10 Actos (Pioglitazone) Side Effects: Weight Gain, Swelling, and More

Actos (pioglitazone) is an oral medication used to treat Type 2 diabetes in adults. It's usually prescribed in combination with other medications, a healthy diet, and exercise to manage blood glucose (sugar) levels. Actos is effective for this use, but it has several side effects to be aware of.

Common Actos side effects include headaches, swelling, and weight gain. But more serious issues, such as new or worsening heart failure and bone fractures, have also been associated with the medication. Whether you're considering starting Actos or have been taking it for years, it's a good idea to understand these potential risks.

Actos side effects at a glance

Which, if any, Actos side effects you experience may depend on your dosage and whether you're taking it with other medications. For many people, Actos side effects are mild and can be managed at home. While less common, more serious side effects are also possible.

Common Actos side effects include:

• Upper respiratory tract infections (URTIs), such as the common cold and sinus infections

• Headaches

• Muscle pain

• Sore throat

• Low blood glucose (hypoglycemia)

• Swelling

• Weight gain

Less common but potentially serious Actos side effects include:

• Increased risk of bone fractures

• Eye problems

• Increased risk of bladder cancer

Actos also has a boxed warning (the FDA's strictest medication warning) about the risk of new or worsening heart failure. Below, we'll dive into 10 Actos side effects in more detail and offer tips on how to manage them.

1. Upper respiratory tract infections

It's normal for adults to have two or three colds each year. But during clinical trials, a greater percentage of people taking Actos reported experiencing URTIs compared to those taking a placebo. Examples of URTIs include the common cold and sinus infections. It's not clear if Actos directly increases the risk of URTIs or if this is due to other factors. For example, people with diabetes are already at an increased risk for infections.

There isn't a cure for the common cold. But most people recover within 2 weeks, and the symptoms can usually be managed at home. Besides rest and fluids, over-the-counter (OTC) pain and fever reducers, cough suppressants, and decongestants can be helpful. Your prescriber or pharmacist can suggest options that are safe for you to take.

Sinus infections typically don't require treatment with prescription medications. Remedies that you can try at home include OTC pain medications, placing a warm compress over your forehead and nose, and breathing in steam. But since diabetes can weaken your immune system, it's best to contact your prescriber if you think you might have a sinus infection.

Keep in mind: Many cold and flu medications contain sugar, which may raise your blood glucose levels. Look for sugar-free options or ask your pharmacist for help.

2. Headaches

People taking Actos also report experiencing headaches. Headaches related to Actos may improve as your body adjusts to the medication. But keep in mind that headaches can also be a symptom of high blood glucose (hyperglycemia) or low blood glucose. If you experience a headache, check your blood glucose to make sure it's within your target range.

Most of the time, headaches related to Actos can be managed at home and will go away on their own. But if they're persistent or interfering with your daily activities, talk to your prescriber. They may recommend taking an OTC pain medication, such as acetaminophen (Tylenol), for relief.

3. Muscle pain

Muscle pain is another possible Actos side effect. It's not clear if Actos actually causes muscle pain or if there's another reason for this association. But there has been at least one report of rhabdomyolysis by someone being treated with Actos. Rhabdomyolysis happens when muscle tissue breaks down, releasing harmful substances into the bloodstream.

To manage mild muscle pain at home, there are a few things you can try, including applying a cold or hot compress to the affected muscle(s). There are also many OTC oral and topical pain relievers that may help. But if you have muscle pain that is severe or isn't going away, contact your prescriber. And get immediate medical care if you have severe muscle pain, weakness, and tea-colored urine.

4. Sore throat

Some people taking Actos in clinical trials reported a sore throat, which is usually caused by an infection. A sore throat related to Actos usually goes away on its own, but you can try at-home treatments for symptom relief. A few examples include:

• Using numbing throat spray or lozenges

• Taking oral pain relievers

• Using demeculants (medications that coat the throat)

• Gargling salt water

• Drinking warm fluids

If you have additional symptoms, such as a fever, you should see your primary care provider. They can make sure you don't need additional treatment.

5. Low blood glucose

Low blood glucose, or hypoglycemia, is possible with all diabetes medications. But the risk varies depending on the medication. When taken on its own, Actos carries a low risk of hypoglycemia. But the risk is higher if you take it with diabetes medications like insulin or sulfonylureas. Because of this, your prescriber may adjust your medication dosages if you're combining Actos with other diabetes medications.

If you feel lightheaded, dizzy, or shaky, check your blood glucose, as these could be symptoms of hypoglycemia. If your blood glucose is low (less than 70 mg/dL), follow the instructions you've been given for how to safely bring it back up. If your blood glucose is below 55 mg/dL, this is considered severe and you may need someone to administer glucagon, if it's available, and call 911.

Tell your diabetes care team if you're experiencing hypoglycemic episodes. They may need to adjust your medication regimen.

6. Weight gain

Some diabetes medications can cause weight gain, while others can cause weight loss or not affect body weight at all. Actos has been associated with weight gain. One of the ways this is thought to happen is through increased fat storage. Another way is through fluid retention, which we'll cover in the next section. A 2019 systematic review and meta-analysis found people taking Actos gain about 2 kg (4.4 lbs) on average.

There are ways you can manage possible weight gain from Actos. Following a diabetes-friendly diet and incorporating more movement into your routine are two strategies that can help.

If you're concerned about weight gain, talk to your diabetes care team about lifestyle changes that can help you meet your treatment goals and manage side effects. If needed, they may recommend a different diabetes medication that doesn't affect body weight (or that typically causes weight loss).

7. Swelling

Actos can cause you to hold onto fluid, especially if you're taking a higher dosage and also taking insulin. This can cause swelling (edema) and weight gain. Swelling can be concerning, especially if you have a health condition such as heart failure or kidney problems.

Tell your prescriber if you notice swelling in your arms or legs. They may recommend that you try putting your legs up or wearing compression socks. If needed, they may lower your dosage of Actos, which can help lessen swelling. But if swelling becomes a problem, your prescriber may switch you to a different diabetes medication.

8. Heart failure

As covered above, Actos can cause fluid retention. This can worsen heart failure symptoms, since the extra fluid makes it harder for the heart to pump blood. In fact, pioglitazone has a boxed warning about the risk of new or worsening heart failure.

Because of this risk, Actos isn't recommended if you have symptomatic heart failure. And it should be avoided altogether if you have moderate-to-severe heart failure. There are other diabetes medications, such as sodium-glucose cotransporter-2 (SGLT2) inhibitors, that are recommended for people with heart failure.

After starting treatment with Actos, tell your prescriber if you notice symptoms such as rapid weight gain, swelling, or shortness of breath. They may lower your dosage or have you stop taking Actos as a precaution.

9. Bone fractures

Actos has been linked to an increased risk of bone fractures, especially in older adults and women. Decreased bone mineral density (an indicator of bone strength) has been associated with Actos, which may explain this risk.

Talk to your primary care provider about ways to keep your bones healthy while taking Actos. They may recommend increasing your calcium intake and regularly doing weight-bearing exercises. They may also want to order lab tests to check the strength of your bones.

10. Eye problems

Some people taking Actos have developed macular edema, or swelling in the back of your eye. As mentioned, Actos causes fluid retention and swelling, which may also affect the eyes. One observational study of over 100,000 people found that the highest risk of macular edema was among those taking medications like Actos with insulin.

Macular edema is also a potential complication of diabetes. The condition can lead to permanent vision loss if it isn't treated, so be sure to keep up with your regular eye exams. And tell your prescriber right away if you notice vision changes, such as blurry vision or seeing objects less clearly.