Sil-Norboral

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Sil-Norboral

Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Sil-Norboral

Defining Sil-Norboral: Fixed-Dose Combination and Antihyperglycemic Class

Property Description
Active Ingredients Glibenclamide, Metformin Hydrochloride
Form Tablet (Oral Route)
Pharmacological Class Sulfonylurea + Biguanide (Antihyperglycemic Agent)
Common Use Improving glycemic control in adults with Type 2 Diabetes Mellitus
Origin Synthetic Compounds

Sil-Norboral is an Oral Antihyperglycemic Agent classified as a fixed-dose combination product, specifically developed for the management of Type 2 Diabetes Mellitus (T2DM). The preparation is explicitly indicated as an adjunct to diet and exercise to improve glycemic control in adults. The tablet serves as the standard dosage form for this medicine, designed to be taken via the oral route. Its identity as a fixed-dose combination signifies that the two distinct active ingredients are delivered simultaneously, simplifying the therapeutic strategy for achieving sustained blood sugar regulation.


Core Composition: Glibenclamide, Metformin Hydrochloride, and Differentiation

The efficacy of Sil-Norboral is rooted in the strategic combination of two primary synthetic chemical substances: Glibenclamide (a sulfonylurea derivative) and Metformin Hydrochloride (a biguanide). The two constituent active ingredients operate through complementary actions to provide comprehensive support and are clinically recognized for their role in managing blood sugar in patients who have not achieved target goals with metformin alone. Glibenclamide is an active compound belonging to the sulfonylurea pharmacological class, while Metformin Hydrochloride is a derivative of the biguanide class, a category established for its glucose-lowering properties.


The General Purpose of Dual-Action Antidiabetic Therapy

The primary general purpose of the Sil-Norboral combination is to provide enhanced glycemic control in patients with Type 2 Diabetes Mellitus who need support from more than one therapeutic class. Combination therapy is widely utilized for effectively treating this multifactorial disease by two different mechanisms. This dual-action approach offers a strategically combined way for patients to manage their elevated blood glucose levels, which is the typical use scenario for this fixed-dose oral preparation.

What side effects are possible with Sil-Norboral?

Possible side effects and safety information

The safety profile of the Glibenclamide/Metformin combination is defined by officially documented adverse reactions classified by frequency and affected organ system. Reactions are categorized into several System-Organ Classes, most notably Metabolism and Nutrition Disorders and Gastrointestinal Disorders.

Frequency and Common Reactions

Adverse effects are formally classified by incidence. Very Common reactions typically involve the gastrointestinal system, including diarrhea, nausea, vomiting, abdominal pain, and loss of appetite. These disturbances are often observed at the start of treatment and may diminish over time. Common reactions also include taste disturbance, such as a metallic taste, and mild manifestations of low blood sugar, known as hypoglycemia.

Serious Adverse Reactions and Restrictions

The regulatory profile identifies serious but less frequent risks. Lactic Acidosis is a rare but life-threatening complication associated with the Metformin component, and Severe Hypoglycaemia is a critical risk associated with the Glibenclamide component. These and other effects, such as rare blood disorders (Agranulocytosis) and Hepatitis, are classified as Rare or Very Rare events.

Safety constraints necessitate specific usage restrictions. The medicine is contraindicated in cases of severe Renal Impairment and Severe Hepatic Impairment, as these conditions significantly increase the risk of serious adverse reactions. The label also documents that prolonged use may be associated with the development of Vitamin B12 deficiency. Furthermore, temporary suspension is required before or during medical procedures involving iodinated contrast agents to mitigate risk.

Overdose and Emergency Response

Overdose and when to seek help

Regulatory documentation states that overdose of Sil-Norboral is associated with two distinct, potentially life-threatening conditions derived from its components: severe, prolonged hypoglycemia (Glibenclamide) and Lactic Acidosis (Metformin). Both are classified as medical emergencies.

Documented Manifestations and Severe Outcomes

Overdose leading to severe hypoglycemia may manifest as confusion, excessive sweating, tremors, and can rapidly progress to seizures, coma, and potential irreversible neurological signs. Lactic Acidosis is a serious metabolic complication typically presenting with nonspecific symptoms such as malaise, myalgia (muscle pain), respiratory distress, severe somnolence, and abdominal pain. Laboratory findings will show decreased blood pH and significantly elevated plasma lactate levels.

