Description of the active substance:
This information is a reference and it is not enough that the drug has been prescribed by a doctor ..
PHARMACHOLOGIC EFFECT
Antiepileptic agent, a derivative of pyrrolidone (S-enantiomer of О±-ethyl-2-oxo-1-pyrrolidine-acetamide). The chemical structure differs from the known antiepileptic drugs. The mechanism of action of levetiracetam is not fully understood, but it is clear that it differs from the mechanism of action of known antiepileptic drugs.
In vitro studies have shown that levetiracetam affects the intra-neuronal concentration of Ca 2+ ions , partially inhibiting the current of Ca 2+ through N-type channels and decreasing the release of calcium from intra-neuronal depots. In addition, levetiracetam partially restores the currents through GABA- and glycine-dependent channels, reduced by zinc and ОІ-carbolines.
One of the proposed mechanisms is based on proven binding to the glycoprotein of the synaptic SV2A vesicles contained in the gray matter of the brain and spinal cord. It is believed that the anticonvulsant effect is realized in this way, which is expressed in counteracting the hypersynchronization of neuronal activity. Does not change the normal neurotransmission, but suppresses the epileptiform neuronal outbreaks induced by the GABA agonist bicuculine, and the excitation of glutamate receptors. The activity of levetiracitam has been confirmed with respect to both focal and generalized epileptic seizures (epileptiform manifestations / photoparoxysmal reaction).
PHARMACOKINETICS
After oral administration, levetiracetam is well absorbed from the digestive tract. Absorption is complete and linear, so the concentration in the blood plasma can be predicted based on the applied dose of the drug in mg / kg body weight. The degree of absorption is independent of the dose and time of ingestion. Bioavailability is about 100%.
After taking a dose of 1 g of C max in blood plasma is achieved after 1.3 hours and is 31 Ојg / ml, after repeated intake (2 times / day) - 43 Ојg / ml.
The binding to plasma proteins of levetiracetam and its main metabolite is less than 10%. V d of levetiracetam is about 0.5-0.7 l / kg. The equilibrium state is reached after 2 days with 2 times / day intake.
The formation of the primary pharmacologically inactive metabolite occurs without the participation of cytochrome P450 isoenzymes in the liver. Levetiracetam does not affect the enzymatic activity of hepatocytes.
In adults, T 1/2 of plasma is 7 В± 1 h and does not vary with dose, route of administration, or repeated administration. The average clearance is 0.96 ml / min / kg. 95% of the dose is excreted by the kidneys. The renal clearance of levetiracetam and its inactive metabolite is 0.6 ml / min / kg and 4.2 ml / min / kg, respectively.
In elderly patients, T 1/2 increases by 40% and is 10-11 hours, which is associated with a decrease in kidney function in this category of patients. In patients with impaired renal function, the clearance of levetiracetam and its primary metabolite correlates with QC. In the terminal stage of renal failure in adult patients, T 1/2 is 25 hours between dialysis sessions and 3.1 hours during dialysis. During a 4-hour dialysis session, up to 51% of levetiracetam is removed.
In the course of 4-hour dialysis, 51% of levetiracetam is removed from the body.
In patients with mild and moderate violations of liver function, significant changes in the clearance of levetiracetam do not occur. In severe violations of liver function with concomitant renal failure, the clearance of levetiracetam decreases by more than 50%.
The pharmacokinetics of levetiracetam in children is linear in the dose range from 20 to 60 mg / kg / day. C max is achieved in 0.5-1 hour. T 1/2 in children after a single oral intake at a dose of 20 mg / kg body weight is 5-6 hours. The total clearance of levetiracetam in children is approximately 40% higher than in adults and is in direct dependence on body weight.
INDICATIONS
As a monotherapy for the treatment of partial seizures with secondary generalization or without it in patients with 16 years of age with a newly diagnosed epilepsy.
As an auxiliary therapy: partial seizures with secondary generalization or without it in patients with epilepsy from the age of 4 (for intravenous administration) or from 6 years (for oral administration); myoclonic seizures in patients with juvenile myoclonic epilepsy from age 12; primary generalized tonic-clonic convulsions in patients with idiopathic generalized epilepsy in adults and adolescents over 12 years of age.
DOSING MODE
For oral or intravenous administration in the form of infusions.
Depending on the indications and age of the patient, a single dose of 250-750 mg. Multiplicity of application - 2 times / day.
The transition from oral to intravenous administration and back can be carried out with preservation of the dose and the frequency of administration.
