Lumeblue: Uses, Dosage & Side Effects

What Is Lumeblue and What Is It Used For?

Lumeblue contains the active substance methylthioninium chloride, more commonly known as methylene blue. Methylene blue is a synthetic phenothiazine dye that has been used in medicine for over a century in various applications, including the treatment of methemoglobinemia, as an antiseptic, and as a biological stain. In the context of Lumeblue, methylthioninium chloride is formulated as a prolonged-release tablet specifically designed to deliver the dye to the colon for the purpose of chromoendoscopy — a technique that uses dyes to enhance the visualization of the mucosal surface during endoscopic examination.

Chromoendoscopy has been recognized for decades as a valuable technique for improving the detection of colorectal neoplasia during colonoscopy. Traditional spray chromoendoscopy involves the endoscopist manually spraying dye solutions (such as indigo carmine or methylene blue) through a catheter during the procedure. While effective, this method is time-consuming, requires additional equipment, adds procedural complexity, and is often not uniformly applied throughout the entire colon. Lumeblue was developed to overcome these limitations by providing a simple oral tablet that achieves whole-colon staining without any additional equipment or time during the procedure itself.

After oral administration, the prolonged-release formulation ensures that methylthioninium chloride is released gradually in the small intestine. The dye is then absorbed into the bloodstream, metabolized, and subsequently excreted via the bile ducts and directly through the intestinal wall into the colon. This process results in a uniform blue staining of the colonic mucosa. Normal, healthy mucosal cells actively absorb the methylene blue dye, appearing dark blue under white-light endoscopy. In contrast, abnormal tissue — such as adenomatous polyps, sessile serrated lesions, and dysplastic areas — either does not absorb the dye or absorbs it to a lesser degree, creating a visible contrast that makes these lesions easier to identify. This differential staining pattern is particularly valuable for detecting flat or subtle lesions that might be missed during standard white-light colonoscopy.

The clinical development of Lumeblue was primarily supported by two pivotal clinical trials that demonstrated its efficacy in improving adenoma detection during colonoscopy:

• DETECTION Trial: This was a randomized, double-blind, placebo-controlled, multicenter phase III trial that enrolled 1,249 patients undergoing screening or surveillance colonoscopy. Patients received either Lumeblue (200 mg) or placebo approximately 3–5 hours before their scheduled colonoscopy. The primary endpoint was the proportion of patients with at least one histologically confirmed adenoma detected. The study demonstrated that patients in the Lumeblue group had a significantly higher adenoma detection rate (56.29%) compared to the placebo group (47.81%), representing an absolute increase of approximately 8.5 percentage points. The mean number of adenomas detected per patient was also significantly higher in the Lumeblue group.
• SPIRIT Trial: This was an open-label, single-arm study designed to evaluate the timing of optimal mucosal staining and to confirm the safety profile of Lumeblue. The study found that adequate mucosal staining was achieved in the majority of patients within 3–5 hours after oral administration, confirming the practical dosing window for the medication.

Colorectal cancer is the third most commonly diagnosed cancer worldwide and the second leading cause of cancer-related death, according to the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC). Screening colonoscopy is one of the most effective strategies for preventing colorectal cancer because it allows for the detection and removal of precancerous adenomatous polyps before they progress to invasive cancer. However, the effectiveness of colonoscopy depends heavily on the adenoma detection rate (ADR) — the proportion of screening colonoscopies in which at least one adenoma is identified. Studies have shown that for every 1% increase in ADR, there is an associated 3% decrease in the risk of interval colorectal cancer (cancer diagnosed between screening colonoscopies). Therefore, technologies and techniques that improve ADR have the potential to significantly reduce colorectal cancer incidence and mortality.

Lumeblue was first approved by the European Medicines Agency (EMA) in November 2020 for use in adults undergoing colonoscopy as part of colorectal cancer screening, surveillance, or diagnostic programs. It represents a novel approach to improving colonoscopy quality by making whole-colon chromoendoscopy accessible through a simple oral tablet, without requiring specialized endoscopic equipment or additional procedural time. The European Society of Gastrointestinal Endoscopy (ESGE) has recognized chromoendoscopy as a technique that can improve polyp detection, and Lumeblue provides a practical means of delivering this benefit in routine clinical practice.

What Should You Know Before Taking Lumeblue?

Contraindications

Lumeblue must not be used in patients with known glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is the most common enzyme deficiency worldwide, affecting approximately 400 million people, with the highest prevalence in populations of African, Mediterranean, Middle Eastern, and Southeast Asian descent. In patients with G6PD deficiency, methylthioninium chloride can trigger severe hemolytic anemia — a potentially life-threatening condition in which red blood cells are destroyed faster than the body can replace them. Symptoms of hemolytic anemia include sudden onset of fatigue, pallor, jaundice (yellowing of the skin and eyes), dark-colored urine, rapid heart rate, and shortness of breath. If G6PD status is unknown, it should ideally be determined before prescribing Lumeblue, particularly in patients from high-risk populations.

