Phenitoinum Vzf

Leaflet attached to the packaging: patient information

PHENYTOINUM WZF, 100 mg, tablets

Phenytoinum

Please read carefully the contents of the leaflet before using the medicine, as it contains important information for the patient.

• Please keep this leaflet, so that you can read it again if necessary.
• In case of any doubts, you should consult a doctor or pharmacist.
• This medicine has been prescribed specifically for you. Do not pass it on to others.
• The medicine may harm another person, even if their symptoms are the same.
• If the patient experiences any side effects, including any side effects not listed in this leaflet, they should tell their doctor or pharmacist. See section 4.

Table of contents of the leaflet

• 1. What is Phenytoinum WZF and what is it used for
• 2. Important information before using Phenytoinum WZF
• 3. How to use Phenytoinum WZF
• 4. Possible side effects
• 5. How to store Phenytoinum WZF
• 6. Contents of the packaging and other information

1. What is Phenytoinum WZF and what is it used for

The medicine contains phenytoin, a substance with antiepileptic action. Phenytoin prevents the occurrence and reduces the frequency of generalized epileptic seizures. It also reduces the frequency of partial seizures and prevents their generalization, and prevents the spread of pain impulses in trigeminal neuralgia. Phenytoinum WZF is used:

• in epilepsy (generalized seizures, complex partial seizures);
• to prevent epileptic seizures after neurosurgical operations and head injuries;
• in trigeminal neuralgia - only if carbamazepine has proven ineffective or in case of hypersensitivity (intolerance) to carbamazepine.

2. Important information before using Phenytoinum WZF

When not to use Phenytoinum WZF:

• if the patient is allergic to phenytoin or other hydantoin derivatives, or any of the other ingredients of this medicine (listed in section 6);
• if the patient has been diagnosed with porphyria.

Warnings and precautions

Before starting to use Phenytoinum WZF, you should discuss it with your doctor or pharmacist. In diabetic patients, phenytoin may affect glucose metabolism and inhibit insulin secretion, leading to an increase in blood glucose levels. Phenytoin may cause or exacerbate absence seizures or myoclonic seizures.

After using phenytoin, life-threatening skin reactions have been reported (Stevens-Johnson syndrome, toxic epidermal necrolysis). These reactions initially have the form of red spots or round patches on the torso, often with blisters in their center. Additional symptoms include ulcers in the mouth, throat, nose, and on the genitals and conjunctiva (red and swollen eyes). These potentially life-threatening skin rashes are often accompanied by flu-like symptoms. The rash may transform into widespread blisters on the skin or peeling of the skin.

These serious skin reactions are more common in the first few weeks of treatment.
If a patient has developed Stevens-Johnson syndrome or toxic epidermal necrolysis after taking phenytoin, they should never use this medicine again.
If a patient develops a rash or the above-mentioned skin symptoms, they should urgently consult a doctor and inform them that they are taking this medicine.

During the use of Phenytoinum WZF, serious skin reactions are rare. However, this risk may be associated with a specific genetic mutation in patients of Chinese or Thai origin. Patients of such origin who have previously been found to have this genetic variant (HLA-B*1502) should discuss this with their doctor before taking Phenytoinum WZF. If a patient is of Taiwanese, Japanese, Malaysian, or Thai origin, and the test results show that they are carriers of the CYP2C9*3 genetic variant, they should discuss this with their doctor before taking Phenytoinum WZF. In patients with both generalized and partial seizures of the "absence" type, the doctor may recommend the use of other medicines in addition to phenytoin. Disorders such as confusion (symptoms: impaired consciousness, disorientation, deep disturbances of thought, motor excitement with uncontrolled movements) may be early symptoms of phenytoin toxicity and indicate that too high a dose of the medicine has been used. You should contact your doctor, who will decide whether to reduce the dose of phenytoin or discontinue the medicine. Phenytoin may interfere with vitamin D metabolism. In case of insufficient vitamin D supplementation or insufficient exposure to sunlight, bone demineralization, decreased calcium levels in the blood, or rickets may occur. During the use of the medicine, it is not recommended to use herbal preparations containing St. John's Wort (Hypericum perforatum) in their composition, as it may reduce the effectiveness of phenytoin. If you are using preparations containing St. John's Wort, you should consult your doctor before discontinuing them. Phenytoin may affect the results of some laboratory tests (e.g., glucose measurement, alkaline phosphatase, calcium levels, folic acid, thyroxine). In patients with liver function disorders who are taking phenytoin, toxic effects of phenytoin may occur due to excessive accumulation of the medicine in the body. Therefore, in these patients, the doctor will recommend reducing the dose of the medicine. Caution should be exercised when using the medicine in elderly patients - the dose of phenytoin is determined by the doctor individually for each patient, taking into account the use of other medicines. Elderly patients usually require smaller doses of the medicine. If Phenytoinum WZF is used during pregnancy, there is a risk of fetal damage. Women of childbearing age should use effective contraception during the use of Phenytoinum WZF (see "Pregnancy and breastfeeding").

