Diphenine

Diphenytoin, also known by its generic name Phenytoin, is a drug widely used in neurology to treat and prevent certain types of seizures and epilepsy. Phenytoin belongs to a class of medications known as anticonvulsants or antiepileptic drugs.

Phenytoin stabilizes the threshold activity of neurons in the brain, limiting the excessive spread of nerve signals that can lead to seizures. It works by slowing down sodium channels in nerve cells, which helps reduce the activity in the brain needed to trigger a seizure episode.

Indications Diphenine

1. Epilepsy: Diphenin is commonly used to prevent various types of seizures, including generalized tonic-clonic seizures, partial seizures, and other forms of epilepsy.
2. Migraines: In some cases, Diphenin may be used as a preventative measure to reduce the frequency and severity of migraines.
3. Heart arrhythmias: Phenytoin is sometimes used to treat certain types of heart arrhythmias.
4. Tremor: Diphenin can be used to reduce tremor in patients with various neurological diseases, such as Parkinson's disease.
5. Trigeminal neuralgia: In rare cases, Diphenin may be prescribed to treat trigeminal neuralgia, although this is not the most common use.

Release form

1. Tablets: Diphenin is usually available as tablets for oral administration. Tablets may have different dosages depending on the specific medical purpose.
2. Solution: Sometimes Diphenin may be supplied as a solution for oral administration. The solution may be used in cases where tablets cannot be swallowed or when a more precise dosage is required.
3. Injection solution: Diphenin can also be presented as an injection solution, which is used to quickly introduce the drug into the body. This type of release form is usually used in situations where a rapid onset of action is needed or when it is impossible to take the drug orally.

Pharmacodynamics

1. Blocking native sodium channels: Phenytoin blocks the regeneration of native sodium channels, which prevents re-excitation of neurons and reduces their excitability.
2. Decreased neuronal excitability: This mechanism of action prevents the occurrence and spread of epileptic discharges in the brain.
3. Prevention of epileptic seizures: Phenytoin is used as a prophylactic agent to prevent the development of various types of epileptic seizures, including partial and generalized.
4. Antiarrhythmic effect: In addition to its antiepileptic effect, phenytoin may also have an antiarrhythmic effect by inhibiting the activity of cardiac sodium channels.
5. Additional effects: In some cases, phenytoin may also exhibit its anxiolytic and muscle relaxant properties, which may be useful in the treatment of certain other conditions, such as anxiety disorders and spasticity.

Pharmacokinetics

1. Absorption: Phenytoin can be administered either orally or intravenously. When taken orally, phenytoin is absorbed in the upper gastrointestinal tract, primarily in the duodenum. The rate and extent of absorption may vary depending on the drug and the individual patient.
2. Distribution: Phenytoin is highly bound to plasma proteins, primarily albumin. This factor may influence the tissue distribution of phenytoin and its pharmacological activity.
3. Metabolism: Phenytoin is metabolized in the liver, where the major metabolites are hydroxylated phenytoin (5-(4-hydroxyphenyl)-5-phenylhydantoin) and phenytoinic acid. Phenytoin metabolism can occur via several routes, including hydroxylation, glucuronidation, and oxidation of the aromatic ring.
4. Elimination: Phenytoin is eliminated primarily via the kidneys. In patients with normal renal function, the elimination half-life of phenytoin is approximately 22 hours, but may be increased in patients with renal impairment.

Dosing and administration

1. Directions for use:

   • Tablets: Tablets are usually taken orally, that is, by mouth. They should be swallowed whole with water. Do not break, chew, or crush the tablets unless instructed to do so.
   • Solution: Diphenin solution can be taken orally. The dosage should be measured using the enclosed dropper or measuring cup.
   • Injection solution: Diphenin injection solution is administered intravenously by medical personnel.

2. Dosage:

   • The dosage of Diphenin can vary greatly depending on the patient's specific medical condition.
   • The dosage is usually started low and gradually increased under the supervision of a physician until the optimal therapeutic effect is achieved.
   • The usual starting dose for adults is 100 mg 2-3 times a day. However, this may vary depending on the patient's response to the drug and the nature of the disease.
   • Children may be given a lower dose depending on their age and weight.

