Neuralgin

Neuralgin is a drug from the subcategory of anticonvulsants.

Indications Neuralgina

It is used in adults to relieve high-intensity pain (also neuropathic).

In addition, it is used in combination with other anticonvulsants to eliminate partial epileptic seizures (accompanied by a secondary stage of generalization or not) - in adults and adolescents from 12 years of age. Along with this, it is prescribed for partial seizures - in children 6-12 years of age.

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Release form

The component is released in capsules, 100 pieces in a bottle or 10 pieces in a cell plate; there are 3 such plates in a pack.

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Pharmacodynamics

It has not yet been possible to determine the exact principle of action of gabapentin. The element is related to the neurotransmitter GABA in its structure, but in its type of influence it differs from other active components that interact with GABA synapses (among them are barbiturates with valproates, benzodiazepines and substances that slow down the activity of GABA transaminase and slow down the processes of GABA uptake, as well as GABA prodrugs and GABA agonists).

In vitro tests using radiolabeled gabapentin have described a new peptide-binding region within the rat brain, including the hippocampus and neocortex, that may be related to the analgesic and anticonvulsant effects of gabapentin and its structural derivatives. The site of gabapentin synthesis has been identified as the α2-δ subunit of voltage-sensitive Ca channels.

Gabapentin, which is at clinical levels, is not synthesized with other common neurotransmitter or therapeutic brain terminals, including GABA-A and GABA-B, as well as glutamate, benzodiazepine, glycine or N-methyl-d-aspartate terminals.

Gabapentin does not interact with Na channels in vitro, which distinguishes it from carbamazepine and phenytoin. The substance partially weakens the response to NMDA glutamate agonist activity in individual in vitro tests, but only at values above 100 μM, which cannot be obtained in vivo.

The drug slightly reduces the volumes of released monoamine neurotransmitters in vitro. Its use in rats causes an increase in GABA turnover in certain areas of the brain (an effect similar to that of sodium valproate, albeit in different areas of the brain). What significance this activity of gabapentin has for anticonvulsant activity remains to be determined.

In animals, the substance penetrates the brain without complications, preventing seizures caused by maximum electric shock or chemical convulsants (including elements that slow down the binding of GABA), as well as genetic models of seizures.

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Pharmacokinetics

After oral administration, gabapentin is rapidly absorbed in the gastrointestinal tract, without regard to food intake; in general, no interaction with food is observed. Plasma Cmax values are recorded after 2-3 hours. Portion size and plasma drug parameters are linearly dependent. Repeated administration of the drug does not change the pharmacokinetic characteristics. Absolute bioavailability values are approximately 59%, unchanged in case of course use.

Gabapentin does not undergo synthesis with intraplasmic blood protein. The substance passes through the hepatoencephalic barrier; in epileptics, its values in the cerebrospinal fluid are approximately 20% of the level of the corresponding equilibrium plasma parameters of the drug.

The drug is almost not subject to metabolic processes inside the human body, does not lead to slowing down or induction of liver enzymes. The drug prevents the metabolism of the most commonly used anticonvulsants.

Excretion in an unchanged state occurs only through the kidneys. The half-life is not tied to the portion size, on average equal to 5-7 hours in people with healthy renal secretory activity. The substance can be removed from blood plasma through hemodialysis.

Dosing and administration

The capsule can be taken without reference to food. To reduce the likelihood of negative symptoms, it is recommended to take the first portion before bedtime.

In case of pain of neuropathic genesis, 0.3 g of the medicine should be used once on the 1st day, 0.3 g twice on the 2nd day, and 0.3 g three times on the 3rd day. If necessary, the daily dosage is gradually increased until an analgesic effect is achieved (maximum – 1.8 g, which is divided into 3 doses). In severe stages of the disease, higher doses are used – 1.8-3.6 g per day.

In case of epilepsy, complex therapy is carried out. Persons over 12 years of age should first take 0.3 g of the drug 3 times a day. The most effective portions are considered to be in the range of 0.9-1.8 g per day (they must be divided into 3 uses). The substance should be used at maximum 12-hour intervals.

Children aged 6-12 years should use 25-35 mg/kg per day (the dosage is divided into 3 doses).

