Diphenin
Difenin: instructions for use and reviews
- 1. Release form and composition
- 2. Pharmacological properties
- 3. Indications for use
- 4. Contraindications
- 5. Method of application and dosage
- 6. Side effects
- 7. Overdose
- 8. Special instructions
- 9. Drug interactions
- 10. Analogs
- 11. Terms and conditions of storage
- 12. Terms of dispensing from pharmacies
- 13. Reviews
- 14. Price in pharmacies
Latin name: Diphenine
ATX code: N03AB02
Active ingredient: phenytoin (phenytoin)
Producer: JSC "Lugansk KhFZ" (Ukraine), JSC "Usolye-Sibirskiy Khimfarmzavod" (Russia)
Description and photo update: 2019-16-08
Prices in pharmacies: from 27 rubles.
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Diphenin is a drug with an anticonvulsant effect.
Release form and composition
Difenin is produced in the form of tablets (in contoured non-cell packs of 10 pcs., 1 or 2 packs in a cardboard box).
The active ingredient is a part of 1 tablet: phenytoin - 100 mg.
Pharmacological properties
For Diphenin, anticonvulsant, antiarrhythmic, analgesic and muscle relaxant effects are characteristic.
Pharmacodynamics
When taking phenytoin, an anticonvulsant effect is observed, which is not accompanied by a pronounced hypnotic effect. The mechanism of the anticonvulsant activity that Diphenin exhibits is currently not fully understood. Presumably, the specific effect of phenytoin in epilepsy is carried out through inhibition of the excitability of neurons of the epileptic focus and the effect on neurotransmitters. The substance is a blocker of sodium channels, increases the time of their inactivation, prevents the generation and propagation of high-frequency discharges.
It is assumed that the antiarrhythmic effect of phenytoin is due to the normalization of the entry of calcium and sodium ions into the cells of Purkinje cardiac fibers. Diphenin suppresses abnormal automatism and reduces the duration of the action potential in the His-Purkinje system due to a decrease in the repolarization time, and also helps to shorten the effective refractory period.
Pharmacokinetics
Phenytoin is characterized by a first pass effect through the liver. Its bioavailability does not exceed 50%. The substance penetrates into breast milk, cerebrospinal fluid, bile, saliva, gastric and intestinal juice, semen and crosses the placental barrier. Its degree of binding to plasma proteins is quite significant (up to 90% or more). The maximum concentration of phenytoin in the blood serum is reached in about 1.5–3 hours. The therapeutic level of the drug in the blood serum is 10–20 μg / ml (40–80 μmol / L). The equilibrium concentration of the drug is usually established on the 5-10th day after the start of treatment when taking the average daily dose.
The serum phenytoin concentration that provides the desired therapeutic effect may be determined by the type of epileptic seizure. In some cases, it is possible to prevent epileptic seizures with a serum phenytoin concentration of 6-9 μg / ml (24-36 μmol / L). Therefore, it is recommended to monitor the effectiveness of therapy not by the content of the drug in the blood serum, but by the clinical symptoms of the disease.
Phenytoin is metabolized by hepatic enzymes to form inactive metabolites. The main inactive metabolite is 5- (p-hydroxyphenyl) -5-phenylhydantoin. The drug tends to accumulate in the body, which can lead to the development of unforeseen toxic reactions.
The half-life of phenytoin is 24 hours. From 35 to 60% of the dose taken is excreted in the urine, from 40 to 65% of the administered phenytoin - in the bile. The degree of excretion increases with an alkaline urine reaction.
Indications for use
- Epilepsy (large convulsive seizures), epileptic seizures in neurosurgery, status epilepticus with tonic-clonic seizures (treatment and prevention);
- Ventricular arrhythmias (including those associated with intoxication with glycosides or tricyclic antidepressants);
- Trigeminal neuralgia (as a second-line agent or concomitantly with carbamazepine).