Lumeblue is also contraindicated in patients with known hypersensitivity to methylthioninium chloride, any other thiazine dye, or any of the excipients contained in the formulation. Allergic reactions to methylene blue are uncommon but have been reported, including skin rashes, urticaria, and in rare cases, anaphylaxis.

Warnings and Precautions

Methylthioninium chloride has been shown to be a potent reversible inhibitor of monoamine oxidase A (MAO-A). This enzyme is responsible for the breakdown of serotonin (5-hydroxytryptamine, 5-HT) in the body. When MAO-A is inhibited, serotonin levels can rise dangerously, particularly if the patient is also taking medications that increase serotonin levels through other mechanisms. This combination can precipitate serotonin syndrome, a potentially life-threatening condition characterized by mental status changes (agitation, confusion, delirium), autonomic instability (fever, tachycardia, blood pressure fluctuations, diaphoresis), and neuromuscular abnormalities (tremor, clonus, hyperreflexia, rigidity). Severe cases can progress to seizures, rhabdomyolysis, disseminated intravascular coagulation, and death.

Before taking Lumeblue, discuss the following with your healthcare provider:

• All medications you are currently taking, including prescription drugs, over-the-counter medications, herbal supplements (particularly St. John's Wort, which has serotonergic properties), and recreational substances. A comprehensive medication review is essential to identify any potential interactions, especially with serotonergic drugs.
• Renal impairment: Methylthioninium chloride is partially excreted by the kidneys. In patients with moderate to severe renal impairment (estimated glomerular filtration rate below 60 mL/min), the dye may accumulate, potentially increasing the risk of adverse effects. Dose adjustments may be considered, and these patients should be monitored more closely.
• Hepatic impairment: Methylthioninium chloride undergoes hepatic metabolism. Patients with significant liver disease may have altered drug metabolism. Clinical data in patients with severe hepatic impairment are limited, and caution is advised.
• Pulse oximetry interference: Methylthioninium chloride can cause falsely low pulse oximetry readings because the dye absorbs light at wavelengths similar to those used by pulse oximeters (660 nm and 940 nm). Healthcare professionals performing the colonoscopy should be aware of this potential artifact and should not rely solely on pulse oximetry for monitoring oxygenation during and after the procedure.
• Photosensitivity: Methylene blue can cause photosensitivity reactions. Patients should be advised to avoid excessive sun exposure and to use appropriate sun protection for several days after taking Lumeblue.

Pregnancy and Breastfeeding

Lumeblue should not be used during pregnancy unless clearly necessary and the potential benefit justifies the potential risk to the fetus. There are no adequate and well-controlled studies of methylthioninium chloride in pregnant women. Animal reproductive toxicity studies have shown adverse effects at doses significantly higher than the human therapeutic dose, including potential teratogenic effects. Methylthioninium chloride crosses the placental barrier. Women of childbearing potential should confirm they are not pregnant before undergoing the procedure, and scheduling of colonoscopy with Lumeblue should take pregnancy status into account.

It is not known whether methylthioninium chloride or its metabolites are excreted in human breast milk. Given the potential for adverse reactions in breastfed infants, a decision should be made whether to discontinue breastfeeding or to avoid using Lumeblue, taking into account the importance of the diagnostic procedure for the mother. If Lumeblue is used, breastfeeding should be avoided for at least 8 days after administration to allow for complete elimination of the drug.

Children and Adolescents

Lumeblue is not indicated for use in children or adolescents under 18 years of age. Colorectal cancer screening colonoscopy is primarily performed in adults, and the safety and efficacy of Lumeblue have not been established in the pediatric population. There are no relevant clinical data to support its use in this age group.

Driving and Operating Machinery

Lumeblue itself is not expected to significantly impair the ability to drive or operate machinery. However, patients should be aware that colonoscopy typically involves sedation or anesthesia, which will affect their ability to drive and operate machinery for the remainder of the day following the procedure. Patients should follow the standard post-colonoscopy guidelines regarding driving and should arrange for someone to accompany them home after the procedure.

How Does Lumeblue Interact with Other Drugs?

The most important drug interaction concern with Lumeblue relates to its activity as a potent reversible inhibitor of monoamine oxidase A (MAO-A). This property means that methylthioninium chloride can significantly increase serotonin levels in the brain when combined with other serotonergic drugs, potentially leading to serotonin syndrome. This interaction has been well-documented in the medical literature, initially identified when intravenous methylene blue was used as a surgical dye and patients on serotonergic antidepressants developed serotonin syndrome. Although the oral dose of methylthioninium chloride in Lumeblue (200 mg) results in lower systemic exposure compared to intravenous administration, the risk of serotonin syndrome remains clinically relevant and the combination is contraindicated.