With renal failure, dose adjustment is required. Patients with impaired liver function of mild to moderate severity do not need to adjust the dosage regimen. In patients with severe hepatic dysfunction, the value of QC may not reflect the true extent of renal dysfunction, therefore, at a CC <50 mL / min, a daily dose reduction of 50% is recommended.
In children, levetiracetam should be used in the appropriate dosage form.
SIDE EFFECT
On the part of the hematopoiesis system: infrequently - thrombocytopenia, leukopenia; rarely - neutropenia, pancytopaemia.
From the side of metabolism: often - anorexia; infrequently - increase / decrease in body weight.
From the side of the central nervous system: very often - drowsiness, headache; often - mood swings, emotional lability, depression, aggressiveness, insomnia, nervousness; infrequent behavior disorder, anger, anxiety, hallucinations, psychotic disorders, memory impairment, suicidal attempt. obsessive ideas, amnesia, frustration of tactile sensitivity, dizziness, headache, hyperkinesia, tremor, imbalance, absent-mindedness, paresthesia; rarely - personality disorder, incl. violation of thinking, suicide, hyperkinesis, choreoathetosis.
From the senses: often - dizziness; infrequently - diplopia, blurred vision.
From the respiratory system: often - cough.
From the digestive system: often - nausea, vomiting, diarrhea, abdominal pain, indigestion; infrequently - deviations of laboratory parameters of liver function from the norm; rarely - pancreatitis, hepatitis, liver failure.
From the skin and subcutaneous tissues: often - skin rash; infrequently - eczema, itchy skin; rarely - alopecia (in some cases, after the removal of levetiracetam), toxic epidermal necrolysis, erythema multiforme, Stevens-Johnson syndrome.
From the musculoskeletal system: infrequently - myalgia, muscle weakness.
Other: often - general weakness, fatigue; infrequently - nasopharyngitis, accidental traumatization.
Children most often: vomiting, agitation, mood swings, aggression, emotional lability, behavioral disorder, lethargy.
CONTRAINDICATIONS
Children under 4 years (for infusions), children under 6 years (for oral administration) hypersensitivity to levetiracetam, hypersensitivity to other pyrrolidone derivatives.
PREGNANCY AND LACTATION
Adequate and strictly controlled clinical trials on the safety of levetiracetam in pregnant women have not been conducted, therefore, levetiracetam should not be used during pregnancy, except in cases of extreme necessity.
Physiological changes in the body of a woman during pregnancy can affect the plasma concentration of levetiracetam, as well as other antiepileptic drugs. In pregnancy, decreased concentration of levetiracetam in plasma. This decrease is more pronounced in the I trimester (up to 60% of the baseline concentration in the period preceding the pregnancy).
Treatment with levetiracetam pregnant women should be carried out under special supervision. It should be borne in mind that interruptions in antiepileptic therapy may lead to a worsening of the course of the disease, which is harmful for both the mother and the fetus.
Levetiracetam is excreted in breast milk, so breastfeeding during treatment is not recommended. However, if treatment with levetiracetam is necessary during lactation, the risk / benefit ratio of treatment should be carefully weighed against the importance of breastfeeding.
SPECIAL INSTRUCTIONS
With caution should be used in elderly patients (over 65 years), with liver disease in the stage of decompensation, kidney failure.
Concomitant antiepileptic drugs (during the transfer of patients to receive levetiracetam) should be gradually phased out.
Patients with kidney disease and decompensated liver disease are recommended to study the function of the kidneys before treatment. Due to reports of cases of suicide, suicidal intentions and suicide attempts in the treatment with levetiracetam, patients should be warned to immediately notify the attending physician of any symptoms of depression or suicidal intentions.
Use in Pediatrics
The available information on the use of levetiracetam in children does not indicate any negative effect on development and puberty. However, the long-term effects of treatment on children's ability to learn, their intellectual development, growth, endocrine gland functions, sexual development and fertility remain unknown.
Impact on the ability to drive vehicles and manage mechanisms
Due to the different individual sensitivity to levetiracetam from the side of the central nervous system during the period of treatment, patients should refrain from driving vehicles and practicing potentially dangerous activities that require an increased concentration of attention and speed of psychomotor reactions.
DRUG INTERACTION
With joint admission with topiramate, the probability of anorexia is higher.
Completeness of absorption of levetiracetam does not change under the influence of food, while the rate of absorption is somewhat reduced.