Contraindications
- Sinus bradycardia;
- AV block II-III degree;
- Sinoatrial blockade;
- Morgagni-Adams-Stokes syndrome;
- Cachexia;
- Heart failure;
- Porphyria;
- Functional disorders of the kidneys and liver;
- Pregnancy (except in cases where the benefits to the mother are higher than the expected harm to the fetus) and lactation;
- Hypersensitivity to the components of Diphenin.
Instructions for the use of Diphenin: method and dosage
Diphenin is taken orally.
For adults, the drug is usually prescribed at an initial daily dose of 3-4 mg / kg. The dose is gradually increased until the optimal therapeutic effect is achieved. Typically, the maintenance dose is 200-500 mg per day in one or more doses.
Children are usually prescribed 5 mg / kg per day in 2 divided doses, followed by an increase in dose, but not more than 300 mg per day. The maintenance daily dose for children is 4-8 mg / kg.
Side effects
During therapy, it is possible to develop disorders on the part of some body systems, manifested with different frequencies:
- Digestive system: possibly - liver damage, nausea, constipation, vomiting, toxic hepatitis. During the first 6 months of treatment, hyperplasia may develop, starting with gingivitis (more common in patients under 23 years of age);
- Central and peripheral nervous system: possible - ataxia, nystagmus, mood changes, confusion, muscle weakness, dizziness, hand tremors, impaired coordination of movements, transient nervousness, sleep disturbances, stuttering or blurry speech; rarely - peripheral neuropathy;
- Endocrine system: possible - enlargement of facial features, including enlargement of the tip of the nose, thickening of the lips and extension of the lower jaw, hypertrichosis;
- Musculoskeletal system: possibly - Dupuytren's contracture; rarely - peripheral polyarthropathy. With prolonged therapy without adhering to a diet that satisfies the need for vitamin D or with a lack of sunlight, rickets and osteomalacia may occur;
- Hematopoietic system: rarely - megaloblastic anemia, thrombocytopenia, granulocytopenia, leukopenia, pancytopenia, agranulocytosis;
- Metabolism: possibly - impaired glucose uptake caused by inhibition of insulin release, the development of hypocalcemia and impaired vitamin D metabolism;
- Allergic reactions: rarely - skin rash, which may be a symptom of more severe skin reactions, eosinophilia, drug lymphadenopathy, fever;
- Others: rarely - Peyronie's disease.
Overdose
With an overdose of Diphenin, the manifestations of toxic side effects may be more pronounced. The specific antidote is unknown, therefore, it is recommended to take activated charcoal, laxatives and the appointment of symptomatic therapy.
With prolonged use, manifestations of the syndrome of hypersensitivity to phenytoin and pronounced depression of the central nervous system can be observed, which requires the abolition of Diphenin.
special instructions
In the presence of hypersensitivity to one of the hydantoin anticonvulsants, hypersensitivity to other drugs in this group is also possible.
Sudden cessation of the use of Diphenin in epileptic patients can lead to the development of a withdrawal syndrome. If it is necessary to abruptly discontinue therapy (for example, with the development of hypersensitivity reactions or allergic reactions), anticonvulsants that are not related to hydantoin derivatives should be used.
Phenytoin is extensively metabolized in the liver, therefore, patients with functional liver disorders, as well as elderly patients, need to adjust the dosage regimen.
During therapy, especially long-term, it is recommended to follow a diet that satisfies the need for vitamin D, you should also ensure exposure to UV radiation.
When using Diphenin in children during the growth period, the risk of developing disorders of the connective tissue increases.
The concentration of phenytoin in plasma may increase with acute alcohol intoxication; with chronic alcoholism - to decrease.
Influence on the ability to drive vehicles and complex mechanisms
According to the instructions, Difenin slows down the speed of psychomotor reactions, which must be taken into account when performing work that requires increased attention and quick psychomotor reactions, including driving.