Phenytoinum WZF and other medicines

You should tell your doctor or pharmacist about all medicines you are currently taking or have recently taken, as well as any medicines you plan to take. Phenytoin affects the action of various medicines, so during a consultation with a doctor, regardless of their specialty, you should inform them that you are taking this medicine. The doctor may recommend a blood test to check the effect of other medicines on phenytoin levels.

• Phenytoin may affect the action of medicines used:
• in epilepsy - carbamazepine, lamotrigine, sodium valproate, valproic acid, succinimides (e.g., ethosuximide), vigabatrin, phenobarbital;
• in fungal infections - e.g., amphotericin B, fluconazole, itraconazole, ketoconazole, miconazole;
• in tuberculosis and other infections - chloramphenicol, isoniazid, rifampicin, sulfonamides, doxycycline, ciprofloxacin;
• in asthma and bronchitis - theophylline;
• in pain and inflammatory conditions - phenylbutazone, salicylate derivatives, corticosteroids;
• in gastric ulcer disease - omeprazole, sucralfate, some antacids, and H2 receptor antagonists (e.g., cimetidine, ranitidine, famotidine);
• in sleep disorders, depression, and mental disorders - chlordiazepoxide, clozapine, diazepam, disulfiram, fluoxetine, methylphenidate, paroxetine, phenothiazine derivatives, trazodone, tricyclic antidepressants, and viloxazine;
• in cancer - anticancer drugs;
• in autoimmune diseases - cyclosporine;
• in heart and circulatory system disorders - amiodarone, reserpine, digitoxin, furosemide, quinidine, and oral anticoagulants from the vitamin K antagonist group (e.g., dicumarol, warfarin), and calcium channel blockers (e.g., diltiazem, nifedipine);
• in diabetes - tolbutamide;
• in hormone replacement therapy (estrogens), in contraception (oral contraceptives);
• in anesthesia (halothane), during surgical procedures (muscle relaxants);
• Medicines whose serum concentration and/or action may be reduced by phenytoin:
• oral anticoagulants from the direct thrombin or factor Xa inhibitor group, e.g., rivaroxaban, dabigatran, apixaban, edoxaban;
• lacosamide;
• tikagrelor.
• In addition, phenytoin affects the action of methadone, folic acid, and vitamin D.
• It is not recommended to use phenytoin simultaneously with herbal preparations containing St. John's Wort (Hypericum perforatum) in their composition, as it may reduce the effectiveness of phenytoin. If you are using preparations containing St. John's Wort, you should consult your doctor before discontinuing them. Phenytoin may affect the results of some laboratory tests (e.g., glucose measurement, alkaline phosphatase, calcium levels, folic acid, thyroxine).

Phenytoinum WZF and alcohol

Alcohol consumed during the use of phenytoin affects the concentration of the medicine in the blood. During the use of the medicine, you should not drink alcohol, as it may lead to fluctuations in phenytoin levels in the blood (initially an increase, and with chronic alcohol abuse - a decrease in levels).

