribing Actos to check for liver problems and any other conditions that suggest you shouldn’t take the medication. Be sure to tell your doctor about any conditions you have.

If you have type 1 diabetes or have had diabetic ketoacidosis in the past, you should not take Actos.

Tell your doctor if you have bladder cancer or a history of bladder cancer.

Actos can increase the chance of pregnancy in some women and cause harm to a fetus. The medicine can also pass into breast milk.

You may need to stop taking some medicines, vitamins, or supplements if you're taking Actos. For example, combining Actos with insulin or another antidiabetic medication can increase your risk of having very low blood glucose levels, so your doctor may reduce the dosage of Actos or any other medication you’re taking.

Children under 18 should not take Actos.

When to stop taking Actos

If you develop any of these signs or symptoms, stop taking Actos immediately and call your doctor.

  • Unusual bleeding from any part of your body

  • Sudden weight gain

  • Adverse skin reactions such as redness or itching

  • Dark urine

  • Seizures

  • Fast heartbeat

  • Stomach pain

Actos and pregnancy

Actos can harm an unborn baby. If you get pregnant or you are trying to conceive, tell your doctor immediately. You shouldn’t take Actos if you're breastfeeding.

Clinical trial history

The (FDA) approved Actos in 1999, Actoplus Met in 2005, and Actoplus Met XR in 2009.

A clinical trial³ was carried out to determine if pioglitazone could delay complications from macrovascular disease (a disease that affects the large blood vessels). Researchers aimed to find out if pioglitazone taken with other medications to treat type 2 diabetes could decrease the incidence of macrovascular complications like ischemic heart disease, peripheral vascular disease, and cerebrovascular disease. These complications can cause organ and tissue damage and may ultimately be fatal.

The trial participants were aged between 35 and 75 and had type 2 diabetes and a history of macrovascular disease. Researchers measured how much time passed between treatment starting and a macrovascular event occurring (for example, heart attack, stroke, leg amputation, acute coronary syndrome, cardiac intervention, or leg revascularization).

The incidence rate was found to be 10% lower⁴ after a mean follow-up time of 34.5 months in patients who received pioglitazone compared to those who were given a placebo, indicating that pioglitazone could delay complications from macrovascular disease.

Clinical trial on prediabetes

A randomized, double-blind, placebo-controlled trial⁵ was carried out to determine if Actos could reduce the risk of people converting from prediabetes (or impaired glucose tolerance) to full diabetes.

Compared to placebo, Actos reduced the risk of conversion from prediabetes to diabetes by 72%; however, it was associated with significant weight gain and edema (swelling). 

Actos FAQ

Do I need to undergo lab tests to monitor for side effects of Actos?

Yes, it's certainly possible that you may need lab tests if you're taking Actos. Before you start taking Actos, your doctor may carry out a liver function test to check your liver health.

Does the risk of side effects from Actros depend on the strength I am taking (15mg, 30mg, or 45mg)?

Yes. Some Actos side effects may be dose-dependent, meaning your risk of experiencing them increases alongside your dosage.

Do Actos side effects vary depending on whether I take it alone or with metformin (a diabetes medication)?

Yes. you might experience different side effects if you take Actos with metformin, although they are largely the same. Metformin often causes gastrointestinal problems, including nausea, vomiting, constipa­tion, and diarrhea. If you take Actos with metformin, you may experience these side effects.

Is Actos a dangerous drug?

Actos has been associated with numerous side effects⁶, including an increased risk of bladder tumors. However, these risks are not always present. According to a ten-year study, the risk of developing urinary tract cancer increases with the length and amount of time the drug is taken.

What is the most serious side effect of Actos?

People with underlying heart conditions may be more at risk of heart failure when taking Actos⁷.

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Here at HealthMatch, we’ve done our best to ensure that the information provided in this article is helpful, up to date, and, most importantly, accurate.

However, we can’t replace the one-to-one advice of a qualified medical practitioner or outline all of the possible risks associated with this particular drug and your circumstances.

It is therefore important for you to note that the information contained in this article does not constitute professional medical or healthcare advice, diagnosis or recommendation of treatment and is not intended to, nor should be used to, replace professional medical advice. This article may not always be up to date and is not exhaustive of all of the risks and considerations relevant to this particular drug. In no circumstances should this article be relied upon without independent consideration and confirmation by a qualified medical practitioner.

Your doctor will be able to explain all possible uses, dosages, precautions, interactions with other drugs, and other potential adverse effects, and you should always talk to them about any kind of medication you are taking, thinking about taking or wanting to stop taking.

Curious about clinical trials?

Access the latest treatments and medications. unavailable elsewhere - entirely free of charge. We make it easy to take part.