Required Emergency Actions

The official prescribing information mandates that if symptoms of Lactic Acidosis or severe hypoglycemia occur, the patient must stop taking the medicine and seek immediate medical attention. Prompt hospitalization is required for any suspicion of Lactic Acidosis or for severe hypoglycemia resulting in coma. While no specific antidote is known for Lactic Acidosis, emergency supportive management is described. Prompt hemodialysis is the most effective measure to remove accumulated Metformin, and intravenous glucose is required for severe hypoglycemia. The risk of Lactic Acidosis is increased in patients with significant renal impairment.

Therapeutic Uses of Sil-Norboral

What Sil-Norboral Treats: Main Uses and Benefits

Sil-Norboral is commonly used for managing symptoms associated with a specific chronic condition, where the goal is to address symptoms related to systemic imbalance. Medications in this category are applied across domains where additional symptomatic support is needed to maintain stability.


Managing Episodic Symptom Discomfort

This medication is relevant for easing symptoms related to systemic imbalance, particularly those stemming from symptoms related to heightened physiological activity, which may become intense or disruptive. It helps address symptom clusters that often fluctuate and supports patients during difficult episodes when symptoms create noticeable physiological strain. It involves addressing discomfort in conditions characterized by periods of heightened symptoms and those involving episodic manifestations, and is relevant when supportive symptom management is appropriate.

“It provides support that helps ease the overall symptom burden, contributing to improved comfort during periods of heightened symptoms.”


Supporting Comfort and Stability

Sil-Norboral is applied in clinical settings that involve acute or unstable symptom patterns, and is considered relevant in scenarios where symptoms escalate temporarily. It contributes to improved comfort by providing support that helps ease the overall symptom load, and may help patients cope more steadily with symptom fluctuations associated with the underlying condition. It is commonly used when short-term symptomatic assistance is needed for conditions presenting with acute episodes and managing symptoms that interfere with daily functioning.


Quick Fact: Supports management of Symptoms related to heightened physiological activity.

Regulatory References

  1. NIH overview of Type 2 diabetes medications

Eligibility and Restrictions for Use

Who Can and Cannot Use Sil-Norboral?

Sil-Norboral, a combination of glibenclamide and metformin, is officially restricted to patients diagnosed with Type 2 Diabetes Mellitus. Eligibility is strictly defined by the patient’s health status, primarily due to the risk of lactic acidosis (from metformin) and severe hypoglycemia (from glibenclamide).

Contraindications (Must Not Use)

The medicine is contraindicated and must not be used by patients with:

  • Severe renal impairment (estimated Glomerular Filtration Rate [eGFR] below 30 mL/min/1.73 m^2).
  • Type 1 Diabetes Mellitus or diabetic ketoacidosis.
  • Any form of acute or chronic metabolic acidosis, including lactic acidosis.
  • Known hypersensitivity to glibenclamide, metformin, other sulfonylureas, or sulfonamides.
  • Severe hepatic impairment, alcoholism, or acute alcohol intoxication.
  • Acute conditions that risk tissue hypoxia (e.g., severe heart or respiratory failure, shock, severe infection).

Eligibility-Related Restrictions

  • Renal Function: Initiation of treatment is generally not recommended if eGFR is between 30 and 45 mL/min/1.73 m^2. The medication must be temporarily discontinued before major surgery or certain radiological procedures involving iodinated contrast media.
  • Age: Use in children is not established. Elderly patients (over 65) require frequent assessment of renal function and careful dosage adjustment to mitigate the risk of hypoglycemia and lactic acidosis.

What should I know about interactions with other medicines?

Sil-Norboral, a combination medication containing glyburide (a sulfonylurea) and metformin, can interact significantly with numerous other medications, potentially affecting its efficacy or increasing the risk of adverse effects.

Medications That Increase Hypoglycemia Risk

Since Sil-Norboral lowers blood glucose, combining it with other glucose-lowering agents carries a major risk of hypoglycemia (very low blood sugar). These include insulin, other sulfonylureas, and meglitinides. Additionally, the hypoglycemic effect of Sil-Norboral may be enhanced by certain medications such as:

  • Nonsteroidal Anti-inflammatory Drugs (NSAIDs), including salicylates and phenylbutazone.
  • Some antimicrobial agents, such as miconazole and certain fluoroquinolones.
  • Beta-blockers and ACE inhibitors.

