I found this on Wikipedia about the blue in prosed... there is much more there about it if you look it up
http://en.wikipedia.org/wiki/Methylene_blue
Medicine
Methylene blue is a monoamine oxidase inhibitor (MAOI),[5] and if infused intravenously at doses exceeding 5 mg/kg, may precipitate serious serotonin toxicity, serotonin syndrome, if combined with any selective serotonin reuptake inhibitors (SSRIs) or other serotonin reuptake inhibitor (e.g., duloxetine, sibutramine, venlafaxine, clomipramine, imipramine).[6]
YIKES (my comment - but only injected?)
Methylene blue is also structurally similar to the chlorpromazine and the typical antipsychotics. It is the basic compound from which chlorpromazine and many other antipsychotics are made.[7]
Methylene blue is a component of a frequently prescribed urinary analgesic/anti-infective/anti-spasmodic known as "Prosed", which also contains methanamine, hyoscyamine sulfate, and salicylate. A similar, more popular combination medication known as "Urised" (and its generic counterparts) was discontinued in 2007, quite possibly because of the way in which methanamine was included into the formulation (and its ease of separation from the other components of the medication), and the fact that methanamine is a precursor to methamphetamine, making it a target for clandestine use. The new formulation ("Prosed") sequesters the methanamine using a method which makes its separation nearly impossible.
http://en.wikipedia.org/wiki/Methylene_blue
Medicine
Methylene blue is a monoamine oxidase inhibitor (MAOI),[5] and if infused intravenously at doses exceeding 5 mg/kg, may precipitate serious serotonin toxicity, serotonin syndrome, if combined with any selective serotonin reuptake inhibitors (SSRIs) or other serotonin reuptake inhibitor (e.g., duloxetine, sibutramine, venlafaxine, clomipramine, imipramine).[6]

Methylene blue is also structurally similar to the chlorpromazine and the typical antipsychotics. It is the basic compound from which chlorpromazine and many other antipsychotics are made.[7]
Methylene blue is a component of a frequently prescribed urinary analgesic/anti-infective/anti-spasmodic known as "Prosed", which also contains methanamine, hyoscyamine sulfate, and salicylate. A similar, more popular combination medication known as "Urised" (and its generic counterparts) was discontinued in 2007, quite possibly because of the way in which methanamine was included into the formulation (and its ease of separation from the other components of the medication), and the fact that methanamine is a precursor to methamphetamine, making it a target for clandestine use. The new formulation ("Prosed") sequesters the methanamine using a method which makes its separation nearly impossible.
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