From the Guidelines
Methylene Blue should only be taken orally under a doctor's supervision, with a typical dose ranging from 100-300 mg per day, as prescribed for severe cases of congenital methemoglobinemia. When considering the effects of taking Methylene Blue orally, it is crucial to prioritize its use for specific medical conditions, such as methemoglobinemia, and to be aware of potential side effects and interactions. According to the American Journal of Hematology study from 2021 1, oral Methylene Blue (MB) 100–300 mg per day is administered with dose adjustment according to MetHb levels, highlighting the importance of medical supervision.
Key Considerations
- The dose of Methylene Blue can be adjusted based on MetHb levels, as noted in the study 1.
- Certain subgroups of unstable hemoglobins, such as Hb Cheverly and Hb Evans, may respond to Methylene Blue treatment, but this is not typical for all cases of methemoglobinemia.
- Common side effects of Methylene Blue include nausea, vomiting, stomach pain, headache, dizziness, and blue discoloration of skin, although these are not explicitly mentioned in the provided study, they are relevant to consider in real-life clinical practice.
Important Interactions and Precautions
- Methylene Blue should not be taken by people using certain antidepressants, such as SSRIs and MAOIs, due to the risk of serotonin syndrome, a potentially life-threatening condition, although this specific interaction is not mentioned in the study 1, it is a critical consideration in clinical practice.
- Patients should be aware that Methylene Blue can turn urine and sometimes stool blue-green, which is harmless but can be alarming if unexpected.
Clinical Use and Monitoring
- Methylene Blue acts as a reducing agent in the body, helping convert methemoglobin back to normal hemoglobin in blood disorders, and has antimicrobial properties for infections.
- It is essential to follow a doctor's instructions precisely regarding timing and dosage, and to take Methylene Blue with plenty of water to minimize potential side effects.
From the Research
Effects of Methylene Blue
The effects of taking Methylene Blue (methylthioninium chloride) orally are not directly addressed in the provided studies, as they primarily focus on its intravenous administration. However, some studies mention its potential effects and interactions:
- Methylene Blue is generally considered safe when used intravenously to treat methemoglobinemia, but it can cause dose-related hemolytic effects 2.
- The drug can interact with other medications, such as serotonergic medications, and lead to serotonin excess syndrome 3.
- Methylene Blue has been used to treat various conditions, including methemoglobinemia, vasoplegic syndrome, and neuropsychiatric disorders, with reported benefits and risks 4, 5, 6.
Potential Risks and Interactions
Some potential risks and interactions associated with Methylene Blue include:
- Hemolysis, methemoglobinemia, nausea, vomiting, chest pain, dyspnea, and hypertension 5.
- Serotoninergic toxicity, which can manifest as neuromuscular hyperactivity 5.
- Interactions with selective serotonin reuptake inhibitors, which can lead to serotonin syndrome 3.
- Potential risks for patients with G-6-PD deficiency or those exposed to aniline dyes and dapsone 2.
Oral Administration
There is limited information available on the effects of taking Methylene Blue orally. However, one study mentions its use in the treatment of neuropsychiatric disorders, including bipolar disorder, with reported antidepressant and anxiolytic effects 6. Nevertheless, caution is advised due to its potential interactions and side effects.