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Lamitor
Last reviewed: 23.04.2024
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Lamitor is an effective anticonvulsant, used for various convulsive syndromes.
Indications Lamitor
Lamitor is indicated for both monotherapy and combined treatment course, for adults, and also for children aged 12+ years with such violations:
- simple or complex partial seizures;
- secondary or primary form of generalized tonic-clonic seizures;
- simple and complex absence;
- myoclonic seizures;
- Attacks that have resistance to other anticonvulsants.
In addition, the medicine can be used as an auxiliary tool - children 2-12 years old.
Release form
Produced in the form of tablets in a volume of 25, 50 or 100 mg. One blister contains 10 tablets. In one pack 3 or 5 blister plates are packed.
Pharmacodynamics
Lamotrigine is an effective blocker of potential-dependent sodium channels located in presynaptic neuronal membranes. It eliminates the excess of the released 2-aminopentanedioic acid (a neurotransmitter involved in the development of seizures of epilepsy), as well as the associated spread of transmitted impulses.
Pharmacokinetics
Lamotrigine is absorbed fairly quickly from the intestine and almost does not participate in the presystemic metabolic process of the so-called "first pass". The peak concentration inside the plasma substance reaches approximately 2.5 hours after the drug is consumed.
The peak concentration period is prolonged if you take the medicine along with the food, but the suction rate remains the same. There are noticeable interindividual fluctuations in the peak concentration of equilibrium, but each individual patient has such fluctuations. The indicator of binding to plasma proteins is about 55%. The distribution volume is 0.92-1.22 l / kg.
In the metabolism involved enzyme UDF-GT. Depending on the dosage, lamotrigine may slightly increase its own metabolism. The equilibrium coefficient of cleansing of the active substance in adults is 39 ± 14 ml / min (average).
Metabolized to the state of glucuronides, which are then excreted mainly together with urine (less than 10% of the substance is excreted unchanged). Another 2% is excreted with feces.
The half-life (in adults it is 24-35 hours on average) and the coefficient of cleansing do not depend on the dosage. The indicator of the cleansing factor of the active substance is reduced by 32% in patients with constitutional hyperbilirubinemia, but it does not go beyond the standard values. For the half-life of lamotrigine is strongly influenced by drugs, taken in combination with Lamitor.
The active substance is excreted together with the mother's milk (concentration is 40-60% of the indices in the plasma). Sometimes in infants, plasma concentrations reached therapeutic levels.
The parameters of the clearance of the active component in children (in accordance with the weight) exceed the similar level in adults. The highest coefficient is observed in children under 5 years old. Half-life is shorter than in adult patients. The average is 7 hours (in the case of combination with drugs that induce glucuron) and can increase up to 45-50 hours (in case of combination with valproate).
Dosing and administration
Initially, the dosage of drugs for children 12+, as well as adults (not taking sodium valproate, but taking other anticonvulsants that induce isoenzymes) is 50 mg once a day (the first 2 weeks, and then 100 mg 2 times) (per day) for the next 2 weeks. After that, the dosage should be increased to 200-400 mg (twice a day).
Initially, the dosage of drugs to patients who take sodium valproate, combined with other anticonvulsants inducing isoenzymes, is 25 mg every other day for 2 weeks, and then 25 mg daily for the next 2 weeks. Further, the dosage is increased until the optimal therapeutic effect is obtained. The maintenance dosage is 100-200 mg (for 1 or 2 doses).
The initial dosage for patients aged 2-12 years (with Lamitor monotherapy) is 2 mg / kg twice a day (2 weeks) and then 5 mg / kg twice a day for another 2 weeks. The size of the maintenance dose is 5-15 mg / kg twice a day.
The initial dosage of the drug for children (combined course of treatment) is 0.2 mg / kg daily for 2 weeks, and then 0.5 mg / kg daily for the next 2 weeks. Further, the dosage is increased until the optimal therapeutic effect is obtained. The size of the maintenance dose is 1-5 mg / kg (1-2 times per day).
Use Lamitor during pregnancy
Prescribe a drug during pregnancy is prohibited (except when the possible benefits of treatment exceed the potential risk for the child).
