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Drug Interactions between lidocaine and phenytoin

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

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Interactions between your drugs

Moderate

lidocaine phenytoin

Applies to: lidocaine and phenytoin

Using lidocaine together with phenytoin may cause methemoglobinemia, a rare condition that can lead to oxygen deprivation in tissues and vital organs due to reduced oxygen-carrying capacity of the blood. Individuals may be more susceptible to developing methemoglobinemia during treatment with these medications if they are very young (especially neonates and infants) or have diseases of the heart or lungs, certain genetic predispositions, or glucose-6-phosphate dehydrogenase deficiency. Medical supervision may be necessary when medications that can cause methemoglobinemia are used together. Signs and symptoms of methemoglobinemia may occur immediately or hours after treatment. Patients or their caregivers should seek immediate medical attention if they develop gray discoloration of the skin, abnormal blood coloration, nausea, headache, dizziness, lightheadedness, fatigue, shortness of breath, rapid or shallow breathing, a rapid heartbeat, palpitation, anxiety, or confusion. 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

lidocaine food

Applies to: lidocaine

Grapefruit juice may increase the blood levels of lidocaine, which may increase the risk of side effects such as low blood pressure, slow heart rate, irregular heart rhythm, difficulty breathing and convulsions. Cigarette smoking may reduce the blood levels of lidocaine, which may make the medication less effective. It is best to avoid smoking during lidocaine therapy. Consuming cruciferous vegetables (e.G., broccoli, brussels sprouts) may also reduce the blood levels of lidocaine. Talk to a healthcare professional if you have any questions or concerns. 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

phenytoin food

Applies to: phenytoin

Phenytoin levels may decrease when the suspension is given with enteral feedings. This could lead to a loss of seizure control. You could interrupt the feeding for 2 hours before and after the phenytoin dose. Alternatively, you may give the phenytoin suspension diluted in water and flush the tube with water after administration. These would make it easier for your body to absorb the medication. However, this still may not entirely avoid the interaction and may not always be feasible. You should have your phenytoin levels checked upon starting and stopping of enteral feedings. In addition, using phenytoin together with food may alter the effects of phenytoin. Contact your doctor if you experience worsening of seizure control or symptoms of toxicity, including twitching eye movements, slurred speech, loss of balance, tremor, muscle stiffness or weakness, nausea, vomiting, feeling light-headed, fainting, and slow or shallow breathing. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Ask your doctor before making any changes to your therapy.

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Therapeutic duplication warnings

Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.

Duplication

Antiarrhythmics

Therapeutic duplication

The recommended maximum number of medicines in the 'antiarrhythmics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'antiarrhythmics' category:

  • lidocaine
  • phenytoin

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

Duplication

Group i antiarrhythmics

Therapeutic duplication

The recommended maximum number of medicines in the 'group I antiarrhythmics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'group I antiarrhythmics' category:

  • lidocaine
  • phenytoin

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

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.

Medical Disclaimer