Index of drugs

Status epilepticus or repetitive seizures at short intervals. Prevention of convulsions after neurosurgical procedures and / or head injuries. acute cardiac arrhythmias, in the course of poisoning with digitalis glycosides, after myocardial infarction, under general anesthesia, cardiac surgery, during cardiac catheterization and electric defibrillation.

1 ampoule of 5 ml contains 250 mg phenytoin.

Hydantoin derivative with anticonvulsant effect. It stabilizes the cell membrane, affects the transport of sodium, Calcium and potassium ions. It inhibits the spread of cortical discharges, thus preventing the generalization of seizure; increases the seizure threshold. It lowers the tonic phase, but does not affect the clonic phase of seizures. In therapeutic doses, it does not have sedative properties, but it works anti-arrhythmically. After intravenous administration, it starts to work after about 20 min; T_0,5 is 10-15 h. Plasma proteins are 40-45% bound. Metabolized in the liver, excreted in the urine and faeces in the form of metabolites.

Hypersensitivity to the components of the drug or other hydantoins. Sinus bradycardia, sinoatrial block, atrio-ventricular block IIst. and third century, the Adams-Stokes team. Co-administration with delavirdine (due to the possibility of loss of virological response and delavirdine resistance or non-reverse transcriptase inhibitors). Due to the high pH of the solution, do not administer the drug to the artery.

In adults, the administration rate should not exceed 50 mg / min, in neonates 1-3 mg / kg / min. Carefully use in elderly or severely ill people - more often are exposed to serious complications associated with too rapid administration of the product or too much of it. Special care should be taken in patients during the first 3 months after myocardial infarction and in patients with reduced cardiac output (left ventricular ejection volume below 35%). Caution in patients with hypotension. Use with caution in patients with severe damage to blood cells and bone marrow. Patients taking anticonvulsants, including phenytoin, have reported hypersensitivity syndrome (HSS) or drug eruption with eosinophilia and potentially fatal (DRESS) potentially life-threatening symptoms. Initial symptoms may resemble acute viral infection and usually occur 2-4 weeks after the first exposure. Patients with an increased risk of developing HSS / DRESS are black people in whom this syndrome has previously occurred or occurred in their family, as well as immunocompromised patients. Phenytoin may cause rare but life-threatening side effects on the skin (exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis). In such cases, the drug should be discontinued and never administered again. If the rash is milder (morbid or flat-like), treatment can be repeated after complete rash. Fanytoin is not effective in the treatment of seizures of the unconscious (petit mal). If there are simultaneously tonic-clonic seizures (grand mal type) and seizures of the unconscious (petit mal), it is necessary to use combination therapy. Patients with hepatic impairment may need to reduce the maintenance dose to prevent accumulation and toxicity. Phenytoin is not indicated for the treatment of seizures caused by hypoglycaemia or other metabolic disorders (may affect Glucose metabolism and inhibit insulin release). Caution is advised when treating patients with diabetes. It may increase the symptoms of people who have porphyria. The product contains ethanol - carefully used in people with alcoholism. The ethanol content should also be taken into account when using the drug in pregnant and breastfeeding women, in children and in patients with liver disease. Patients should be monitored for signs of suicidal ideation and behavior.

Both genetic factors and epilepsy may lead to fetal malformations to a greater extent than drug therapy. Most pregnant women using anticonvulsant drugs give birth to healthy children. In the case of patients with severe epileptic seizures, the drug should not be discontinued because there is a high likelihood of an epileptic state accompanied by hypoxia which is life-threatening. In individual cases, phenytoin may be discontinued in a woman with epilepsy before pregnancy or during pregnancy, but after analyzing whether discontinuation of phenytoin (and therefore possible seizures) does not pose a greater risk to the embryo and fetus compared to the action of the drug. Anticonvulsants, including phenytoin, may cause developmental defects in offspring in a small number of patients with epilepsy (eg cleft lip / palate, malformations of the heart) - the role of the drug in such cases is not explained. Phenytoin may be used during pregnancy, especially at the beginning, only in cases where, according to the doctor's assessment, the benefit for the mother outweighs the potential risk to the fetus. In addition, in children whose mothers received phenytoin and other anti-epileptic medicines, fetal hydantoin syndrome was reported more frequently (weight deficiency, microcephaly, mental retardation). These features are often associated with intrauterine inhibition of fetal development for other reasons. In children whose mothers were given phenytoin during pregnancy, isolated cases of malignant tumors, including neuroblastoma, have been reported. An increase in the incidence of seizures during pregnancy was observed, which may be due to a disturbance in the absorption or metabolism of phenytoin - it is recommended to periodically determine the concentration of phenytoin in the serum to adjust the dosage to the patient's condition. After delivery, consideration should be given to returning to the dosage recommended prior to pregnancy. There have been reports of blood coagulation disorders in newborns whose mothers took phenytoin. An effective preventive and curative measure is to administer vitamin K to a woman before delivery and a newborn baby at birth. Phenytoin is excreted in breast milk in small amounts - it is not recommended during breastfeeding.

