Prescription medication · Biguanide / TZD Combination

metformin/pioglitazone

Also sold as Actoplus Met. Actoplus Met helps lower blood sugar in adults who have type 2 diabetes.

Data updated 2026-05-15

164,328
FDA reports
10
InteractionsSeveral interactions
Rx
Availability

What the data shows

metformin/pioglitazone (Actoplus Met) is a prescription Biguanide / TZD Combination, with 164,328 FDA adverse-event reports on file, with 10 documented drug interactions.

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

metformin/pioglitazone (Actoplus Met) is a prescription Biguanide / TZD Combination. Actoplus Met helps lower blood sugar in adults who have type 2 diabetes.

Actoplus Met is a drug that combines two medicines to help control blood sugar in adults with type 2 diabetes. It should be used with diet and exercise.

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What it does

Actoplus Met helps lower blood sugar in adults who have type 2 diabetes.

Common side effects

Upper respiratory infection, Swelling, Diarrhea

Key warnings

Actoplus Met can cause or worsen heart failure in some people.

The sections below are summarized in plain English from metformin/pioglitazone's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Actoplus Met contains pioglitazone and metformin. Pioglitazone makes your body more sensitive to insulin. Metformin reduces the amount of sugar your liver releases into your blood.

Side Effects (from patient reports)

Based on 164,328 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for metformin/pioglitazone, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS)

Serious Warnings

Actoplus Met can cause or worsen heart failure in some people. Watch for signs like rapid weight gain, shortness of breath, and swelling. This medicine can also cause a rare but serious condition called lactic acidosis. Get medical help right away if you have symptoms like feeling very weak, muscle pain, trouble breathing, or stomach pain.

Known Drug Interactions

moderate dolutegravir

( 7.3 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), may increase the accumulation of metformin. 7.4 Drugs that Reduce Metformin Clearance Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical...

Mechanism: Dolutegravir interferes with how your kidneys remove metformin from your body, causing the drug to stay in your system longer. This can lead to a dangerous buildup of acid in your blood.

moderate ranolazine

( 7.3 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), may increase the accumulation of metformin. 7.4 Drugs that Reduce Metformin Clearance Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical...

Mechanism: Ranolazine blocks the pathways your kidneys use to get rid of metformin, which can cause metformin levels to rise too high. High levels of this drug increase the risk of a life-threatening acid imbalance.

moderate cimetidine

( 7.3 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), may increase the accumulation of metformin. 7.4 Drugs that Reduce Metformin Clearance Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical...

Mechanism: Cimetidine makes it harder for your kidneys to clear metformin out of your blood. This causes the medicine to accumulate in your body, which can lead to a serious side effect called lactic acidosis.

minor metformin

( 7.3 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine), may increase the accumulation of metformin. Therefore, the maximum recommended dosage of ACTOPLUS MET is 15 mg of pioglitazone and 850 mg of metformin HCl once daily if used in combination with gemfibrozil or other strong CYP2C8 inhibitors [see Dosage and Administration (2.3) , Clinical Pharmacology (12.3) ] . Therefore, if an inducer of CYP2C8 is started or stopped during treatment with ACTOPLUS MET, changes in diabetes treatment may be needed based on clinical response without...

Mechanism: Taking two medicines that both contain metformin can cause too much of the drug to build up in your body.

minor topiramate

( 7.6 ) Topiramate may decrease pioglitazone concentrations. 7.3 Carbonic Anhydrase Inhibitors Topiramate or other carbonic anhydrase inhibitors (e.g., zonisamide, acetazolamide or dichlorphenamide) frequently causes a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. 7.8 Topiramate A decrease in the exposure of pioglitazone and its active metabolites were noted with concomitant administration of pioglitazone and topiramate [see Clinical Pharmacology (12.3) ] .

Mechanism: Topiramate can lower the levels of pioglitazone in your body, which might make it work less effectively. It can also cause a change in your blood's acid levels.

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This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

What should I do if I experience swelling in my legs or ankles?
Contact your doctor right away, as this could be a sign of heart failure.
Can I drink alcohol while taking Actoplus Met?
Avoid drinking too much alcohol, as it can increase your risk of lactic acidosis.
Will Actoplus Met cause me to gain weight?
Weight gain is a common side effect of this medicine.
How often will I need blood tests while taking Actoplus Met?
Your doctor will check your liver and kidney function before you start taking Actoplus Met and may monitor them regularly during treatment.
Can Actoplus Met be used for type 1 diabetes?
No, Actoplus Met is only for type 2 diabetes.
What if I take too much Actoplus Met?
Call your doctor or go to the nearest emergency room immediately.
Does Actoplus Met interact with other medications?
Yes, Actoplus Met can interact with other medications. Tell your doctor about all the medicines you take, including prescription and over-the-counter drugs, vitamins, and herbal supplements.
Can Actoplus Met cause low blood sugar?
Actoplus Met can cause low blood sugar, especially if you are also taking insulin or other diabetes medicines. Talk to your doctor about how to prevent and treat low blood sugar.
What are the symptoms of lactic acidosis?
Symptoms include feeling very weak, muscle pain, trouble breathing, stomach pain, feeling cold, and dizziness.
I have heart failure. Can I take Actoplus Met?
You should not take Actoplus Met if you have severe heart failure.
What are the common side effects of metformin/pioglitazone?
The registry lists Upper respiratory infection, Swelling, Diarrhea, Headache, Weight gain among the most-reported FAERS reaction terms for metformin/pioglitazone. The compiled record contains 164,328 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does metformin/pioglitazone interact with other medications?
The registry has 10 documented interaction rows for metformin/pioglitazone. Notable source-record pairings include dolutegravir, ranolazine, cimetidine. These rows are not a complete medication review.
What drug class is metformin/pioglitazone?
metformin/pioglitazone belongs to the Biguanide / TZD Combination drug class. It requires a prescription (Rx). Actoplus Met helps lower blood sugar in adults who have type 2 diabetes.
What pregnancy or breastfeeding source fields are listed for metformin/pioglitazone?
The FDA label for metformin/pioglitazone contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.

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What the FDA Data Shows for metformin/pioglitazone

The FDA label for metformin/pioglitazone (sold under brand names such as Actoplus Met) classifies it as a prescription-only medication in the Biguanide / TZD Combination class. Actoplus Met helps lower blood sugar in adults who have type 2 diabetes. Official labeling lists 5 commonly reported side effects, including Upper respiratory infection, Swelling, Diarrhea.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 164,328 voluntary reports. The database also lists 10 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: March 27, 2025

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Read our methodology - how this data is sourced, computed, and verified.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page