PHENYTOIN 100 MG COATED TABLETS - patient leaflet, side effects, dosage

Read all of this leaflet carefully before you start using this medicine because it contains important information for you

• – Keep this leaflet. You may need to read it again.

• – If you have further questions, please ask your doctor or pharmacist.

• – This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.

• – If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See section 4.

The name of your medicine is Phenytoin 100mg Coated Tablets. In the rest

of this leaflet it is called Phenytoin Tablets.

What is in this leaflet:

• 1. What Phenytoin Tablets are and what they are used for

• 2. What you need to know before you take Phenytoin Tablets

• 3. How to take Phenytoin Tablets

• 4. Possible side effects

• 5. How to store Phenytoin Tablets

• 6. Contents of the pack and other information

1. What Phenytoin Tablets are and what they are used for

The active ingredient in Phenytoin Tablets is called phenytoin sodium. Phenytoin belongs to a group of medicines called anticonvulsants which prevent fits.

Phenytoin Tablets are used in the control of seizures due to various types of epilepsy.

They can also be used to treat seizures during or after brain surgery and/or serious head injuries.

In addition they may also be used in the treatment of trigeminal neuralgia (face pain) if carbamazepine does not work or cannot be taken.

2. what you need to know before you take phenytoin tablets are allergic to phenytoin, other similar anticonvulsant medicines or any of the other ingredients of this medicine listed in section 6)

• are allergic to other medicines for epilepsy
• are taking medicines for HIV infection, such as delavirdine.

Warnings and precautions

Talk to your doctor or pharmacist before taking Phenytoin Tablets if you suffer from or have suffered in the past from any of the following conditions:

Liver disease

Porphyria (an inherited disease that affects haemoglobin biosynthesis) Alcohol dependence.

A small number of people being treated with anti-epileptics such as phenytoin sodium have had thoughts of harming or killing themselves. If at any time you have these thoughts, immediately contact your doctor.

Potentially life-threatening skin rashes (Stevens- Johnson syndrome, toxic epidermal necrolysis) have been reported with the use of Phenytoin, appearing initially as reddish target-like spots or circular patches often with central blisters on the trunk.

Additional signs to look for include ulcers in the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes). These potentially life-threatening skin rashes are often accompanied by flu-like symptoms. The rash may progress to widespread blistering or peeling of the skin.

The highest risk for occurrence of serious skin reactions is within the first weeks of treatment. If you have developed Stevens-Johnson syndrome or toxic epidermal necrolysis with the use of phenytoin, you must not be re-started on phenytoin at any time.

If you develop a rash or these skin symptoms, stop taking Phenytoin Tablets, seek urgent advice from a doctor and tell him that you are taking this medicine.

This risk of these serious skin side effects may be associated with a variant in genes in a subject of Chinese or Thai origin. If you are of such origin and have been tested positively carrying this genetic variant (HLA-B*1502), discuss this with your doctor before taking Phenytoin Tablets.

Phenytoin may affect the breakdown of the sugar, glucose, and may prevent the release of the hormone, insulin which could lead to high blood sugar. This is particularly important if you are diabetic.

Black patients may be at greater risk of loiver problems, serious skin reactions and allergic reactions.

Warnings and precautions

• have liver, kidney or thyroid problems
• if you suffer from absence (petit mal) seizures or myoclonic seizures (brief, shock-like jerks of a muscle or group of muscles)
• if you are currently taking an alternative antiepileptic
• are being fed through a tube or into a vein
• suffer from diabetes mellitus
• are an alcoholic
• suffer from any blood disorders
• have a fever with a temperature above 38°C for more than 24 hours
• are elderly (aged 65 years or older) or the patient is a neonate (a newborn infant aged less than four weeks)
• are suffering from a long term or chronic illness
• have porphyria
• have a high level of urea in the blood (uraemia)
• suffer from AIDS and have kidney problems or a low blood albumin level
• are pregnant, planning to become pregnant or you are breast feeding.