Drug interactions
With the simultaneous use of Diphenin with some drugs, undesirable effects may occur:
- Medicines that have a depressing effect on the central nervous system: it is possible to increase the depressing effect on the central nervous system;
- Antifungal agents, clozapine, digitoxin, glucocorticosteroids, estrogens, dicumarol, furosemide, doxycycline, oral contraceptives, quinidine, rifampicin, vitamin D: their therapeutic effect may change;
- Amiodarone, antifungal agents (including fluconazole, amphotericin B, miconazole, ketoconazole, itraconazole), metronidazole, sulfonamides, histamine H1 receptor blockers, chlordiazepoxide, tolbutamide, chloramphenicol, salicylates, dicumaroxide, diazepheniate, isotophosphate, dicumaroxide, diazepheniate estrogens, succinimides, sulfinpyrazone, trazodone: an increase in the concentration of phenytoin in the blood plasma is possible, which can lead to an increase in its therapeutic effect and an increase in the risk of side effects;
- Acetazolamide: possible development of osteomalacia, rickets;
- Phenobarbital, phenothiazine derivatives (including chlorpromazine, prochlorperazine, thioridazine), antineoplastic agents: an increase or decrease in the concentration of phenytoin in the blood plasma is possible (the effect of Diphenin on the plasma concentration of phenobarbital is unpredictable);
- Valproic acid: during the first few weeks of therapy, the total concentration of phenytoin in blood plasma may decrease;
- Acyclovir: a decrease in the concentration of phenytoin in blood plasma and a decrease in its effectiveness is possible;
- Verapamil, nimodipine, felodipine: decrease in their concentration in blood plasma;
- Desipramine, pyridoxine at a dose of 200 mg: a decrease in its concentration in blood plasma is possible;
- Imipramine, clarithromycin, ritonavir, felbamate: an increase in the concentration of phenytoin in blood plasma is possible;
- Paracetamol: decrease in its effectiveness;
- Vigabatrin, carbamazepine, reserpine, folic acid, sucralfate: a decrease in the therapeutic effect of phenytoin and its concentration in blood plasma is possible;
- Theophylline: may decrease their plasma concentration and effectiveness;
- Sucralfate: decreased absorption of phenytoin;
- Phenylbutazone, cimetidine, disulfiram, diltiazem, nifedipine, gabapentin: an increase in the concentration of phenytoin in the blood plasma is possible with the subsequent development of toxic reactions;
- Folic acid: decreased effectiveness of phenytoin;
- Ciprofloxacin: a change in the concentration of phenytoin in the blood plasma is possible, the interaction of drugs is ambiguous.
Analogs
The analogues of Diphenin are: Difantoin, Solantil, Fengidon, Eptoin.
Terms and conditions of storage
Store in a dark, dry place out of reach of children at a temperature of 5-30 ° C.
Shelf life is 4 years.
Terms of dispensing from pharmacies
Dispensed by prescription.
Reviews about Diphenin
Almost all reviews about Diphenin that patients leave are positive. They report that even during long-term therapy, the effectiveness of the drug does not decrease, and it successfully prevents epileptic seizures, as well as shortens their duration.
Some patients note that when switching from Diphenin to other antiepileptic drugs, a deterioration in well-being is possible. Also, the antiepileptic effect of phenytoin is enhanced when it is included in the course of combination therapy.
The price of Diphenin in pharmacies
The approximate price of Difenin in pharmacy chains is about 32-36 rubles (for a pack of 10 tablets) or 62-74 rubles (for a pack of 20 tablets).
Difenin: prices in online pharmacies
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Drug name Price Pharmacy |
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Difenin 0.117 g tablets 10 pcs. RUB 27 Buy |
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Difenin 0.117 g tablets 20 pcs. RUB 65 Buy |
Maria Kulkes Medical journalist About the author
Education: First Moscow State Medical University named after I. M. Sechenov, specialty "General Medicine".
Information about the drug is generalized, provided for informational purposes only and does not replace the official instructions. Self-medication is hazardous to health!
