PHENYTOIN

Parent or patient Information Leaflet

Dr. C. P. Ravi Kumar

Consultant Paediatric Neurologist
MRCPCH, CCT in Paediatrics (U.K.)
Fellow in Paediatric Epilepsy &
Neurology (London)

Brand names :

Tablet: Eptoin
Syrup / Liquid: Eptoin Suspension
Delayed release: Epsolin ER

Phenytoin is one of the OLDEST medicines used in epilepsy to control several different seizures or convulsions (fits), it is effective, and time tested for various types of seizures. It still remains the first line drug in controlling seizures during emergency.

Why is Phenytoin important for my child’s treatment?

It is important that your child takes Phenytoin regularly so that you child doesn’t suffer from Seizures or have fewer seizures.

Do not stop giving Phenytoin all of a sudden, as it may result in your child having more seizures.

What is Phenytoin available as?

Phenytoin is available in the preparation of Liquid medicine, Tablets, Modified-release tablets (releases medication slowly into blood after it has been consumed) in the market.

“Generic Vs Branded Drugs”

When should Phenytoin be given?

Twice a day; morning and evening. Ideally, 10-12 hours apart.

For example, anytime between 7 to 8 am and right after 12 hours between 7 to 8 pm. You can adjust the time slot according to your schedule.

However, there are some exceptions when your doctor may advise to give it thrice a day. Please follow your doctor’s instructions in such case.

It should ideally be given at the same time every day to establish a routine as it minimizes the chances of missing a dose.

What if I miss a dose?

Tablets & liquids: The child can be given the missed dose, if you remember to give it within a lapse of 6 hours. If you fail to give the missed dose within 6 hours, then might as well leave it. It is advisable to wait until the time of next routine dose.

Modified release preparations: If you miss a dose, you can give it any time within the next 8 hours. After this time, wait until the next routine dose.

Never give a double dose of Phenytoin.

If your child vomits out the content within 30 minutes of taking the medicine dosage then you can give the dose again; but if your child vomits after 30 minutes of taking the dose, then just leave it be and do not give it again.

How much of the drug should be given?

Your doctor will work out the accurate amount of Phenytoin (the dose) for your child and write the dosage in your prescription.

When you first start giving Phenytoin to your child, you are supposed to give them a small amount and then increase the dose little by little over a course of few days or weeks. This helps your child’s body to get use to the medicine. Your doctor will clarify what steps to take.

It is mandatory to follow the instructions given by your doctor about the dosage of medication.

Ultimately, when your child is free of seizures or convulsions (fits) and has no obvious side effects, you will know that the dosage is just correct.

How should I give the medicine ? “Giving Medicines”

Tablets: A whole tablet must be swallowed with a glass of water, juice or milk. You may give it by crushing and mixing it in water/ juice or small serving of yogurt / Curd.

Liquid or syrup: Use an oral syringe or a medicine spoon to measure the adequate amount. You can easily get these from any pharmacy nearby.

Do not use a kitchen teaspoon as it will not give the accurate amount of the drug.

Could this medication have any side effects on my child? Side effects

Although medicines are given to make children feel better, sometimes, they may cause some unwanted side effects.

Side effects that are commonly seen:

Gum (gingival) hypertrophy

Increase body hair

Slurred speech, double vision, drunken gait (Ataxia), and neuropathy

Excessively sleepy

Once Phenytoin is orally administered (or into blood), drug levels can be unpredictable. Example, same dose in one individual can cause sub therapeutic level (below expected blood level) and in another similar individual it can be in toxic range. Hence, it may need frequent drug level monitoring, especially if it used for long term. Your doctor will make a clinical decision and advise when required.

Side-effects that you should be aware of – Rare

Liver disease: If your child’s health deteriorates and falls sick every few hours, suffers from stomachache, skin and eyes are pale yellow in colour, feels lethargic and sleepy or increased number of seizures take them to your doctor straight away.

Other side-effects you need to be vary of

Your child may get these side-effects when they first start taking Phenytoin. They will be able to settle down within a course of week or so as their body gets used to the medicine.Continue to give sodium valproate to your child as your doctor has directed you to.

Your child feel unusually sleepy or dizzy, or their behaviour may change.

Your child may lose his/her appetite and feel like vomiting (nausea) or actually vomit. These problems can be avoided by starting with a small dose with food and gradually increasing the dosage given.

If your child starts developing skin Rash, Stop Medications right there and SEEK IMMEDIATE MEDICAL ADVICE from your DOCTOR

IF YOU NOTICE ANY SKIN RASH OR ULCERS IN MOUTH or GENITAL AREA, THEN STOP MEDICINE IMMEDIATELY AND RUSH TO HOSPITAL’S EMERGENCY DEPARTMENT.

Sometimes your child may experience other side-effects that are not listed above. If you notice any abnormalities with your child’s body or behavior, do not hesitate and immediately contact your doctor.

Despite this long list of side effects, Phenytoin is a very effective anti-epileptic (anticonvulsant) medicine and has very little effect on the child’s alertness levels, behaviour and learning abilities.

CAN WE AVOID SERIOUS SIDE EFFECT DESCRIBED ABOVE?

There is an option to check for a gene HLA – B 1502, which if present increases chance of above reaction (Stevens Johnson Syndrome), hence it’s use can be avoided.

Can other common medicines be given at the same time as Phenytoin?

Medications like ibuprofen, paracetamol, antibiotics or any of the other over the counter medicines can be given when necessary, except the ones your doctor has prohibited you from.

Consult with your doctor before giving any other medicines to your child. This includes herbal or complementary medicines.

Some other medicines used to treat epilepsy may affect how well Phenytoin works or may cause side effects. If your child is experiencing more fits or seizures, or any other side effects after using other medications, talk to your doctor immediately.

Phenytoin and pregnancy

Phenytoin may harm an unborn baby.

The oral contraceptive pill dose may need to be increased.

Where should I keep the medication?

Keep the medicine in a cupboard, secured away from heat and direct sunlight. It is not a must to keep the medicine in the refrigerator though.

Make sure the medicine is out of your child’s reach.

Store the medication in the same box it was packed in.

For more information please refer the manufacturer’s information leaflet.

References :

1. IAP Drug Formulary Web Update 2020(3) Edition 58, https://www.iapdrugformulary.com/Home
2. Consumer Medicines Information (CMI), https://www.tga.gov.au/consumer-medicines-information-cmi
3. British National Formulary for Children (BNFC)
4. Food and Drug Administration, USA https://www.fda.gov