Use Diphenine during pregnancy

Using phenytoin (Diphenin) during pregnancy is associated with certain risks and potential complications. Here are some important findings from the studies:

1. Teratogenic effects: Phenytoin is classified as a potential teratogen, especially when taken early in pregnancy. Studies show an increased risk of birth defects such as cleft lip and/or palate, cardiac defects, and minor anomalies in newborns (Monson et al., 1973).
2. Fetal hydantoin syndrome: Children exposed to phenytoin in utero may exhibit features of fetal hydantoin syndrome, which includes craniofacial anomalies, microcephaly, mental retardation, and other physical and developmental abnormalities (Gladstone et al., 1992).
3. Immunologic reactions: Phenytoin may also cause immunologic reactions, including allergic reactions, which may potentially be worse during pregnancy (Silverman et al., 1988).

Because of these risks, the use of phenytoin during pregnancy requires careful medical supervision. Doctors generally recommend carefully weighing the potential risks and benefits of this medication, especially if it is used to control epilepsy, where the risk of seizures may also harm mother and baby.

Contraindications

1. Hypersensitivity: People with known hypersensitivity to phenytoin or other components of the drug should not use Diphenin.
2. Porphyria: Diphenin is contraindicated in the presence of porphyria, a rare inherited metabolic disorder that may be aggravated by phenytoin.
3. Atrioventricular block: Patients with atrioventricular block (impaired conduction of electrical impulses in the heart) should avoid using Diphenin, as it may enhance this effect.
4. Wolff-Parkinson-White syndrome: In patients with Wolff-Parkinson-White syndrome (an atrial syndrome that can lead to a fast heart rate), the use of Diphenin should be avoided.
5. Liver failure: Patients with liver failure should use Diphenin with caution, as it is metabolized in the liver. Dosage adjustments may be required depending on the degree of liver damage.
6. Pregnancy and breastfeeding: Diphenin may be contraindicated for use during pregnancy and breastfeeding. The doctor should evaluate the potential risks and benefits of its use in each specific case.
7. Other Medical Conditions: People with other serious medical conditions such as cardiac arrhythmias, blood disorders, mental disorders, etc. should discuss the use of Diphenin with their doctor before starting treatment.

Side effects Diphenine

1. Drowsiness and dizziness: These are some of the most common side effects of phenytoin. They can affect your ability to drive and perform other tasks that require concentration.
2. Incoordination: Patients may experience clumsiness or difficulty coordinating movements.
3. Malaise: Some people may experience a feeling of fatigue or general malaise.
4. Memory impairment: Diphenin may affect short-term and long-term memory.
5. Increased blood pressure: Some patients may experience increased blood pressure.
6. Hair loss: In some people, phenytoin may cause hair loss.
7. Digestive disorders: Stomach upset, nausea, vomiting, or changes in appetite may occur.
8. Allergic reactions: In rare cases, allergic reactions such as hives, itching or swelling may occur.
9. Decreased white blood cell count: Diphenin may decrease the number of white blood cells, making the body more vulnerable to infections.
10. Osteopenia: Long-term use of phenytoin may lead to osteopenia, or decreased bone density.

Overdose

1. Cardiac disorders: Include arrhythmia, tachycardia, and even heart failure.
2. Central nervous system: Drowsiness, depression, convulsions, decreased consciousness and coma may occur.
3. Respiratory failure: Respiratory depression or respiratory arrest may develop.
4. Gastrointestinal disorders: Nausea, vomiting, diarrhea and other gastrointestinal disorders may occur.
5. Metabolic disturbances: Changes in electrolyte levels (eg, hypernatremia), metabolic acidosis, or alkali imbalance may occur.
6. Other complications: Include allergic reactions, skin rashes, fever and other unusual reactions.

Interactions with other drugs

1. Pharmacokinetic interactions: Phenytoin may affect the metabolism and concentration of other drugs by inducing cytochrome P450 enzymes in the liver. This may lead to accelerated metabolism of other drugs and a decrease in their effectiveness. Such drugs include warfarin, carbamazepine, lamotrigine, digoxin, etc.
2. Pharmacodynamic interactions: Phenytoin may enhance or weaken the effects of other drugs, such as central depressants (e.g. alcohol, sedatives, antidepressants) or drugs that depress the central nervous system.
3. Plasma interactions: Phenytoin may compete with other drugs for binding to plasma proteins, which may lead to an increase in the free fraction of the other drug in plasma and an increase in its effect.
4. Electrolyte interactions: Phenytoin may cause hyperglycemia and hypomagnesemia, which may also interfere with the action of other drugs, especially those that affect glucose and magnesium levels in the body.