Phenytoin - Dosage and How to Use
Skip Ribbon Commands
Skip to main content


Drug Class: Commonly Known As: Category:

Phenytoin - Dosage and How to Use

How should Phenytoin be used?

  • Follow the instructions on your medication label and take the medication as prescribed by your doctor.
  • You should take this medication with or after food. TakePphenytoin two hours apart from a high-protein meal (e.g. with milk or meat), otherwise its efficacy may be reduced.
  • If you are taking the capsules, swallow capsules whole with a glass of water. Do not take capsules that are discoloured.
  • If you are using oral liquid form/suspension, shake the bottle well before taking. Use a medicine spoon ​or graduated syringe to measure your medication. Do not use household spoons as they may not be accurate.​
  • You may not experience any effect immediately after starting the medication as it may take up to a few weeks before this medication works fully. You should continue to take your medication regularly as instructed by your doctor even if you feel well. Stopping your medication without informing your healthcare professional may cause your condition to become worse quickly.
  • Do not stop taking or adjust the dose of this medication without consulting your healthcare professional. Do not change the medication that was dispensed to you without informing your healthcare professional.

What should I do if I miss a dose?

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for your next dose, take only the usual dose. Do not double your dose or use extra medicine to make up for the missed dose.

What should I do if I overdose?

  • Updated on 3/31/2022 12:00:00 AM
  • Article contributed by PSS National Medication Information Workgroup PSS National Medication Information Workgroup
The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth

Find Your Medicines