Phenytoin Sodium Tablets

This product is an anti-epileptic drug and anti-arrhythmic drug. The therapeutic dose does not cause sedation and hypnosis. 1 Animal experiments have shown that this product has a selective antagonistic effect on the tonic phase of super-strong electric shock and convulsion, but is ineffective or even aggravates the spasm phase. Therefore, it is effective for grand mal epilepsy, but ineffective for absence seizures. Its anti-epileptic mechanism has not yet been elucidated. It is generally believed that it increases the outflow of sodium ions from cells and reduces the inflow of sodium ions, thereby stabilizing the nerve cell membrane, increasing the excitation threshold, and reducing the spread of high-frequency discharges of the lesion. 2 In addition, this product shortens the action potential interval and the effective refractory period, and can also inhibit the influx of calcium ions, reduce myocardial autonomy, inhibit the sympathetic center, and have an inhibitory effect on the ectopic rhythm points of the atrium and ventricle, and increase the threshold of atrial fibrillation and ventricular fibrillation. 3 Its stabilizing cell membrane and reducing synaptic transmission have anti-neuralgia and skeletal muscle relaxation effects. 4 This product can inhibit the synthesis (or) secretion of collagenase by skin fibroblasts. It can also accelerate the metabolism of vitamin D, cause lymphadenopathy, have anti-folate effects, have inhibitory effects on the hematopoietic system, cause allergic reactions, have enzyme-inducing effects, and intravenous administration can dilate peripheral blood vessels.

The main ingredient of this product is phenytoin sodium, its chemical name is: 5,5-diphenyl-2,4-imidazolidinedione sodium salt, chemical structure formula is: Molecular formula: C15H11N2NaO2 Molecular weight: 274.25

This product is white tablets or film-coated tablets.

It is suitable for the treatment of generalized tonic-clonic seizures, complex partial seizures (psychomotor seizures, temporal lobe epilepsy), simple partial seizures (localized seizures) and status epilepticus. It can also be used to treat trigeminal neuralgia, recessive dystrophic epidermolysis bullosa, paroxysmal choreoathetosis, paroxysmal control disorders (including behavioral disorders such as anger, anxiety and insomnia due to excessive excitement), myotonia and cardiac conduction disorders in case of overdose of tricyclic antidepressants. This product is also suitable for ventricular and supraventricular arrhythmias caused by digitalis poisoning, and has poor efficacy on arrhythmias caused by various other reasons.

1 Anti-epileptic. Common dosage for adults: 250-300 mg per day, 100 mg at the beginning, twice a day, increase to 250-300 mg within 1-3 weeks, divided into three times for oral administration, the maximum dose is 300 mg once, 500 mg per day. Due to individual differences and saturated pharmacokinetic characteristics, medication needs to be individualized. After the application achieves control of seizures and the blood drug concentration reaches a steady state, a long-acting (controlled release) preparation can be used instead, which is taken once. If the seizures are frequent, 12-15 mg/kg can be taken in 2-3 times, once every 6 hours, and 100 mg (or 1.5-2 mg/kg according to body weight) can be given on the second day, 3 times a day until the appropriate dose is adjusted. Common dosage for children: 5 mg/kg per day, divided into 2-3 times, adjusted as needed, and not more than 250 mg per day. The maintenance dose is 4-8 mg/kg or 250 mg/m2 per body surface area, divided into 2-3 times, and blood drug concentration monitoring can be performed if conditions permit. 2 Antiarrhythmic. Commonly used in adults: 100-300 mg, taken once or divided into 2-3 times, or 10-15 mg/kg on the first day, 7.5-10 mg/kg on the second to fourth day, and maintenance dose of 2-6 mg/kg. Common dosage for children: Start with 5 mg/kg of body weight, orally in 2-3 times, and adjust the daily dose to no more than 300 mg according to the condition, and the maintenance dose is 4-8 mg/kg, or 250 mg/m2 of body surface area, orally in 2-3 times. 3 Collagenase synthesis inhibitor. Commonly used dosage for adults starts with 2-3 mg/kg daily, divided into 2 times, and within 2-3 weeks, increase to the dosage that the patient can tolerate, and the blood drug concentration reaches at least 8 μg/ml. Generally 100-300 mg per day.