The U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have both issued warnings about the risk of serotonin syndrome when methylene blue is used in patients taking serotonergic medications. The following table summarizes the key drug interactions with Lumeblue:

Washout Periods for Serotonergic Medications

If a patient is taking a serotonergic medication and requires a colonoscopy with Lumeblue, the serotonergic drug should be discontinued for an appropriate period before the procedure. The required washout period depends on the specific medication's half-life. For most SSRIs and SNRIs, a washout period of at least 2 weeks is generally recommended. For fluoxetine, which has a particularly long half-life (including its active metabolite norfluoxetine), a washout period of at least 5 weeks may be necessary. For MAOIs, a washout period of at least 2 weeks after the last dose is typically required. The decision to temporarily discontinue antidepressant therapy must be made by the prescribing physician, weighing the benefits of enhanced colonoscopy against the risks of interrupting psychiatric medication, including the potential for withdrawal symptoms and relapse of the underlying psychiatric condition.

Other Interactions

Methylthioninium chloride may interact with medications that are metabolized by cytochrome P450 enzymes, as in vitro studies have shown that methylene blue can inhibit several CYP isoenzymes (including CYP1A2, CYP2B6, CYP2C9, and CYP2D6) at high concentrations. However, at the clinical dose of 200 mg administered orally with the prolonged-release formulation, the systemic concentrations of methylthioninium chloride are generally low, and clinically significant CYP-mediated interactions are considered unlikely. Nevertheless, patients taking medications with a narrow therapeutic index that are metabolized by these enzymes should be monitored.

Lumeblue should not be taken concomitantly with other methylene blue–containing products, as this could result in excessive dosing. Additionally, the concomitant use of drugs that lower the seizure threshold should be approached with caution, as high doses of methylene blue have been associated with neurotoxic effects in preclinical studies.

What Is the Correct Dosage of Lumeblue?

Adults

The recommended dose of Lumeblue for adults is 200 mg, administered as eight prolonged-release tablets of 25 mg each. The tablets should be taken by mouth with water on the morning of the colonoscopy. The timing of administration is critical: the tablets should be taken approximately 3 to 5 hours before the scheduled start of the colonoscopy to ensure that adequate mucosal staining has been achieved by the time the endoscopist examines the colon.

Lumeblue should be taken during the clear fluid phase of the bowel preparation regimen. Bowel preparation for colonoscopy typically involves a split-dose polyethylene glycol (PEG)-based or sodium picosulfate–based laxative solution. The standard bowel preparation protocol should be followed as directed by the healthcare provider. Lumeblue tablets should be taken after the first dose of bowel preparation, during the clear fluid intake period, and before the second (morning) dose of bowel preparation if applicable.

The tablets must be swallowed whole and should not be crushed, chewed, or broken. The prolonged-release formulation is specifically designed to release methylthioninium chloride in the small intestine. Damaging the tablet coating would result in premature release of the dye in the stomach, potentially causing inadequate colonic staining, altered pharmacokinetics, and increased risk of gastrointestinal adverse effects.

Elderly Patients

No specific dose adjustment is required for elderly patients. In the pivotal DETECTION trial, a substantial proportion of enrolled patients were over 65 years of age, and the safety and efficacy profile was consistent across age groups. However, elderly patients may have a higher prevalence of renal and hepatic impairment, which should be taken into account. Additionally, elderly patients may be more susceptible to the adverse effects of methylene blue, particularly dizziness, and appropriate precautions should be taken during and after the colonoscopy procedure.

Missed Dose

Lumeblue is administered as a single dose before a specific medical procedure (colonoscopy). If a patient forgets to take the tablets or takes them outside the recommended time window (3–5 hours before the procedure), the colonoscopy should be rescheduled or performed as a standard white-light colonoscopy without the benefit of chromoendoscopy. The patient should not take a double dose to compensate for a missed dose, and should not take additional tablets if they vomit shortly after ingestion without consulting their healthcare provider.

Overdose

In the event of an overdose, symptoms may include nausea, vomiting, abdominal pain, dizziness, headache, confusion, increased sweating, and chest pain. At very high doses, methylthioninium chloride can cause methemoglobinemia (paradoxically, at low doses it is used to treat this condition), hemolytic anemia (especially in patients with G6PD deficiency), and serotonin-like toxicity. Treatment of overdose is supportive and symptomatic. There is no specific antidote for methylthioninium chloride overdose. In severe cases, exchange transfusion may be considered, particularly if significant hemolysis occurs. Patients who have ingested an overdose should seek immediate medical attention and inform healthcare providers of the ingestion.

What Are the Side Effects of Lumeblue?

