MEMBRANEBLUE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MEMBRANEBLUE (MEMBRANEBLUE).
Methylene blue (Membraneblue) is a selective inhibitor of guanylyl cyclase, thereby reducing cyclic guanosine monophosphate (cGMP) levels. It also acts as an electron carrier in the reduction of methemoglobin to hemoglobin.
| Metabolism | Reduced by NADPH-dependent methemoglobin reductase to leukomethylene blue; excreted in urine and bile. |
| Excretion | Renal: approximately 60-70% unchanged; biliary/fecal: 20-30% as conjugated metabolites; minor pulmonary excretion. |
| Half-life | Terminal elimination half-life 2.5-3.5 hours in adults; prolonged in hepatic or renal impairment (up to 6-8 hours). |
| Protein binding | Approximately 85-90% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.35-0.45 L/kg, indicating primarily extracellular distribution. |
| Bioavailability | Intravenous: 100% (only route); oral bioavailability negligible (<1%) due to extensive first-pass metabolism. |
| Onset of Action | Intravenous: 1-2 minutes; oral: not applicable (no oral formulation). |
| Duration of Action | Intravenous: 30-45 minutes for clinical effect (cardiac dye visualization); persists up to 1 hour in plasma. |
2 mg/kg intravenously once, administered over 30 minutes; may repeat once if clinically indicated after 30 minutes.
| Dosage form | SOLUTION |
| Renal impairment | No specific dose adjustment recommended; use caution in severe renal impairment (eGFR <30 mL/min/1.73 m²) due to limited data. |
| Liver impairment | No specific dose adjustment recommended; use with caution in severe hepatic impairment (Child-Pugh Class C) due to potential for altered metabolism. |
| Pediatric use | 2 mg/kg intravenously once, not to exceed 100 mg total dose; repeat dosing not typically recommended. |
| Geriatric use | No specific dose adjustment required; monitor for renal function and fluid overload due to age-related physiological changes. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for MEMBRANEBLUE (MEMBRANEBLUE).
| Breastfeeding | Breastfeeding safety not established. M/P ratio unknown. Use caution during lactation due to potential for excretion. |
| Teratogenic Risk | Current evidence indicates no increased risk of major congenital malformations with prenatal exposure. No known fetal risks during any trimester. However, human data are limited. |
| Fetal Monitoring | Routine prenatal monitoring recommended. No specific fetal monitoring required. |
■ FDA Black Box Warning
Serotonin syndrome with concurrent serotonergic drugs (especially SSRIs, SNRIs, MAOIs); discontinue serotonergic agents prior to use; do not use in patients taking serotonergic drugs.
| Serious Effects |
Known hypersensitivity to methylene blue; concurrent use with serotonergic drugs (SSRIs, SNRIs, MAOIs); severe G6PD deficiency.
| Precautions | Risk of serotonin syndrome when used with serotonergic agents; may cause severe hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency; may cause interferences with pulse oximetry readings; monitor methemoglobin levels; may cause fetal harm. |
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| Fertility Effects | No data on fertility impairment. Animal studies show no adverse effects on male or female fertility. |