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Drug Interactions between guanfacine and prazosin

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

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Interactions between your drugs

Moderate

prazosin guanFACINE

Applies to: prazosin and guanfacine

Using guanFACINE and prazosin together can have increased effects on your blood pressure. The blood pressure lowering effects of this combination may be additive. You may be more likely to experience side effects such as dizziness, weakness, headache, flushing, fainting, and irregular heartbeat. You may need a dose adjustment or more frequent monitoring of your blood pressure to safely use both medications. Avoid driving or operating hazardous machinery until you know how these medications affect you, and use caution when getting up from a sitting or lying position. 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

Major

guanFACINE food

Applies to: guanfacine

Avoid consuming grapefruit or grapefruit juice during treatment with guanFACINE, as it may increase blood levels and effects of the medication. This may cause blood pressure to fall excessively, especially when you rise from a sitting or lying position. The risk of other side effects such as drowsiness, dizziness, lightheadedness, fainting, headache, palpitations, and heart rate changes may also increase. Additionally, you should avoid or limit the use of alcohol while being treated with guanFACINE. Combining the medication with alcohol can intensify sedative and blood pressure lowering effects, which may increase the risk of falls and injury. Avoid driving or operating hazardous machinery until you know how the medication affects you, and use caution when getting up from a sitting or lying position. If you are using a long-acting or extended-release formulation of the medication, make sure you do not take it with a high-fat meal. Doing so results in increased absorption and elevated blood levels of the medication. Talk to your doctor or pharmacist if you have any questions or concerns.

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Moderate

prazosin food

Applies to: prazosin

Ask your doctor before using prazosin together with ethanol (alcohol). Using prazosin with ethanol (alcohol) can lower your blood pressure. This can cause dizziness or feeling like you might pass out, especially when getting up from a sitting or lying position. This may be more likely to occur when you first start taking either of these medications. You may need a dose adjustment or need your blood pressure checked more often if you take both medications. You may develop flushing, warmth or redness under your skin or tingly feeling after alcohol intake (especially in you are of Asian descent) and should be advised to avoid alcohol or limit your intake. 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.

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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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