Like all medicines, Lumeblue can cause side effects, although not everybody gets them. The side effect profile of Lumeblue is primarily related to the pharmacological properties of methylthioninium chloride as a dye and its known biological activities. The most distinctive and expected effect is the blue-green discoloration of urine (chromuria) and feces, which occurs in virtually all patients and should not be a cause for concern. This discoloration typically resolves within 2–4 days after taking the tablets as the dye is eliminated from the body.

In clinical trials, Lumeblue was generally well tolerated. The following side effects have been reported, organized by frequency category according to the MedDRA convention used by the European Medicines Agency:

The blue-green discoloration of urine and feces is an expected pharmacological effect, not a harmful adverse reaction. Patients should be clearly informed about this before taking Lumeblue so that they are not alarmed. The discoloration typically lasts 2–4 days after administration. In some patients, mild blue-green discoloration of the skin may also occur, particularly on the palms and soles, but this is transient and resolves spontaneously.

Gastrointestinal side effects (abdominal pain, nausea, vomiting) are often difficult to distinguish from effects of the bowel preparation itself, which commonly causes similar symptoms. In the DETECTION trial, the overall incidence of adverse events was comparable between the Lumeblue and placebo groups, with bowel preparation–related gastrointestinal symptoms being the most frequently reported events in both groups.

If you experience any side effects not listed above, or if any side effects become serious, please contact your healthcare provider or report them through your country's national pharmacovigilance reporting system. Reporting suspected adverse reactions helps to continuously monitor the benefit-risk balance of medications after their authorization.

How Should You Store Lumeblue?

Proper storage of Lumeblue is important to maintain the quality and efficacy of the medication. The prolonged-release coating of the tablets is sensitive to environmental conditions, and improper storage could compromise the drug's release characteristics, potentially affecting both the staining quality during colonoscopy and the safety profile.

The following storage conditions should be observed:

• Temperature: Store below 25°C (77°F). Do not refrigerate or freeze the tablets.
• Light protection: Store in the original blister packaging to protect from light. Methylthioninium chloride is a photosensitive compound, and exposure to light can cause degradation of the active substance.
• Moisture protection: Keep the tablets in the original packaging until ready to use. Do not remove tablets from the blister pack in advance.
• Child safety: Keep this medicine out of the sight and reach of children. The blue color of the tablets may be attractive to children, and accidental ingestion could be harmful.
• Expiry date: Do not use Lumeblue after the expiry date stated on the blister and carton. The expiry date refers to the last day of that month.

Do not dispose of medications in wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer needed. These measures help to protect the environment. Methylthioninium chloride is a dye that can stain surfaces, clothing, and skin. Handle the tablets carefully and wash hands after handling if any blue discoloration occurs on the skin.

What Does Lumeblue Contain?

Each Lumeblue 25 mg prolonged-release tablet contains the following components:

• Active substance: Methylthioninium chloride 25 mg. Methylthioninium chloride (INN) is the international nonproprietary name for the compound also known as methylene blue, a synthetic cationic thiazine dye with the chemical formula C₁₆H₁₈ClN₃S and a molecular weight of 319.85 g/mol.

The excipients (inactive ingredients) in Lumeblue include substances that form the prolonged-release matrix and protective coatings:

• Tablet core: Sodium carboxymethylcellulose, microcrystalline cellulose, stearic acid, magnesium stearate
• Inner coating (gastro-resistant): Methacrylic acid-methyl methacrylate copolymer (1:1), methacrylic acid-methyl methacrylate copolymer (1:2), talc, titanium dioxide (E171), triethyl citrate
• Outer coating: Methacrylic acid-ethyl acrylate copolymer (1:1), talc, titanium dioxide (E171), triethyl citrate, iron oxide yellow (E172)

The tablets use MMX (Multi-Matrix System) technology, a proprietary drug delivery platform developed by Cosmo Pharmaceuticals. The MMX system is designed to deliver active substances throughout the colon by using a combination of hydrophilic and lipophilic matrices enclosed within a pH-dependent coating. The gastro-resistant inner coating prevents the tablet from releasing its contents in the acidic environment of the stomach. As the tablet passes through the small intestine and encounters the progressively higher pH of the ileum and colon, the coating dissolves, and the methylthioninium chloride is gradually released. This controlled release mechanism ensures that the dye reaches and stains the colonic mucosa uniformly, providing consistent chromoendoscopy during the subsequent colonoscopy procedure.

The tablet is round, dark blue in color, and marked with "CB" on one side. The blue color is inherent to the methylthioninium chloride active substance. Lumeblue is available in blister packs containing 8 tablets (one complete dose for a single colonoscopy procedure). Each carton contains one blister pack.

If you have known allergies or intolerances to any of the listed excipients, inform your healthcare provider before taking Lumeblue. Notably, the formulation contains sodium; however, the sodium content is less than 1 mmol (23 mg) per dose, and the product is therefore considered essentially sodium-free.