Medications That Reduce Efficacy and Increase Hyperglycemia Risk

Other drugs may decrease Sil-Norboral's effectiveness, leading to hyperglycemia (high blood sugar). These typically include medications that increase blood sugar levels, such as corticosteroids (like prednisone) and thiazide diuretics.

Risk of Lactic Acidosis with Metformin Component

The metformin component of Sil-Norboral increases the risk of lactic acidosis, a rare but serious side effect, when combined with:

  • Alcohol intake should be avoided or severely limited.
  • Iodinated contrast media used in imaging procedures. Sil-Norboral must be temporarily discontinued before and after the procedure.
  • Certain medications that affect kidney function, such as cimetidine and some carbonic anhydrase inhibitors.

Key Drug Interaction Categories

Interaction Type Examples of Interacting Medicines Potential Effect
Increased Hypoglycemia Insulin, Miconazole, NSAIDs, Beta-blockers Dangerously low blood sugar
Increased Hyperglycemia Corticosteroids, Thiazide Diuretics Reduced blood sugar control
Increased Lactic Acidosis Alcohol, Iodinated Contrast Media Serious metabolic complication

Mechanism of Action

Sil-Norboral is a fixed-dose combination containing glibenclamide and metformin, which act via two complementary mechanistic domains to modulate physiological processes related to glucose metabolism.

Pancreatic Beta-Cell Stimulation

Glibenclamide binds to the sulfonylurea receptor 1 (SUR1) on pancreatic beta cells. This interaction closes the ATP-sensitive potassium channels (KATP), causing cell depolarization. The subsequent calcium ion influx triggers the release of pre-formed insulin granules, modifying downstream effectors in the insulin signaling cascade.

Hepatic and Peripheral Action

Metformin's primary mechanism involves the inhibition of the mitochondrial respiratory chain complex I. This action lowers cellular ATP and activates AMP-activated protein kinase (AMPK). AMPK activation initiates two principal effects: first, it suppresses gluconeogenesis in the liver, influencing systemic glucose flux; second, it modulates glucose transport dynamics in muscle and adipose tissue by increasing the translocation of Glucose Transporters (GLUTs) to the cell surface, enhancing cellular glucose uptake.

Dosage and Administration Information

How to Use Sil-Norboral

Sil-Norboral, a fixed-dose combination of Glibenclamide and Metformin Hydrochloride, is approved solely for oral administration as a component of a long-term management plan for Type 2 Diabetes Mellitus. The tablets must be taken with meals (typically breakfast and dinner) to support proper absorption and tolerability.

Dosing and Administration Schedule

Initial treatment for adults typically begins with the lowest available strength, such as 1.25 mg Glibenclamide / 250 mg Metformin Hydrochloride, administered once or twice daily. The total daily dose is intended to be taken in divided portions.

Administration Principle Procedural Instruction
Dose Titration Adjustments must be made gradually, at intervals of not less than two weeks.
Maximum Dose The dose must not exceed a total of 20 mg Glibenclamide and 2000 mg Metformin Hydrochloride daily.

Population-Specific Use Constraints

The official protocol requires dose limitations and strict monitoring for specific patient groups. For older adults, treatment should be initiated with the lowest available dose. Use is contraindicated if a patient’s renal function is severely impaired (eGFR <30 mL/min/1.73 m^2). For those with moderate impairment (30-45 mL/min/1.73 m^2), the initiation of Sil-Norboral is generally not recommended.

If a dose is missed, patients should not double the dose to compensate.

Recent Clinical Evidence

Research evidence / Overview of Studies for Sil-Norboral


Evidence for Use in Type 2 Diabetes Mellitus (T2DM) in Adults

Research on Sil-Norboral, the fixed-dose combination of glibenclamide and metformin, was studied in adults with Type 2 Diabetes Mellitus (T2DM) whose research explored changes in blood glucose levels. The primary body of evidence consists of Randomized Controlled Trials (RCTs). These short-term and intermediate-term trials involved participants whose blood sugar levels were not fully managed by taking a single medicine (either metformin or glibenclamide) alone.

In these trials, research examined changes in specific blood biomarkers used to gauge how the body manages sugar over time. The main outcomes measured were levels of Glycated Hemoglobin ( HbA1c) and Fasting Plasma Glucose (FPG). Research described specific patterns of change in these blood sugar markers when participants received the combination compared to those who received the individual components alone. This evidence contributes to understanding patterns of change in blood glucose biomarkers in adults with T2DM, but do not determine whether an individual will respond similarly.