Nervous system disorders: nystagmus, disorder of movement, blurred speech, disturbed coordination, confusion, paresthesia, lethargy, dizziness (vertigo), insomnia, transient nervousness, muscle tremors, headaches, drowsiness, rare cases of dyskinesia, including chorea, dystonia trembling and coarse fluttering of the hands; Peripheral sensory polyneuropathy (mainly in patients who take phenytoin for a long time), tonic seizures, taste disturbances. Cardiac disorders: hypotension, severe cardiotoxic reactions and deaths with atrial and ventral conduction depression and ventricular fibrillation (severe complications are most common in elderly or debilitated patients). Respiratory, thoracic and mediastinal disorders: impaired respiratory function including respiratory arrest; pneumonia. General disorders and administration site conditions: hypersensitivity reactions, anaphylactoid reactions, anaphylaxis, local irritation, inflammation and tenderness, necrosis and separation of necrotic tissue from healthy tissue after subcutaneous or perivascular injection; swelling, discoloration and pain occurring distally from the injection site. Skin and subcutaneous tissue disorders: dermatological symptoms, which are sometimes accompanied by a fever, include scaried-like or odorous rash; other types of dermatitis are less common; bullous exfoliative or purpura dermatitis, lupus erythematosus, very rare Stevens-Johnson syndrome, toxic epidermal necrolysis. Blood and lymphatic system disorders: thrombocytopenia, leukopenia, granulocytopenia, agranulocytosis, aplastic anemia with and without bone marrow function, macrocytosis, megaloblastic anemia, lymphadenopathy (local or generalized), including benign hypertrophy, alleged lymphoma, Hodgkin's disease. Gastrointestinal disorders: acute liver failure, hepatotoxicity, liver damage, vomiting, nausea, constipation.Musculoskeletal and connective tissue disorders: facial features, lips enlargement, gum hypertrophy, hypertrichosis, polyarthritis, rare Peyronie's disease and Dupuytren's contracture; reduction of bone mineral density, osteopenia, osteoporosis and fractures in patients with long-term therapy. Immune system disorders: hypersensitivity / drug eradication syndrome with eosinophilia and general symptoms (HSS / DRESS) in rare cases leading to death; systemic lupus erythematosus, periarteritis nodosa and immunoglobulin disorders. Renal and urinary disorders: interstitial nephritis. Laboratory tests: phenytoin may cause a small decrease in serum free thyroxine concentrations (without affecting the results of hypothyroidism tests). It may cause a decrease in protein-bound Iodine, a decrease in Dexamethasone or methoprone, an increase in serum Glucose, alkaline phalphatase, γ-glutamyl transpeptidase, and a decrease in calcium and folic acid. It can affect the results of the test for diabetes.

Intravenously. It is necessary to monitor the ECG, blood pressure, aurologic status and regularly check the patient's phenytoin level. Observe the symptoms of respiratory depression. The parenteral bolus of phenytoin should be administered at a rate not exceeding 50 mg / min in adults, a large vein, a high-caliber needle or an intravenous catheter. For infusion, the drug should be diluted in 50-100 ml of physiological saline solution, with the final concentration of phenytoin in a solution not exceeding 10 mg / ml. Due to the slow rate of phenytoin administration, other procedures will usually be required for rapid seizure control, including simultaneous intravenous administration of benzodiazepine or intravenous short-acting barbiturate.Status epilepticus or repetitive seizures at short intervals. Adults and adolescents from 13 years: the initial dose of 230 mg of phenytoin intravenously at a maximum speed of 0.5 ml / min. If the convulsions did not subside after 20-30 minutes. the dose can be repeated. After the convulsions have resolved, 230 mg of phenytoin can be administered intravenously every 1.5-6 h. To achieve rapid saturation with the drug, a maximum daily dose of 17 mg / kg can be given. Children up to 12 years: On the first day the maximum daily dose is 30 mg / kg, on the second day 20 mg / kg, in the third day 10 mg / kg. The maximum infusion rate is 1 mg / kg. for a minute.Prevention of convulsions after neurosurgical procedures and / or head injuries. Adults and adolescents from 13 years: 1-2 ampoules, ie 230-460 mg of phenytoin daily into a vein with a maximum speed of 0.5 ml / min. Children under 12: 5-6 mg / kg with an injection rate reduced according to the body weight and age of the child.Acute cardiac arrhythmias (only in situations requiring urgent help): a dose of 3.5-5 mg / kg intravenously at a rate of 30-50 mg / min. If necessary, the dose can be repeated. A total daily dose of 700-1000 mg is usually sufficient. The duration of therapy depends on the underlying disease and its course. It is unlimited, provided the drug is well tolerated.