This product has few side effects, and gingival hyperplasia is common. The incidence rate is high in children, so oral hygiene and gingival massage should be strengthened. After long-term use or when the blood concentration reaches 30mu;g/ml, it may cause nausea, vomiting and even gastritis, which can be alleviated by taking it after meals. Adverse reactions of the nervous system are related to the dose, and dizziness and headache are common. In severe cases, it can cause nystagmus, ataxia, slurred speech and confusion, which can disappear by adjusting the dose or stopping the drug; less common adverse reactions of the nervous system include dizziness, insomnia, transient nervousness, convulsions, chorea, dystonia, tremor, flapping tremor, etc. It can affect the hematopoietic system, causing granulocytopenia and thrombocytopenia, and rare aplastic anemia; megaloblastic anemia is common, which can be prevented and treated with folic acid and vitamin B12. It can cause allergic reactions, common rash with high fever, and rare severe skin reactions.

Contraindications: Patients with a history of allergy to hydantoins or those with heart function impairment such as Ass syndrome, II-III degree atrioventricular block, sinus node block, sinus bradycardia, etc.

Precautions for children: Since the distribution volume and elimination half-life of children change with age, blood drug concentration should be measured frequently. The pharmacokinetics of this product are special for neonates or infants, and it is difficult to clinically assess the symptoms of poisoning, so it is generally not used first. Preschool children have strong liver metabolism, and blood drug concentration needs to be monitored multiple times to determine the frequency and dosage of medication. Precautions for pregnancy and lactation: This product can pass through the placenta and may cause teratogenesis, but it is believed that the risk of teratogenesis due to poor control of epileptic seizures is greater than the risk of medication, and the pros and cons should be weighed. Patients who can control seizures with this product should continue to take it during pregnancy and maintain effective blood concentration, and then readjust after delivery. Vitamin K should be supplemented one month before delivery, and vitamin K should be injected into the newborn immediately after delivery to reduce the risk of bleeding. This product can be secreted into breast milk, and mothers taking phenytoin are generally advised to avoid breastfeeding. Precautions for the elderly: The incidence of chronic hypoproteinemia in the elderly is high, and there are many combined medications for treatment. The interactions between drugs are complex. Caution should be exercised when using this product, the dosage should be low, and blood drug concentrations should be monitored frequently.

① Long-term use of acetaminophen in patients may increase the risk of liver poisoning and reduce the efficacy of this product; ② It is a liver enzyme inducer. When used in combination with corticosteroids, digitalis (including digoxin), oral contraceptives, cyclosporine, estrogen, levodopa, quinidine, oxytetracycline or tricyclic antidepressants, the effects of these drugs may be reduced; ③ Long-term drinking can reduce the concentration and efficacy of this product, but drinking a lot of alcohol while taking the medicine can increase the blood concentration; combined with chloramphenicol, isoniazid, phenylbutazone, and sulfonamides may reduce the metabolism of this product and increase the blood concentration, increasing the toxicity of this product; when used in combination with anticoagulants, the anticoagulant effect is initially increased, but it is reduced with continuous use; ④ When used in combination with drugs containing magnesium, aluminum or calcium carbonate, the bioavailability of this product may be reduced, and the two should be taken 2 to 3 hours apart; ⑤ When used in combination with hypoglycemic drugs or insulin, because this product can increase blood sugar, the dosage of the latter two needs to be adjusted; ⑥ In principle, patients using dopamine should not use this product; ⑦ When this product is used in combination with lidocaine or propranolol, it may enhance the inhibitory effect on the heart; ⑧ Although this product consumes folic acid in the body, increasing folic acid can reduce the concentration and effect of this product; ⑨ The effects of phenobarbital or primidone on this product vary greatly, and blood drug concentrations should be monitored frequently; when used in combination with valproic acid, there is a protein binding competition, and blood drug concentrations should be monitored frequently to adjust the dosage of this product. ⑩ When used in combination with carbamazepine, the latter has a lower blood concentration. If a large amount of antipsychotics or tricyclic antidepressants are used in combination, epileptic seizures may occur, and the dosage of this product needs to be adjusted.

Keep sealed.

50mg

24 months

Shanxi C&Y Pharmaceutical Group Co., Ltd.

• Founded in:

  2005-03-23

• Address:

  Area A, No. 1378 Heng'an Street, Datong Economic and Technological Development Zone, Shanxi Province

• Tax NO.:

  91140200770127753X

• Registered Funds:

  248.318563 yuan

• Website:

  Log in to view

• Email:

  Log in to view