Comparing Sil-Norboral to Single-Agent Therapy

The trials studies explored the difference between taking the combination pill and taking only one of the active ingredients, or a placebo (inactive pill). This comparative research helps contextualize how the two-drug fixed combination was observed in trials compared to its individual component drugs. Further research monitored groups who were previously taking metformin alone and whose study protocol assigned them to receive either continued metformin or the fixed-dose combination. While the primary efficacy studies focused on comparing the FDC to its components, comparative evidence is lacking for some of the newer, more recently developed combination therapies now available for T2DM.


Long-Term Data and Durability of Study Findings

The clinical evidence supporting Sil-Norboral primarily relates to short-term and intermediate-term follow-up durations, typically ranging from a few weeks up to about six months. This means the research provides insight into short-term changes in blood sugar markers. For questions about long-term health patterns, such as the outcomes related to cardiovascular events over many years, the specific long-term effects of the fixed-dose combination are not fully established by dedicated trials. Data for long-term observation are often derived from the established evidence related to the individual component drugs.


Evidence in Different Adult Subgroups

The clinical research primarily included adults with T2DM, particularly those with a history of inadequate glycemic management on monotherapy. Research describes the specific characteristics of the patients studied, including their age range. Data for certain groups remain insufficient directly from the FDC trials. For instance, limited information is available to characterize the effects of Sil-Norboral in older adults with complex health needs or those with varying degrees of kidney function, and data for certain groups remain insufficient. The results apply only to the populations studied and cannot be generalized across all patients with T2DM.


Key Limitations and Areas of Ongoing Research

Regulators have noted several aspects where research remains uncertain or evidence is limited. One key limitation is that as a fixed-dose combination, the medicine delivers the two active ingredients in a set ratio. This means sample sizes were modest in the primary FDC trials for specific outcomes, and findings describing group patterns highlight what is known—and what is still uncertain. Furthermore, evidence quality varies across studies when the combination is compared to other classes of diabetes medication, and subgroup findings are uncertain in specific populations not included in the main trials. Research is ongoing to better contextualize how this combination fits within the broader treatment landscape.

Key Studies & References CONSENSUS STATEMENT BY THE AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY ON THE COMPREHENSIVE TYPE 2 DIABETES MANAGEMENT ALGORITHM - 2020

Frequently Asked Questions (FAQ)

Common questions about Sil-Norboral (FAQ)


Q: How does the action of Sil-Norboral differ from older treatments for the same condition?

A: Clinical trials observed that the fixed-dose combination (FDC) therapy, Sil-Norboral, was associated with greater reduction in the long-term blood sugar marker, HbA1c, and fasting plasma glucose compared to using the two individual components alone. This combination was also associated with the ability to utilize lower individual component dosages compared to monotherapy.


Q: Are there any specific dietary restrictions to consider while taking Sil-Norboral?

A: The regulatory guidance highlights the importance of adhering to a special meal plan and exercise regimen as directed by a healthcare professional. Regulatory guidance stresses that consumption of alcohol is associated with an increased risk of serious complications like lactic acidosis and severe hypoglycemia, and consumption should be discussed with a healthcare provider.


Q: Does Sil-Norboral require any routine monitoring, such as blood tests?

A: Yes, regulatory documents indicate that regular monitoring is necessary, including scheduled visits with a doctor. This typically involves blood tests, such as checking Hemoglobin A1c levels, to assess the medicine’s effectiveness and overall safety. Monitoring of renal function is also specifically required.


Q: What is the typical timeframe within which a person might switch off Sil-Norboral if it is not effective?

A: Clinical trial data on the medicine’s components suggest that changes in fasting plasma glucose may be seen within eight weeks of treatment, with changes in long-term control ( HbA1c) often observed by twelve weeks. Therapeutic decisions, such as modification or switching, are based on individual clinical assessment.


Q: What is the rate of treatment discontinuation reported in the clinical trials for Sil-Norboral?

A: Studies examining the use of the fixed-dose combination show that discontinuation rates due to adverse effects in one trial were reported to be low, specifically between 0% and 2.8%. The adherence rate for diabetes medications may vary across different patient populations.


Q: How can a person tell the difference between a minor and a serious reaction to Sil-Norboral?

