Lamictal has the main active ingredient: lamotrigine, indicated to treat epilepsy and prevent mood swings in patients with bipolar disorder. The drug is manufactured by Glaxo Smith Kline (GSK) in tablet form, 50mg strength. So, what is the effect of Lamictal 50 mg, let's find out through the article below.
1. What is Lamictal 50 mg?
Lamictal 50 mg is a psychotropic drug, used to treat patients with epileptic seizures, typical absence seizures, depression, bipolar disorder.
The main ingredient in Lamictal 50 mg is Lamotrigine, a use-dependent inhibitor of voltage-gated sodium channels. At the same time, it also inhibits the pathological release of glutamate and inhibits the sudden burst of action potentials that release glutamate.
Lamictal 50 mg is rapidly and completely absorbed in the intestine, with very little first-pass metabolism in the liver. The drug binds to plasma proteins by about 55%, UDP-glucuronyl transferase is the enzyme responsible for metabolizing lamotrigine.
The drug’s clearance is mainly in the form of metabolism with subsequent excretion of the glucuronide conjugate in the urine, only 2% of the drug metabolites are excreted in the feces
2. Uses and indications of Lamictal 50 mg
Lamictal 50 mg is indicated in these cases:
- Partial epilepsy and generalized epilepsy.
- Tonic-clonic seizures and seizures in Lennox-Gastaut syndrome.
- Typical absence seizures.
- Bipolar disorder, mood swings, prevention of depressive episodes.
3. Contraindications of Lamictal 50 mg
Lamictal 50 mg is not used in the following cases:
- The patient is hypersensitive to lamotrigine or any ingredient of the drug.
- Acute hepatitis.
- Chronic hepatitis.
- Drug-induced hepatitis.
4. Usage and dosage of Lamictal 50 mg
Usage: The drug is produced in tablet form, should be taken with water, do not break the tablet in half or crush the drug.
Dosage:
- Treatment of epilepsy:
- For adults and children over 12: The starting dose in monotherapy is 25mg/time/day for 2 weeks, then 50mg/time/day for the next 2 weeks. Continue to increase the dose, maximum from 50 to 100mg every 1 to 2 weeks until the patient gets an effective response, then maintain. The maintenance dose to get maximum response is 100 to 200 mg/day, taken orally, divided into 1-2 times a day. In severe cases, the dose may be up to 500 mg Lamictal/day to get the expected response.
- For children from 2 to 12: Typical absence seizures: First two weeks: 0.3 mg/kg, taken orally divided into 1-2 times a day. Next two weeks: dose of 0.6 mg/kg, taken orally divided into 1-2 times a day. Maintenance dose: 1-10 mg/kg/day, taken orally 1-2 times a day, up to a maximum of 200 mg/day.
- When combined with valproate: First two weeks: 0.15 mg/kg (once a day). Next two weeks: 0.3 mg/kg (once a day). Maintenance dose: 1 - 5 mg/kg/day (divided into 1 or 2 doses) up to a maximum of 200 mg/day.
- Children under 2 years of age: The drug has not been studied as monotherapy in children under 2 years of age or as combination therapy in children under 1 month of age. Therefore, the safety and efficacy of Lamotrigine in the combined treatment of partial seizures in children from 1 month to 2 years of age are not known, so Lamictal should not be used in children under 2 years of age.
- Treatment of bipolar disorder:
- Adults over 18 years of age: Combined treatment with valproate: First two weeks: 12.5 mg (taken 25 mg every other day). Next two weeks: 25 mg (once a day). One week later: 50 mg (divided into 1 or 2 doses/day). Maintenance dose to be taken (next week): 100 mg (divided into 1 or 2 doses/day) up to a maximum dose of 200 mg/day. When not combined with valproate, the drug can be used as follows: First two weeks: 50 mg (once daily). Next two weeks: 100 mg (divided twice daily). One week later: 200 mg (divided twice daily). Maintenance dose to be taken (week 6): 300 mg/day, increased to 400 mg/day if necessary in week 7 (divided twice daily). When monotherapy with Lamictal, dosage is: First two weeks: 25 mg (once daily). Next two weeks: 50 mg (divided once or twice daily). Next week: 100 mg (divided once or twice daily). Maintenance dose to be taken (week 6): 200 mg (from 100 to 400 mg) (divided once or twice daily).
