Pioglitazone with Guar Gum Interaction Details

Brand Names Associated with Pioglitazone

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Dec 02, 2023

Interaction Effect

Increased risk of hypoglycemia

Interaction Summary

Concomitant administration of guar gum and metformin reduced the rate and extent of absorption of metformin in healthy subjects. Guar gum, acting as a gel, delays gastric emptying and subsequent delivery of metformin to its site of absorption . Guar gum has not been reported to interfere with the absorption of newer formulations of glyburide . In one study, the hypoglycemic effect of glyburide was enhanced with concomitant guar gum administration . Guar gum lowered glipizide absorption in healthy subjects, though not statistically significantly . Guar gum and acarbose synergistically reduced blood glucose following a sucrose load in patients with diabetes . Guar gum may also delay absorption of glucose from meals, leading to less postprandial hyperglycemia . It is unknown what effect guar gum has on the absorption of other antidiabetic agents, but may be expected to additively reduce blood glucose. Closely monitor blood glucose levels and signs and symptoms of hypoglycemia when both agents are used together.

Severity

Moderate

Onset

Rapid

Evidence

Probable

How To Manage Interaction

Guar gum may delay absorption of glucose from meals, leading to less postprandial hyperglycemia. Closely monitor blood glucose levels and signs and symptoms of hypoglycemia in patients taking guar gum and antidiabetic agents.

Mechanism Of Interaction

Delayed gastric emptying by guar gum

Literature Reports

A) Guar gum administered with metformin significantly decreased metformin AUC and slightly lowered blood glucose levels for 6 hours in 6 volunteers without diabetes. Volunteers included 5 men and one woman ages 24 to 32 years and within 10% of their ideal body weight. Metformin 1700 mg was prescribed followed by a prescribed meal. Two days later, the same regimen was repeated with the addition of guar gum 10 grams (powder stirred in water) taken together with metformin. Within one hour of concomitant administration, metformin blood levels were reduced by approximately 40% and continued at reduced levels for another 6 hours. Bioavailability was also reduced, as AUC decreased from 1025 +/- 76 milligrams per liter per hour (mg/L/hour) to 621 +/- 57 mg/L/hour (p less than 0.001). Following metformin and guar gum intake, blood glucose levels were slightly lower for the next 6 hours than when metformin was taken alone .

B) The hypoglycemic effect of glyburide was significantly enhanced with concomitant guar gum administration in 10 healthy female volunteers. Glyburide 5 mg was taken with guar gum 5 grams or placebo following an overnight fast. Blood samples were drawn and volunteers then consumed a meal. Blood glucose was significantly reduced when guar gum was coadministered (p less than 0.01 at 0.75 hours and 1.5 hours, p less than 0.001 at 1 hour). Serum insulin and C-peptide were significantly increased at 0.75 hours and 1 hour (p less than 0.001). Serum glyburide concentrations were not measured, and the glyburide used in the study was an older formulation (HB 419) whose absorption is decreased by guar gum. The authors state that absorption of the newer galenic form (HB 420) is not affected by guar gum .

C) Guar gum significantly reduced urinary glucose output in 9 patients with diabetes. Patients supplemented their home diet (n equal to 4) or metabolic ward diet (n equal to 5) with guar gum 25 grams daily for 5 or 7 days. Six patients were treated with insulin (doses ranged from 38 units/day to 84 units/day), while one was controlled with diet alone. In the home diet studies, guar gum was incorporated into bread, canned soup, and fruit juice, and taken at the beginning of meals. During control periods, equal amounts of bread, canned soup, and fruit juice were taken. In metabolic ward studies, guar gum was given in bread, soup, and mashed potatoes. Urinary glucose output decreased by 46% (p less than 0.05) with the home diet and 54% (p less than 0.01) with the metabolic ward diet. Mean urinary glucose output for the home diet was reduced from 26.3 +/- 11.5 grams/24 hours to 14.1 +/- 9.8 grams/24 hours (p less than 0.05). Mean urinary glucose output for the metabolic ward diet was reduced from 29.0 +/- 9.2 grams/24 hours to 13.3 +/- 7.3 grams/24 hours (p less than 0.01). One study was stopped due to recurrent hypoglycemic episodes during the guar gum treatment period. Three patients found it necessary to reduce their insulin dose temporarily after the study, though they were taking their original dose within 2 weeks .

D) Glipizide absorption was not significantly affected by guar gum in 10 healthy volunteers. Glipizide 2.5 mg alone, glipizide 2.5 mg coadministered with guar gum 4.75 grams, or guar gum 4.75 grams 30 minutes after glipizide 2.5 mg were administered, followed by a standard breakfast 30 minutes after glipizide administration. Absorption of glipizide was rapid for all three treatment approaches, perhaps explaining why glipizide is minimally affected by guar gum. Glipizide concentration at 30 minutes was highest when guar gum was coadministered (p less than 0.01). The area under the curve (AUC) for the entire 8 hour period was not significantly different when glipizide was administered alone, with guar gum, or guar gum given 30 minutes following glipizide administration (2330 nanomoles per liter per hour (nmol/L/hour), 2240 nmol/L/hour, and 1950 nmol/L/hour, respectively). Similarly, AUC for insulin and glucose was not significantly altered between the three treatment approaches, though the highest concentrations of insulin and glucose at 30 minutes occurred with glipizide/guar gum simultaneous administration .

E) Guar gum and acarbose synergistically reduced blood sugar following a sucrose tolerance test in a trial of 50 patients with non-insulin dependent diabetes. Patients were randomized to three groups: guar gum 20 grams (n=20), acarbose 100 milligrams (mg) (n=10), or guar gum 10 grams plus acarbose 50 mg. Blood glucose was measured at 0, 30, 60, 90, and 120 minutes after a sucrose load. Blood glucose was significantly lowered at all time points in all groups (p less than 0.001). Guar gum plus acarbose lowered blood glucose more than either drug alone (statistical significance not stated) .

Pioglitazone Overview

• Pioglitazone is used with a diet and exercise program and sometimes with other medications, to treat type 2 diabetes (condition in which the body does not use insulin normally and therefore cannot control the amount of sugar in the blood). Pioglitazone is in a class of medications called thiazolidinediones. It works by increasing the body's sensitivity to insulin, a natural substance that helps control blood sugar levels. Pioglitazone is not used to treat type 1 diabetes (condition in which the body does not produce insulin and, therefore, cannot control the amount of sugar in the blood) or diabetic ketoacidosis (a serious condition that may develop if high blood sugar is not treated).

• Over time, people who have diabetes and high blood sugar can develop serious or life-threatening complications, including heart disease, stroke, kidney problems, nerve damage, and eye problems.Taking medication(s), making lifestyle changes (e.g., diet, exercise, quitting smoking), and regularly checking your blood sugar may help to manage your diabetes and improve your health. This therapy may also decrease your chances of having a heart attack, stroke, or other diabetes-related complications such as kidney failure, nerve damage (numb, cold legs or feet; decreased sexual ability in men and women), eye problems, including changes or loss of vision, or gum disease. Your doctor and other healthcare providers will talk to you about the best way to manage your diabetes.

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.

Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.

Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.

Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.