Use Neuralgina during pregnancy

Prescribing the drug to pregnant women is permitted only in situations where the benefit of its administration to the woman is considered more likely than the risk of developing negative effects on the fetus.

The active ingredient (gabapentin) is excreted in breast milk, which is why breastfeeding is not possible when using it.

Contraindications

Contraindicated for use in cases of severe intolerance associated with medicinal substances.

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Side effects Neuralgina

Side effects include:

• infectious diseases: viruses, urinary tract infections, pneumonia, and otitis media;
• lesions affecting the blood system: leukopenia or thrombocytopenia;
• immune disorders: allergies;
• metabolic disorders: changes in blood sugar levels, anorexia, increased appetite and weight gain or loss;
• mental disorders: depression, hallucinations, feelings of anxiety or agitation, thought disorder and emotional lability;
• lesions affecting the functioning of the nervous system: ataxia, amnesia, drowsiness, dysarthria and convulsions, as well as hyperkinesia, headaches, insomnia, dizziness and tremor. In addition, coordination disorder, nystagmus, hypokinesia with paresthesia and hypesthesia, as well as potentiation/decrease/disappearance of reflexes and other motor disorders (dystonia, athetosis or dyskinesia);
• problems with visual function: diplopia or amblyopia, as well as decreased visual acuity;
• hearing disorders: vertigo or tinnitus;
• cardiovascular disorders: palpitations, vasodilation and increased blood pressure;
• respiratory disorders: pharyngitis, runny nose, cough, dyspnea and bronchitis;
• digestive disorders: diarrhea, vomiting, constipation, gingivitis, abdominal pain, dental disease, dry mouth and flatulence, as well as hepatitis, jaundice, pancreatitis and increased liver function tests;
• epidermal lesions: itching, acne, SJS, Quincke's edema, bruises and rashes, as well as facial edema, erythema multiforme and alopecia;
• damage to the musculoskeletal system: arthralgia, pain in the back, muscle twitching and myalgia;
• urogenital disorders: urinary incontinence, renal failure, gynecomastia and impotence;
• other symptoms: severe fatigue, asthenia, swelling (sometimes peripheral), gait disturbance, and at the same time pain, fever, cold and feeling of malaise, chest pain and withdrawal syndrome (includes nausea, hyperhidrosis, insomnia and feeling of anxiety).

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Overdose

Signs of intoxication: feeling of drowsiness, frequent and loose stools, double vision, lethargy and slurred speech.

In such cases, the victim is prescribed sorbents. The drug can be excreted using hemodialysis sessions.

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Interactions with other drugs

The drug can be combined with other anticonvulsants (carbamazepine, phenobarbital, as well as valproic acid and phenytoin), oral contraception (containing ethinyl estradiol or norethindrone) and agents that block tubular secretion and reduce renal excretion of gabapentin.

Antacids that contain Al3+ and Mg2+ reduce the bioavailability of the drug by approximately 20%, which is why it is recommended to take it 2 hours after the administration of antacids.

When used in combination with myelotoxic drugs, potentiation of hematotoxicity (development of leukopenia) occurs.

When using morphine capsules with a controlled release dose of 60 mg over 2 hours together with gabapentin in a portion of 0.6 g, the mean AUC values of the latter increased by 44% compared with the AUC values of gabapentin used without morphine. Because of this, it is necessary to carefully monitor the condition of people, noting such a symptom of CNS depression as a feeling of drowsiness. In such a violation, it is necessary to reduce the dose of morphine or gabapentin accordingly.

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Storage conditions

Neuralgin must be stored at temperatures in the range of 15-30°C.

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Shelf life

Neuralgin can be used for a period of 5 years from the date of release of the therapeutic substance.

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Application for children

Neuralgin is used in the adjuvant treatment of partial seizures with secondary generalization (or not) in children over 6 years of age.

The medication can be prescribed for monotherapy for the above-mentioned disorders in children over 12 years of age.

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Analogues

Analogues of the drug are the drugs Gabagamma, Gabantin with Gabastadin, Nupintin with Gabalept, Tebantin with Gatonin, and also Gabamax and Meditan with Gabapentin. In addition to that, Gabata, Convalis with Grimodin and Epigan with Neuropentin.