If any of the above statements apply to you, you should speak to your doctor before taking Phenytoin Tablets.

You should make sure you have enough vitamin D in your diet, or get enough exposure to sunshine, while taking Phenytoin Tablets.

Required tests

If you are required to have blood tests for any reasons other than your treatment with phenytoin, you should let your doctor or nurse know you are taking this medication since Phenytoin Tablets may interfere with various laboratory tests including tests for liver and thyroid function and blood sugar levels.

You will be required to have regular blood tests when you are taking these tablets and your liver and thyroid will be monitored.

You will also need to have tests to monitor your brain function and physical examinations including dental check-ups.

Other medicines and Phenytoin Tablets

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines or herbal products, even those you may have bought yourself without a prescription.

Please particularly check with your doctor if you are taking or need to take any of the following:

Other medicines used to treat epilepsy:

• such as sodium valproate, clonazepam, oxcarbazepine, carbamazepine, lamotrigine, tiagabine, topiramate, phenobarbital, ethosuximide, primodone and vigabatrin

Medicines that help your nervous system or brain:

levodopa used to treat Parkinson’s Disease

• medicines used to treat depression such as bupropion, tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), maprotiline, fluoxetine, sertraline, fluvoxamine, trazodone, viloxazine, mianserin and paroxetine
• medicines used to treat anxiety such as diazepam, chlordiazepoxide, clonazepam or other benzodiazepines
• medicines used to treat sleeplessness, depression and psychiatric disorders such as clozapine, quetiapine, sertindole, haloperidol, phenothiazines, thioxanthines, loxapine, and lithium
• the herbal remedy St John’s wort (Hypericum perforatum).

Medicines that fight infections:

• antibiotics such as isoniazid, chloramphenicol, clarithromycin, cycloserine, metronidazole, co-trimoxazole, trimethoprim, other sulphonamides, rifamycin, rifampicin and doxycycline, sulfadiazine, sulfamethiazole, sulfamethoxazole – trimethoprim, sulfaphenazole, sulfisoxazole, ciprofloxacin
• medicines used to treat fungal infections e.g. miconazole, fluconazole, ketoconazole, Amphotericin B, voriconazole, posaconazole and itraconazole
• medicines used to treat virus infections such as indinavir, nelfinavir,

lopinavir, saquinavir and zidovudine

• medicines used to treat malaria e.g. pyrimethamine
• influenza (flu) virus vaccine

Medicines to treat cardiovascular or lung problems:

quinidine, disopyramide, cardiac glycosides (e.g. digoxin and digitoxin)

• medicines to treat high blood pressure e.g. diazoxide, diltiazem, nifedipine,

verapamil, felodipine, isradipine, nisoldipine and nicardapine

• medicines to prevent blood clots e.g. coumarin, nicoumalone, dicoumarol, warfarin and ticlopidine
• acetazolamide, a diuretic (water tablet), also used for mountain sickness
• medicines used to treat breathing difficulties including asthma and bronchitis, such as theophylline

Medicines to treat gastric problems:

• medicines used to treat stomach ulcers e.g. cimetidine, esomeprazole, omeprazole and sucralfate, ranitidine, famotidine and some antacids.
• medicines containing calcium including antacids used to treat indigestion (take them two to three hours before or after taking your phenytoin tablets)

Anti cancer medicines:

• methotrexate, bleomycin, carmustine, cisplatin, vinblastine, capecitabine, fluorouracil, levamisonle, busulfan, etoposide and imatinib.
• toremifene and tamoxifen, used to treat breast cancer

Alcohol and drugs of abuse:

• alcohol
• medicines used to treat alcohol abuse e.g. disulfiram
• medicines to treat drug abuse e.g. methadone

Other medicines:

• hormone containing medicines including oestrogens, oral contraceptives (the birth control pill), gestrinone and tibolone
• medicines used for pain relief and inflammation such as aspirin, paracetamol, phenylbutazone or other non-steroidal anti-inflammatory drugs, or azapropazone. (Do not take Phenytoin Tablets if you are taking azapropazone)
• levothyroxine used to treat thyroid problems
• steroids, used to treat a variety of conditions e.g. fludrocortisone, dexamethasone, methylprednisolone, prednisolone, prednisone and other glucocorticoids.
• medicines used to treat diabetes including tolbutamide and repaglinide. (Do not take Phenytoin Tablets if you are taking repaglinide)
• anaesthetics (enfluane, halothane and methoxyflurane)

Phenytoin Tablets with alcohol

Your Phenytoin Tablets may not work properly if you drink alcohol whilst taking them.

Pregnancy and breast-feeding

You should speak to your doctor about your epilepsy treatment if you are planning to become pregnant. If you get pregnant whilst taking Phenytoin Tablets you should tell the doctor straight away. It is important that your epilepsy remains well controlled but as with other antiepilepsy treatments, phenytoin can damage the nervous system of unborn babies as well as cause other effects. Your doctor may advise you to take extra folic acid if you’re planning to become pregnant and while you’re pregnant. If taken during pregnancy Phenytoin

Tablets may also cause bleeding in the infant and mother. The risk of this may be reduced by the administration of vitamin K around the time of delivery.

Phenytoin passes into breast milk.

Breastfeeding is not recommended while taking phenytoin.

You should speak to your doctor if you wish to breast-feed whilst taking Phenytoin Tablets

Driving and using machines

You will need to discuss with your doctor whether you should drive or operate machinery, which will depend on how well your fits are controlled. Phenytoin Tablets may cause you to feel drowsy, dizzy or uncoordinated. If you experience any of these symptoms, you should not drive or operate machinery.

Phenytoin Tablets contain sucrose

If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product.

3. how to take phenytoin tablets

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

Unless instructed differently, take your tablets with a glass of water.

Adults

The starting dose of Phenytoin Tablets in adults and the elderly varies from person to person and depends on body weight, but is usually 3 to 4mg/kg.

The usual maintenance dose is 200 to 500mg daily as a single or divided doses.

Children and infants

The starting dose of Phenytoin Tablets in children and infants depends on body weight, but is usually 5mg/kg in two or three doses. The usual maintenance dose is 4 to 8mg/kg daily in divided doses. The maximum dose is 300mg a day.

Neonates (Infants aged less than four weeks)

It is important that the levels of phenytoin are measured since the absorption of phenytoin in neonates is variable.

Elderly

The same doses may be given as for other adults unless you have liver or kidney problems or a low albumin level in your blood.

These doses may be adjusted by your doctor.

Patients with liver problems

If you have liver problems a reduced dose will be given.

If you take more Phenytoin Tablets than you should

If you take more Phenytoin Tablets than you should, contact your doctor, pharmacist or nearest hospital casualty department immediately. Take this leaflet and any remaining tablets with you.

If you accidentally take too many tablets, initially you may have blurred vision, involuntary movement of the eyes from side to side, loss of coordination, fits and slurred speech. This may be followed by unconsciousness, enlarged or fixed pupils and low blood pressure.

Serious breathing and blood circulation problems can be life-threatening.

If you forget to take Phenytoin Tablets

If you miss a dose of Phenytoin Tablets, take another dose as soon as you remember. If it is almost time for your next dose, then do not take the missed dose at all. Do not take a double dose to make up for a forgotten dose.

Stopping Phenytoin Tablets

Do not stop taking this medicine without speaking to your doctor first.

Phenytoin Tablets should be withdrawn slowly as sudden withdrawal may cause your fits/epilepsy to reoccur.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them. Potentially life-threatening skin rashes (Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported rarely (see section 2).