Pregnancy and breastfeeding

If you are pregnant or breastfeeding, think you may be pregnant, or plan to have a child, you should consult your doctor or pharmacist before using this medicine. Phenytoin used during pregnancy may cause birth defects, but these defects may also be caused by epilepsy and genetic factors. Phenytoinum WZF may cause serious birth defects. If you are taking Phenytoinum WZF during pregnancy, your fetus is up to 3 times more likely to have birth defects than the fetuses of women who do not take antiepileptic drugs. Serious birth defects have been reported, including growth disorders and birth defects of the skull, face, nails, fingers, and heart. Some of these may occur together as developmental disorders occurring in the course of the so-called fetal hydantoin syndrome. In infants born to mothers who used phenytoin during pregnancy, cases of neurodevelopmental disorders (related to brain development) have been reported. The results of some studies have shown that phenytoin has a negative effect on the neurological development of unborn children exposed to this medicine, while the results of other studies have not shown such an effect. However, it cannot be ruled out that phenytoin has a negative effect on neurological development. Women of childbearing age who do not plan to become pregnant should use effective contraception during the use of Phenytoinum WZF. Phenytoinum WZF may affect the action of hormonal contraceptives, such as birth control pills, and reduce their effectiveness in preventing pregnancy. To choose the most suitable contraceptive method to be used during the use of Phenytoinum WZF, you should consult your doctor. Women of childbearing age who plan to become pregnant should discuss changing their treatment to other suitable methods with their doctor before stopping contraception and becoming pregnant. If you are pregnant or think you may be pregnant, you should immediately tell your doctor. You should not stop taking the medicine without first discussing it with your doctor. Stopping the use of the medicine without consulting a doctor may cause seizures, which can pose a risk to your health and the health of your unborn child. The doctor may decide to change the treatment. Phenytoin may be used during pregnancy only if the doctor decides that the benefit to the mother outweighs the risk to the fetus. During the use of phenytoin in pregnancy, the doctor will recommend periodic measurement of phenytoin levels in the blood to adjust the dosage according to the patient's condition. It is not recommended to use phenytoin during breastfeeding, and women taking phenytoin should not breastfeed.

Driving and operating machinery

The medicine may impair psychophysical abilities - during its use, you should not drive vehicles or operate machinery.

3. How to use Phenytoinum WZF

This medicine should always be used in accordance with the doctor's recommendations. In case of doubts, you should consult a doctor or pharmacist. The dosage of phenytoin is determined by the doctor individually for each patient. In some cases, it may be necessary to monitor the level of the medicine in the blood, especially after changing the dose or if there is a suspicion of drug interactions. A steady state of phenytoin in the blood is achieved after 7-10 days, so you should not make any changes to the dosage earlier than after this period. Usually, the following dosage is used:

Adults

For the first 7 days, 300 mg per day in three divided doses. Every 7-10 days, the dose can be increased or decreased to a maintenance dose of 300 mg to 400 mg per day. Some patients may require up to 600 mg per day. In trigeminal neuralgia - usually 400 mg to 500 mg per day.

Children

From 3 to 8 mg/kg body weight in divided doses, the total daily dose should not exceed 300 mg. If it is not possible to divide the doses into equal parts, the larger dose should be given before bedtime.

Using a higher dose of Phenytoinum WZF than recommended

In case of using a higher dose of Phenytoinum WZF than recommended, the following may occur: nystagmus, coordination disorders, speech disorders. After significant overdose, coma, respiratory disorders (including apnea), and death may occur. Treatment: the doctor will consider gastric lavage and apply appropriate symptomatic treatment (there is no specific antidote).

Missing a dose of Phenytoinum WZF

In case of missing a dose of Phenytoinum WZF, you should take it as soon as possible. If the time for the next dose is approaching, you should skip the missed dose and take the next one according to the established schedule. You should not take a double dose to make up for the missed dose.

Stopping the use of Phenytoinum WZF

If it is necessary to reduce the dose of the medicine or discontinue it completely, changes to the dosage should be made gradually, only on the doctor's instructions, as sudden discontinuation of phenytoin treatment in patients with epilepsy may cause a seizure. In case of an allergic reaction to the medicine, it may be necessary to discontinue it - in such a case, you should immediately contact your doctor, who will recommend another antiepileptic medicine. If you have any further doubts about the use of this medicine, you should consult a doctor or pharmacist, or a nurse.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them. Blood and lymphatic system disorders Rare, sometimes life-threatening blood disorders:

• decreased platelet count (thrombocytopenia),
• decreased white blood cell count (leukopenia),
• decreased granulocyte count (granulocytopenia) or granulocytopenia, manifesting as throat and oral mucosa ulcers and fever,
• deficiency of all normal blood cell elements (pancytopenia),
• anemia,
• increased red blood cell count (macrocytosis),
• enlarged lymph nodes (local and generalized), including benign lymph node hyperplasia and other lymph node changes; possible symptoms: fever, rash, liver function disorders. In case of lymph node enlargement, you should immediately consult a doctor.
• decreased red blood cell count (pure red cell aplasia) - frequency not known.