A: Regulatory documents classify reactions by frequency and severity. Very common reactions, such as diarrhea, nausea, and abdominal pain, are typically minor and may diminish over time. Serious but rare reactions include Lactic Acidosis and Severe Hypoglycemia, which are documented as events for which individuals should seek immediate medical assistance.


Q: Is it necessary to inform a dentist or eye doctor about taking Sil-Norboral?

A: Official prescribing information emphasizes that all members of a person's healthcare team, including dentists and eye doctors, should be informed that the person is taking this medicine. This is particularly relevant because temporary suspension of the medication may be necessary before certain medical procedures, such as those involving iodinated contrast agents.


Q: How quickly should a person typically notice the effects of Sil-Norboral?

A: Clinical trial results show that effects on fasting plasma glucose levels typically begin with rapid decreases reported by the end of the first week of treatment, and blood glucose levels continue to decline over the subsequent weeks.


Q: What is the expected duration of action of a single dose of Sil-Norboral?

A: The duration of action relates to how long the medicine stays in the body. According to the regulatory pharmacokinetics section, the plasma half-life (the time it takes for half the dose to leave the plasma) of the Metformin component is approximately 6.2 hours. The half-life of the Glyburide component is also detailed in the official prescribing information.


Q: Is there a known interaction between Sil-Norboral and common herbal supplements like St. John's Wort?

A: Regulatory information cautions that herbal supplements and other nonprescription products, such as St. John’s Wort, may interact negatively with oral hypoglycemics. Official information advises that the use of such products should be reviewed by a healthcare provider prior to initiation.


Q: Does Sil-Norboral have any impact on a person's sleep quality?

A: Official safety information lists unusual sleepiness as a rare side effect that has been reported in some individuals taking the medicine.


Q: What is the official safety classification of Sil-Norboral for individuals who are pregnant?

A: The US FDA has designated the pregnancy category for this combination as Not Assigned. However, regulatory advice suggests its use is not recommended unless clearly needed; insulin is typically the preferred agent for blood glucose control during pregnancy.


Q: Does Sil-Norboral interact with common over-the-counter cold and flu medications?

A: The patient information leaflet states that nonprescription medications for colds, cough, hay fever, or sinus problems should be reviewed by a healthcare provider. This is because these products may interfere with the medicine's effectiveness or increase the risk of side effects.


Q: Is it true that taking Sil-Norboral can cause changes in weight?

A: Studies and official information indicate that treatment with the combination can be associated with a modest increase in mean bodyweight, which has been reported as approximately 1 kg in some clinical trials. Individual weight changes may vary.


Q: Does Sil-Norboral contain any common allergens like gluten or lactose?

A: The inactive ingredients (known as excipients), which include potential common allergens like lactose or starch, are listed in the Description section of the official prescribing information. This list helps identify any components to which a person may be sensitive.


Q: Can exposure to sunlight or UV light be a concern while taking Sil-Norboral?

A: Photosensitivity, which is an abnormal skin reaction to light exposure, has been noted as a potential but rare adverse reaction. This is associated with both the Glibenclamide and Metformin components of the medicine.


Q: What is the purpose of the inactive ingredients included in the Sil-Norboral tablet?

A: The inactive ingredients, or excipients, are essential components added to the active ingredients to form the stable tablet dosage form. According to the official description, these ingredients serve purposes such as binding the components, filling the tablet, and adding coloring.


Q: Does the official evidence indicate a difference in effectiveness between doses?

A: Clinical data for the individual Metformin component shows a dose-response relationship, where a higher daily dose (2,000 mg) provided a greater reduction in the long-term blood sugar marker ( HbA1c) compared to a lower dose (1,500 mg). This suggests that dose is a factor in effectiveness.

How should Sil-Norboral be stored and disposed of?

How to Store and Dispose of Sil-Norboral?

This medicine must be stored according to specific regulatory requirements to maintain its stability and effectiveness. The product should be stored below 30 C. To protect the tablets from environmental factors, it is mandatory to keep the medicine in the original package, including the blister, and ensure the outer carton remains intact to shield it from light and moisture.

Always keep this medicine out of the sight and reach of children.

Do not use Sil-Norboral after the expiry date indicated on the carton and blister. For disposal, unused or expired medicine must not be thrown away via wastewater or household waste. Consult a pharmacist for instructions on how to properly dispose of the medicine in accordance with national and local environmental requirements.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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