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Drug Interactions between 5-HTP and hyoscyamine / methenamine / methylene blue / phenyl salicylate

This report displays the potential drug interactions for the following 2 drugs:

  • 5-HTP (5-hydroxytryptophan)
  • hyoscyamine/methenamine/methylene blue/phenyl salicylate

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Interactions between your drugs


methylene blue 5-hydroxytryptophan

Applies to: hyoscyamine / methenamine / methylene blue / phenyl salicylate and 5-HTP (5-hydroxytryptophan)

Using methylene blue together with 5-hydroxytryptophan is not recommended. Combining these medications can increase the risk of a rare but serious condition called the serotonin syndrome, which may include symptoms such as confusion, hallucination, seizure, extreme changes in blood pressure, increased heart rate, fever, excessive sweating, shivering or shaking, blurred vision, muscle spasm or stiffness, tremor, incoordination, stomach cramp, nausea, vomiting, and diarrhea. Severe cases may result in coma and even death. In general, you should wait at least 14 days after stopping methylene blue before you start treatment with 5-hydroxytryptophan. Conversely, if you have recently been on 5-hydroxytryptophan and are now starting treatment with methylene blue, you should check with your doctor or pharmacist to see how long you should wait before it is safe for you to use methylene blue, as some medications can take a while to clear from your body. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Drug and food interactions

No results found in our database - however, this does not necessarily mean no interactions exist. Always consult with your doctor or pharmacist.

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.