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Drug Interactions between fosphenytoin and Relcof C

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

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Interactions between your drugs

Moderate

codeine fosphenytoin

Applies to: Relcof C (codeine / guaifenesin) and fosphenytoin

Fosphenytoin may reduce the blood levels of codeine, which may make codeine less effective in treating your condition. Additionally, if you have been receiving treatment with codeine, adding fosphenytoin may cause you to experience unpleasant withdrawal symptoms such as excessive sweating, chills, flushing, restlessness, irritability, anxiety, tremor, rapid heartbeat and nausea. On the other hand, if you have been receiving both medications, suddenly discontinuing fosphenytoin may increase the blood levels of codeine, which could increase or prolong its adverse effects. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both 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

codeine food

Applies to: Relcof C (codeine / guaifenesin)

Do not use alcohol or medications that contain alcohol while you are receiving treatment with codeine. This may increase nervous system side effects such as drowsiness, dizziness, lightheadedness, difficulty concentrating, and impairment in thinking and judgment. In severe cases, low blood pressure, respiratory distress, fainting, coma, or even death may occur. With certain long-acting formulations of narcotic pain medication, consumption of alcohol may also cause rapid release of the drug, resulting in high blood levels that may be potentially lethal. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. Do not use more than the recommended dose of codeine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication 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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