Effect of Methylene Blue on Blood Pressure in Rats

AimsTo summarise the tolerability profile following an infusion of methylene blue (MB), including subjective effects on mood and energy levels and haemodynamic changes, in patients with Bipolar Affective Disorder (BPAD).BackgroundBPAD is associated with mitochondrial dysfunction and impaired cellular energy production. MB is proposed to enhance mitochondria function via rerouting electrons and intracellular reduction of oxidative stress, and is therefore a candidate compound for use as a probe to reveal alterations in brain oxygen metabolism in vivo in patients with BPAD. Although there are reports of MB used as treatment for BPAD, the tolerability and subjective effects of a single IV dose in this population has not yet been defined.MethodUsing a single-blind, randomised, within-subject design, 7 patients with BPAD on stable pharmacological treatment and 6 healthy controls (HCs) received an infusion of 0.5mg/kg MB and a placebo glucose solution one week apart. Visual Analogue Scales (VAS) assessing ‘Mood’ and ‘Energy’ levels were completed by 11 participants, and blood pressure (BP), heart rate (HR) and any subsequent side effects were recorded before and after infusions.ResultA significant, albeit very small, effect of MB on ‘Mood’ levels relative to placebo was demonstrated, independent of groups (change relative to baseline: 5.5% ± 11 increase (placebo) vs -1.6 % ± 9.5 reduction (MB); p = 0.027). Although there was no effect of MB on energy levels in either group, there appeared to be a trend for a general group difference in ‘Energy’ levels across all trials, with lower ratings in BPAD patients (p = 0.058).There was a trend for significantly lower post-infusion HR relative to pre-infusion (-6.4 ± 8.8 bpm, p = 0.07. Diastolic BP was higher (3.0 ± 7.8mmHg, p = 0.039). These effects were independent of groups and drug. The most common side effect with MB was mild/moderate pain at infusion site (n = 10/13), resolving within median 32.5 minutes (IQR 6-102), and discoloured urine in 7/13 subjects lasting median 44.5 hours (IQR 36-59). No difference in frequency of side effects reported between groups.ConclusionAlthough limited by small sample size, this tolerability analysis demonstrates a acceptable profile of effects of MB on subjective ratings and blood pressure, in both BPAD and HCs. Common side effects of discoloured urine and pain at infusion site are in line with previous reports in the literature. We observed a small effect of MB on mood ratings which could be related to the discomfort experienced during infusion.

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Effect of Methylene Blue on Blood Pressure in Rats

Pharmacology ◽

10.1159/000139047 ◽

1993 ◽

Vol 46 (4) ◽

pp. 206-210 ◽

Cited By ~ 3

Author(s):

Side Oktay ◽

Filiz Onat ◽

Funda Karahan ◽

Inci Alica ◽

U&gbreve;ur Özkutlu ◽

...

Keyword(s):

Blood Pressure ◽

Methylene Blue

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Methylene blue versus vasopressin analog for refractory septic shock in the preterm neonate: A randomized controlled trial

Journal of Neonatal-Perinatal Medicine ◽

10.3233/npm-210824 ◽

2021 ◽

pp. 1-9

Author(s):

R. Ismail ◽

H. Awad ◽

R. Allam ◽

O. Youssef ◽

M. Ibrahim ◽

...

Keyword(s):

Blood Pressure ◽

Septic Shock ◽

Methylene Blue ◽

Randomized Controlled Trial ◽

Side Effects ◽

Preterm Neonate ◽

Controlled Trial ◽

Randomized Controlled ◽

Arterial Blood ◽

Refractory Septic Shock

BACKGROUND: Refractory septic shock in neonates is still associated with high mortality, necessitating an alternative therapy, despite all currently available treatments. This study aims to assess the vasopressor effect of methylene blue (MB) in comparison to terlipressin (TP) as adjuvant therapy for refractory septic shock in the preterm neonate. METHODS: A double-blinded randomized controlled trial was conducted in the Neonatal Intensive Care Units at Ain Shams University, Egypt. Thirty preterm neonates with refractory septic shock were randomized to receive either MB or TP as an adjuvant to conventional therapy. Both MB and TP were administered as an intravenous loading dose followed by continuous intravenous infusion. The hemodynamic variables, functional echocardiographic variables, and oxidant stress marker were assessed over a 24 h period together with the side effects of MB. RESULTS: MB causes significant improvement in mean arterial blood pressure with a significant decrease of the norepinephrine requirements (1.15±0.21μm/kg/min at baseline vs. 0.55±0.15μm/kg/min at 24 h). MB infusion causes an increase of the pulmonary pressure (44.73±8.53 mmHg at baseline vs. 47.27±7.91 mmHg after 24 h) without affecting the cardiac output. Serum malonaldehyde decreased from 5.45±1.30 nmol/mL at baseline to 4.40±0.90 nmol/mL at 24 h in the MB group. CONCLUSION: Administration of MB to preterm infants with refractory septic shock showed rapid increases in systemic vascular resistance and arterial blood pressure with minimal side effects.