Immune system disorders

• hypersensitivity syndrome, sometimes life-threatening, characterized by: joint pain, increased eosinophil count, fever, liver function disorders, lymph node enlargement, or rash,
• systemic lupus erythematosus,
• giant cell arteritis,
• immunoglobulin disorders (antibodies).

Nervous system disorders

• nystagmus (uncontrolled eye movements),
• slurred speech,
• disorientation,
• sensory disturbances (e.g., tingling, prickling, burning),
• drowsiness, dizziness, insomnia,
• irritability,
• headache,
• coordination disorders and other movement disorders (rarely) (including involuntary muscle contractions, e.g., of the trunk and arms - athetosis), muscle tone disorders, hand tremors, short, mild muscle contractions (fasciculations),
• irreversible cerebellar disorders, occasionally after severe phenytoin overdose,
• peripheral nerve damage (in patients taking phenytoin for a long time),
• aggression or sedation, memory impairment, and depression.

Gastrointestinal disorders

• nausea, vomiting, constipation,
• toxic hepatitis (rarely), liver damage.

Skin and subcutaneous tissue disorders

• various forms of skin rash (urticarial or erythematous, sometimes with accompanying fever),
• blistering or exfoliative skin inflammation,
• systemic lupus erythematosus (severe skin and internal organ disease).

Life-threatening skin rashes (Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported (see section 2). They occurred very rarely.

Musculoskeletal and connective tissue disorders

• bone disorders, including osteopenia and osteoporosis (decreased bone mineral density) and fractures. You should consult your doctor if you have been taking antiepileptic drugs for a long time, have had osteoporosis, or are taking steroids.
• coarsening of facial features, lip enlargement, gum hyperplasia, excessive body hair,
• Peyronie's disease (erectile dysfunction) (rarely),
• Dupuytren's contracture.

Other

• polyarthropathy (disorders affecting multiple joints),
• interstitial nephritis,
• pneumonitis.

Children and adolescents Side effects in children and adolescents occur with a similar frequency to those in adult patients. Drug-induced gum hyperplasia occurs more frequently in children and adolescents, as well as in patients who do not maintain proper oral hygiene.

Reporting side effects

If you experience any side effects, including any side effects not listed in this leaflet, you should tell your doctor or pharmacist. Side effects can be reported directly to the Department of Drug Safety Monitoring of the Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products Al. Jerozolimskie 181C 02-222 Warsaw Tel.: +48 22 49 21 301 Fax: +48 22 49 21 309 Website: https://smz.ezdrowie.gov.pl Side effects can also be reported to the marketing authorization holder. By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store Phenytoinum WZF

Store in the original packaging to protect from light. The medicine should be stored in a place that is out of sight and reach of children. Do not use this medicine after the expiry date stated on the carton and blister. The expiry date refers to the last day of the month. The inscription on the packaging after the abbreviation EXP means the expiry date, and after the abbreviation Lot/LOT, it means the batch number. Medicines should not be disposed of via wastewater or household waste. You should ask your pharmacist how to dispose of medicines that are no longer needed. This will help protect the environment.

6. Contents of the packaging and other information

What does Phenytoinum WZF contain

• The active substance of the medicine is phenytoin. Each tablet contains 100 mg of phenytoin.
• The other ingredients are: potato starch, povidone K-25, talc, magnesium stearate.

What Phenytoinum WZF looks like and what the packaging contains

Phenytoinum WZF is available in the form of white, round, flat tablets with a beveled edge and a single-sided engraving of the letter H. The packaging contains 60 tablets.

Marketing authorization holder

Polpharma S.A. Pharmaceutical Works ul. Pelplińska 19, 83-200 Starogard Gdański tel. +48 22 364 61 01

Manufacturer

Polpharma S.A. Pharmaceutical Works Production Plant in Nowa Dęba ul. Metalowca 2, 39-460 Nowa Dęba Date of last revision of the leaflet:December 2024