Contraindications
Among the contraindications:
- severe disorders in the liver;
- lactation period;
- age younger than 3 years;
- individual intolerance to lamotrigine or other components of the drug.
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Side effects Lamitor
Adverse reactions that occur when taking the drug with monotherapy:
- CNS organs: headaches with dizziness, sleep disorders or drowsiness, as well as increased fatigue;
- Organs of the digestive system: nausea;
- Allergy: a skinlike rash on the skin (2%), which is usually observed in the first month after the start of the course of treatment and comes off after the drug is withdrawn. Occasionally, malignant exudative erythema, Lyell's syndrome or Quincke's edema may develop.
Adverse reactions in the case of taking Lamitor as an auxiliary therapeutic agent in the course of treatment with standard antiepileptic drugs:
- organs of the central nervous system: in addition to the above - aggressiveness and irritability, balance disorder, confusion and tremor;
- organs of vision: visual acuity disorder, as well as diplopia;
- organs of the hematopoietic system: neutro-, and also leukopenia;
Organs of the digestive system: dyspeptic symptoms and vomiting with nausea.
[2]
Overdose
Among the signs of an overdose: in the case of a single dose that exceeds the maximum permissible limit by 10-20 times, ataxia, consciousness disorder, nystagmus, and also coma can develop.
Symptoms require hospitalization with supportive treatment depending on the clinical presentation.
Interactions with other drugs
As a result of the combination with drugs stimulating the process of glucuronization (phenytoin or carbamazepine), the average half-life is reduced (up to about 14 hours). When combined with valproate, this indicator increases to 70 hours.
Valproates have a powerful inhibitory effect on the process of glucuronization of the active substance Lamitor.
Such drugs as phenytoin, carbamazepine, as well as phenobarbital and primidone, and besides this, ethinylestradiol / levonorgestrel and rifampicin stimulate the process of glucuronization of lamotrigine.
Valproate, which inhibits the process of glucuronization of lamotrigine, is able to slow its metabolism, and also to prolong the average half-life almost 2 times.
Some of the above antiepileptic drugs (for example, phenobarbital with phenytoin, as well as carbamazepine with primidone), which stimulate metabolic hepatic enzymes, accelerate the processes of glucuronization and lamotrigine metabolism.
When carbamazepine was combined with lamotrigine, adverse reactions such as ataxia, nausea and loss of visual acuity were manifested, and in addition dizziness and diplopia. These manifestations usually disappeared after a reduction in the dosage of carbamazepine.
Alansapine at a dosage of 15 mg reduces the peak concentration and AUC, respectively, by 20% and 24% on average. But such changes basically do not affect the clinical picture of treatment.
The suppression of lamotrigine with drugs such as fluoxetine, amitriptyline, clonazepam, haloperidol, bupropion or lorazepam has little effect on the formation of the primary product of lamotrigine-2-N-glucuronide decomposition.
When combined oral contraceptives are used (30 μg of ethinylestradiol and 150 μg of levonorgestrel), the lamotrigine cleansing factor is approximately 2-fold (after oral administration), which decreases AUC and a peak of lamotrigine concentration by 52% , and 39%, respectively (on average).
When combined with lamotrigine, there is a slight increase in the levonorgestrel cleansing factor, which accounts for 19% and 12% of its AUC and peak concentration, respectively.
Rifampicin increases the rate of lamotrigine clearance, and also shortens its half-life, because this drug stimulates the activity of hepatic enzymes that perform the glucuronization process. Patients taking rifampicin as a concomitant medication should be given a special regimen for lamotrigine - according to the regimen prescribed when lamotrigine is combined with drugs that stimulate the glucuronidation process.
Storage conditions
It is required to keep the medicine in a place that is closed from moisture, sunlight, and access of children. Temperature conditions - no more than 30 ° С.
Shelf life
Lamitor is allowed to be used for 3 years from the date of manufacture of the medicine.
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Attention!
To simplify the perception of information, this instruction for use of the drug "Lamitor" translated and presented in a special form on the basis of the official instructions for medical use of the drug. Before use read the annotation that came directly to medicines.
Description provided for informational purposes and is not a guide to self-healing. The need for this drug, the purpose of the treatment regimen, methods and dose of the drug is determined solely by the attending physician. Self-medication is dangerous for your health.