Prescribing Details
Description
Lamitrin is a preparation of Lamotrigine. The precise mechanism(s) by which Lamotrigine exerts its anticonvulsant action are unknown. Lamotrigine involves an effect on sodium channels. Lamotrigine inhibits voltage-sensitive sodium channels, thereby stabilizing neuronal membranes and consequently modulating presynaptic transmitter release of excitatory amino acids (e.g., glutamate and aspartate). The mechanisms by which Lamotrigine exerts its therapeutic action in bipolar disorder have not been established.
Uses
No Data
Indications
Lamitrin is indicated for:
i) Epilepsy-adjunctive therapy in patients aged 2 years and older:
- Partial-onset seizures
- Primary generalized tonic-clonic seizures (PGTC)
- Generalized seizures of Lennox-Gastaut syndrome
ii) Epilepsy-monotherapy in patients aged 16 years and older: Conversion to monotherapy in patients with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone or valproate as the single antiepileptic drug
iii) Bipolar disorder
Lamitrin ER is indicated for:
i) Adjunctive therapy for primary generalized tonic-clonic seizures and partial-onset seizures with or without secondary generalization in patients aged 13 years and older
ii) Conversion to monotherapy in patients aged 13 years and older with partial-onset seizures who are receiving treatment with a single antiepileptic drug
Dosage and administration
Route of administration: Lamitrin and Lamitrin ER tablets are taken in oral route. Lamitrin chewable/dispersible tablets should be placed onto the tongue and moved around in the mouth. LamitrinER tablets must be swallowed whole and must not be chewed, crushed or divided.
Lamitrin tablets
Epilepsy-Adjunctive therapy
| Table-1: Escalation regimen for Lamitrin in patients older than 12 years with epilepsy | |||
|---|---|---|---|
| In patients taking Valpoate | In patients not taking carbamazepine, phenytoin, phenobarbital, primidone or valproate | In patients taking carbamazepine, phenytoin, phenobarbital or primidone and not taking valproate | |
| Weeks 1 and 2 | 25 mg every other day | 25 mg everyday | 50 mg/day |
| Weeks 3 and 4 | 25 mg everyday | 50 mg/day | 100 mg/day (in 2 divided doses) |
| Week 5 onward to maintenance | Should be increased by 25 to 50 mg/day every 1 to 2 weeks | Should be increased by 50 mg/day every 1 to 2 weeks | Should be increased by 100 mg/day every 1 to 2 weeks |
| Usual maintenance dose | 100 to 200 mg/day with valproate alone. 100 to 400 mg/day with valproate and other drugs that induce glucuronidation (in 1 or 2 divided doses) |
225 to 375 mg/day (in 2 divided doses) | 300 to 500 mg/day (in 2 divided doses) |
| Table-2: Escalation regimen for Lamitrin in patients aged 2 to 12 years with epilepsy | |||
|---|---|---|---|
| In patients taking valproate | In patients not taking carbamazepine, phenytoin, phenobarbital, primidone or valproate | In patients taking carbamazepine, phenytoin, phenobarbital or primidone and not taking valproate | |
| Weeks 1 and 2 | 0.15 mg/kg/day in 1 or 2 divided doses (see Table-3 for weight-based dosing guide) | 0.3 mg/kg/day in 1 or 2 divided doses | 0.6 mg/kg/day in 2 divided doses |
| Weeks 3 and 4 | 0.3 mg/kg/day in 1 or 2 divided doses (see Table-3 for weight-based dosing guide) | 0.6 mg/kg/day in 2 divided doses | 1.2 mg/kg/day in 2 divided doses |
| Week 5 onward to maintenance | The dose should be increased every 1 to 2 weeks as follows: 0.3 mg/kg/day should be calculated and this should be added to the previously administered daily dose |
The dose should be increased every 1 to 2 weeks as follows: 0.6 mg/kg/day should be calculated and this should be added to the previously administered daily dose | The dose should be increased every 1 to 2 weeks as follows: 1.2 mg/kg/day should be calculated and this should be added to the previously administered daily dose |
| Usual maintenance dose | 1 to 5 mg/kg/day (maximum 200 mg/day in 1 or 2 divided doses). 1 to 3 mg/kg/day with valproate alone | 4.5 to 7.5 mg/kg/day (maximum 300 mg/day in 2 divided doses) | 5 to 15 mg(kg/day (maximum 400 mg/day in, 2 divided doses) |
| Maintenance dose in patients < 30 kg | May need to be increased by as much as 50%, based on clinical response | May need to be increased by as much as 50%, based on clinical response | May need to be increased by as much as 50%, based on clinical response |
| Table-3: The initial weight-based dosing guide for patients aged 2 to 12 years taking valproate (weeks 1 to 4) with epilepsy |
|||
|---|---|---|---|
| If the patient's weight is | Give this daily dose, using the most appropriate combination of Lamitrin 2 and 5 mg tablets | ||
| Greater than or equal | And less than or equal | Weeks 1 and 2 | Weeks 3 and 4 |
| 6.7 kg | 14 kg | 2 mg every other day | 2 mg everyday |
| 14.1 kg | 27 kg | 2 mg everyday | 4 mg everyday |
| 27.1 kg | 34 kg | 4 mg everyday | 8 mg everyday |
| 34.1 kg | 40 kg | 5 mg everyday | 10 mg everyday |
Epilepsy-Conversion from adjunctive therapy to monotherapy
The recommended maintenance dose of Lamitrin as monotherapy is 500 mg/day given in 2 divided doses. Conversion from adjunctive therapy with carbamazepine, primidone to monotherapy with Lamitrin:
After achieving a dose of 500 mg/day of Lamitrin using the guidelines in Table-1, the concomitant enzyme-inducing AED should be withdrawn by 20% decrements each week over a 4-week period.