If you experience any of the following side effects, contact your doctor immediately:

• fever, sore throat, mouth ulcers, bruising or bleeding which may be caused by blood disorders
• rash or acne, particularly if associated with fever, redness and blistering of the skin (this can also affect the mouth and tongue)
• sudden wheeziness, difficulty in breathing, swelling of the eyelids, face or lips, rash or itching (especially affecting the whole body) as this may be due to an allergic reaction
• yellowing of the skin and/or whites of the eyes which may be due to a liver reaction
• large lymph glands, since these can be a sign of cancer of the lymph system

Other side effects to tell your doctor about immediately include:

• involuntary movement of the eyes from side to side
• seeing double
• more frequent seizures
• high blood sugar (which may cause extreme thirst)
• loss of coordination, slurred speech, confusion and twitching (‘tics’)
• involuntary movements or spasms (muscle contractions)
• shaking
• pins and needles or numbness of your hands and fingers or the loss of the sensation of pain
• effects on mental function and the ability to think (especially in children)

If you get any of the above side effects, you should tell your doctor immediately, since the level of phenytoin in your blood may be too high.

Common side effects include:

• loss of appetite
• headache
• dizziness
• nervousness
• sleeping problems
• drowsiness
• feeling sick
• being sick
• constipation
• gum problems (particularly in younger patients)
• increased body hair in females.

Other side effects include:

• enlargement of facial features
• enlargement of lips
• men may experience genital pain or abnormal bending of the penis when sexually aroused (Peyronie’s di­sease), or breast enlargement
• fatigue (feeling tired), feeling unwell, flu like symptoms, muscle or joint pains, or lumps on your legs
• hepatitis (a liver disease) or other liver problems
• kidney problems
• lung problems
• bent fingers (Dupuytrens’ contracture)
• bone problems due to low levels of calcium or vitamin D
• swelling of glands around the mouth
• increased levels of cholesterol or triglycerides in your blood

There have been reports of bone disorders including osteopenia and osteoporosis (thinning of the bone) and fractures. Check with your doctor or pharmacist if you are on long-term antiepileptic medication, have a history of osteoporosis, or take steroids.

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme atBy reporting side effects you can help provide more information on the safety of this medicine.

5. how to store phenytoin tablets do not use this medicine after the expiry date which is stated on the packet. the expiry date refers to the last day of that month.

• The tablets should not be used if they show any signs of deterioration such as discolouration.
• Phenytoin Tablets should not be stored above 25°C. The tablets should be kept in their original container, in order to protect from moisture. Do not transfer the tablets to another container.
• Two desiccants have been placed on top of the tablets. These are not to be eaten;

6. contents of the pack and other informationthe active substance is phenytoin sodium.

92mg of phenytoin is equivalent to 100mg of phenytoin sodium.

The other ingredients are icing sugar, calcium hydrogen phosphate, sucrose, purified water, magnesium stearate, Byco-C (gelatin), titanium dioxide (E171), sucrose, talc and Opaglos 6000P (E901, E903, E904).

What Phenytoin Tablets look like and contents of the pack

The tablets are white, circular, sugar coated tablets that are rounded on both sides.

The registered pack sizes are 100, 250, 500, 1000 and 5000 tablets in polyethylene/po­lypropylene containers.

Not all pack sizes may be marketed.

Other formats

To listen to or request a copy of this leaflet in Braille, large print or audio please call, free of charge: 0800 198 5000 (UK Only)

Please be ready to give the following information:

Product Name	Reference Number
Phenytoin 100mg Coated Tablets	PL 55539/0027

This is a service provided by the Royal National Institute of Blind People.

Marketing Authorisation Holder and Manufacturer

Marketing Authorisation Holder: SNIGD (UK Limited), Office Gold, Building 3

Chiswick Park, 566 Chiswick High Road, London, England, W4 5YA

Manufacturer: CP Pharmaceuticals Ltd, Ash Road North, Wrexham, LL13 9UF, UK.

This leaflet was last revised in October 2021