- Children under 18 years of age: Safety and efficacy have not been known in this age group, so it should not be indicated.
- The dosage of Lamictal 50 mg above is only for reference, the specific dosage depends on the physical condition and the disease progression. For an appropriate and safe dosage, you need to consult your doctor or health professional.
5. Side effects of Lamictal 50 mg
Common side effects:
- Rash, redness on the skin.
- Irritability.
- Insomnia, dizziness, vertigo.
- Nausea, diarrhea.
- Aching bones and joints.
Uncommon side effects:
- Hypersensitivity to drug ingredients.
- Hallucinations, blurred vision, double vision.
- Conjunctivitis.
- Liver dysfunction.
If you experience any side effects of the drug, stop using it and immediately notify your doctor or go to the nearest healthcare facility for timely treatment.
6. Drug interactions of Lamictal 50 mg
Lamictal 50 mg may interact with other drugs:
- Glucuronidation inhibitors may affect the clearance of lamotrigine, increasing the metabolism of lamotrigine.
- Combined oral contraceptives increase the clearance of oral lamotrigine by approximately 2-fold.
- Interaction with substances that are mainly eliminated by the OCT 2 pathway with a narrow therapeutic index such as dofetilide because Lamictal inhibits renal tubular secretion via the OCT 2 protein.
7. Handle overdose or missed dose
- What should you do if you overdose? Symptoms of drug overdose: Nystagmus, loss of motor coordination, decreased consciousness, grand mal seizures and coma, ECG shows a wide QRS complex in overdosed patients. 10 - 20 times higher doses than the maximum therapeutic dose can lead to death. In case of overdose, the patient should be hospitalized and monitored for timely treatment.
- What should you do if you miss a dose? Take the dose as soon as you remember. However, if the interval between the next dose is too short, skip the missed dose and continue taking the next dose on schedule. Do not take a double dose to make up for a missed dose.
8. Precautions when using Lamictal 50 mg
Before using the drug, you need to pay attention to the instructions of the doctor and read the instructions carefully:
- Skin rashes usually appear within 8 weeks after starting treatment with Lamictal and most of these rashes are mild and self-limiting. Caution should be exercised when using the drug for patients with a history of allergies or rashes when taking other antiepileptic drugs.
- Hemophagocytic syndrome occurs when taking Lamictal.
- Signs of depression and/or bipolar disorder may appear in patients with epilepsy and there is evidence of a high risk of suicide in patients with epilepsy and bipolar disorder.
- You should closely monitor for clinical signs of worsening and suicidality in patients using Lamictal to treat bipolar disorder.
- Patients using combination oral contraceptives in cases where higher maintenance doses of lamotrigine (up to double) are needed to get maximum therapeutic response. In addition, note that Lamictal may also reduce the effectiveness of oral contraceptives in some patients using hormonal preparations with Lamictal.
- Caution should be exercised when used in patients with Brugada syndrome.
- Lamictal should not be stopped abruptly as it can cause reactive seizures, you should gradually reduce the dose of Lamictal over 2 weeks unless it is necessary to stop suddenly for safety reasons (such as rash).
- Only use Lamictal during pregnancy with the consent of a doctor, clearly determining the benefits outweigh the risks to the body.
- The drug is excreted in breast milk at very variable concentrations, resulting in lamotrigine concentrations in infants reaching nearly 50% of maternal concentrations. Therefore, the benefits of breastfeeding should be weighed against the risk of side effects in infants.
The above is some information on the uses, indications, and dosage of Lamictal 50 mg. If you need advice or have any questions, please consult a qualified doctor/pharmacist/health professional for answers.
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