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Drug Interactions between Phenavent PED and hyoscyamine / methenamine / methylene blue / phenyl salicylate

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

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Interactions between your drugs

Major

phenylephrine methylene blue

Applies to: Phenavent PED (guaifenesin / phenylephrine) and hyoscyamine / methenamine / methylene blue / phenyl salicylate

Using methylene blue together with phenylephrine is not recommended. Combining these medications can cause dangerously high blood pressure and even death. You may use phenylephrine only after you have been off methylene blue for at least 14 days. You should seek immediate medical attention if you experience sudden and severe headache, blurred vision, confusion, seizures, chest pain, nausea or vomiting, sudden numbness or weakness (especially on one side of the body), speech difficulties, fever, sweating, lightheadedness, and/or fainting during treatment with methylene blue, as these may be signs and symptoms of excessively high blood pressure. 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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Moderate

phenylephrine hyoscyamine

Applies to: Phenavent PED (guaifenesin / phenylephrine) and hyoscyamine / methenamine / methylene blue / phenyl salicylate

Hyoscyamine may increase the effects of phenylephrine on your blood pressure and heart rate. Before receiving these medications, you should let your doctor know if you have high blood pressure or heart disease. You may not be able to use one or both of these medications, or you may need closer monitoring by your doctor in order to use these medications. 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

Moderate

hyoscyamine food

Applies to: hyoscyamine / methenamine / methylene blue / phenyl salicylate

Ask your doctor before using hyoscyamine together with ethanol. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking hyoscyamine. You should be warned not to exceed recommended dosages and to avoid activities requiring mental alertness. If your doctor prescribes these medications together, you may need a dose adjustment to safely take this combination. 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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Moderate

phenylephrine food

Applies to: Phenavent PED (guaifenesin / phenylephrine)

Both phenylephrine and caffeine can increase blood pressure and heart rate, and combining them may enhance these effects. Talk to your doctor before using these medications, especially if you have a history of high blood pressure or heart disease. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if your condition changes or you experience increased side effects. 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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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.

See also

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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.

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