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Methylene blue treatment of pediatric patients in the cardiovascular intensive care unit

Southwest Journal of Pulmonary and Critical Care ◽

10.13175/swjpcc022-21 ◽

2021 ◽

Vol 23 (1) ◽

pp. 8-17

Author(s):

Ashley Scheffer ◽

Keyword(s):

Blood Pressure ◽

Methylene Blue ◽

Arterial Blood Pressure ◽

Mean Arterial Blood Pressure ◽

Congenital Heart ◽

Pediatric Patients ◽

Mixed Effects ◽

Arterial Blood ◽

Blood Pressures ◽

One Year

Background: In both adults and children, hypotension related to a vasoplegic state has multiple etiologies, including septic shock, burn injury or cardiopulmonary bypass-induced vasoplegic syndrome likely due to an increase in nitric oxide (NO) within the vasculature. Methylene blue is used at times to treat this condition, but its use in pediatric cardiac patients has not been described previously in the literature. Objective: 1) Analyze the mean arterial blood pressures and vasoactive-inotropic scores of pediatric patients whose hypotension was treated with methylene blue compared to hypotensive controls; 2) Describe the dose administered and the pathologies of hypotension cited for methylene blue use; 3) Compare the morbidity and mortality of pediatric patients treated with methylene blue versus controls. Design: A retrospective chart review. Setting: Cardiac ICU in a quaternary care free-standing children’s hospital. Patients: Thirty-two patients with congenital heart disease who received methylene blue as treatment for hypotension, fifty patients with congenital heart disease identified as controls. Interventions: None. Measurements and Main Results: Demographic and vital sign data was collected for all pediatric patients treated with methylene blue during a three-year study period. Mixed effects linear regression models analyzed mean arterial blood pressure trends for twelve hours post methylene blue treatment and vasoactive-inotropic scores for twenty-four hours post treatment. Methylene blue use correlated with an increase in mean arterial blood pressure of 10.8mm Hg over a twelve-hour period (p< 0.001). Mean arterial blood pressure trends of patients older than one year did not differ significantly from controls (p=1.00), but patients less than or equal to one year of age had increasing mean arterial blood pressures that were significantly different from controls (p=0.02). Mixed effects linear regression modeling found a statistically significant decrease in vasoactive-inotropic scores over a twenty-four-hour period in the group treated with methylene blue (p< 0.001). This difference remained significant comparted to controls (p=0.003). Survival estimates did not detect a difference between the two groups (p=0.39). Conclusion: Methylene blue may be associated with a decreased need for vasoactive-inotropic support and may correlate with an increase in mean arterial blood pressure in patients who are less than or equal to one year of age.

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A SEM and Light Microscope Study of the Epidermal Leaf Structures of the Carnivorous Plant, Sarracenia purpurea, L.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065833 ◽

1971 ◽

Vol 29 ◽

pp. 358-359

Author(s):

B. J. Panessa ◽

J. F. Gennaro

Keyword(s):

Methylene Blue ◽

Toluidine Blue ◽

Outer Surface ◽

Microscope Study ◽

Light Microscope ◽

Carnivorous Plant ◽

Sarracenia Purpurea ◽

Inner Surface

Tissue from the hood and sarcophagus regions were fixed in 6% glutaraldehyde in 1 M.cacodylate buffer and washed in buffer. Tissue for SEM was partially dried, attached to aluminium targets with silver conducting paint, carbon-gold coated(100-500Å), and examined in a Kent Cambridge Stereoscan S4. Tissue for the light microscope was post fixed in 1% aqueous OsO4, dehydrated in acetone (4°C), embedded in Epon 812 and sectioned at ½u on a Sorvall MT 2 ultramicrotome. Cross and longitudinal sections were cut and stained with PAS, 0.5% toluidine blue and 1% azure II-methylene blue. Measurements were made from both SEM and Light micrographs.The tissue had two structurally distinct surfaces, an outer surface with small (225-500 µ) pubescent hairs (12/mm2), numerous stoma (77/mm2), and nectar glands(8/mm2); and an inner surface with large (784-1000 µ)stiff hairs(4/mm2), fewer stoma (46/mm2) and larger, more complex glands(16/mm2), presumably of a digestive nature.

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