Conversion from adjunctive therapy with valproate to monotherapy with Lamitrin:
| Table-4: Conversion from adjunctive therapy with valproate to monotherapy with Lamitrin in patients aged 16 years and older with epilepsy | ||
|---|---|---|
| Lamitrin | valproate | |
| Step 1 | A dose of 200 mg/day should be achieved according to guidelines in Table-1 | Established stable dose should be maintained. |
| Step 2 | Should be maintained at 200 mg/day. | Dose should be decreased by decrements not greater than 500 mg/day/week to 500 mg/day and then maintained for 1 week. |
| Step 3 | Should be increased to 300 mg/day and maintained for 1 week. | Should be simultaneously decreased to 250 mg/day and maintained for 1 week. |
| Step 4 | Should be increased by 100 mg/day every week to achieve maintenance dose of 500 mg/day. | Should be discontinued. |
Conversion from adjunctive therapy with antiepileptic drugs other than carbamazepine, phenytoin, phenobarbital, primidone or valproate to monotherapy with Lamitrin:
No specific dosing guidelines can be provided for conversion monotherapy with Lamitrin with AEDs other than carbamazepine, phenytoin, phenobarbital, primidone or valproate.
Bipolar disorder
| Table-5: Escalation regimen for Lamitrin in adults with bipolar disorder | |||
|---|---|---|---|
| In patients taking valproate | In patients not taking carbamazepine, phenytoin, phenobarbital, primidone or valproate | In patients taking carbamazepine, phenytoin, phenobarbital or primidone and not taking valproate | |
| Weeks 1 and 2 | 25 mg every other day | 25 mg daily | 50 mg daily |
| Weeks 3 and 4 | 25 mg daily | 50 mg daily | 100 mg daily, in divided doses |
| Weeks 5 | 50 mg daily | 100 mg daily | 200 mg daily, in divided doses |
| Weeks 6 | 100 mg daily | 200 mg daily | 300 mg daily, in divided doses |
| Weeks 7 | 100 mg daily | 200 mg daily | upto 400 mg daily, in divided doses |
Lamitrin ER tablets
Conversion from immediate-release Lamitrin tablets to Lamitrin ER
Patients may be converted directly from immediate-release Lamitrin to Lamitrin ER extended-release tablets. The initial dose of Lamitrin ER should match the total daily dose of immediate-release Lamitrin. Following conversion to Lamitrin ER, all patients should be closely monitored for seizure control. Depending on the therapeutic response after conversion, the total daily dose may need to be adjusted.
Use in pregnancy & lactation
Pregnancy: If therapy with lamotrigine is considered necessary during pregnancy, the lowest possible therapeutic dose is recommended.
Lactation: Lamotrigine is present in human milk. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for lamotrigine and any potential adverse effects on the breastfed infant from lamotrigine or from the underlying maternal condition.
Use in children and adolescents
Lamotrigine immediate release tablets are indicated as adjunctive therapy in patients aged 2 years and older for partial-onset seizures, the generalized seizures of Lennox-Gastaut syndrome and PGTC seizures. Safety and efficacy of lamotrigine immediate release tablets for the maintenance treatment of bipolar disorder for pediatric patients are not established. Safety and effectiveness of lamotrigine extended release tablets for any use in patients younger than 13 years have not been established.
Geriatric use
Precautions
Life-threatening serious rash and/or rash-related death may occur. Lamotrigine should be discontinued at the first sign of rash. The diagnosis of hemophagocytic lymphohistiocytosis should be considered and patients should immediately be evaluated if they develop signs or symptoms of systemic inflammation. On that case, lamotrigine should be discontinued. Multiorgan hypersensitivity reactions, also known as drug reaction with eosinophilia and systemic symptoms, may be fatal or life threatening. Early signs may include rash, fever and lymphadenopathy. These reactions may be associated with other organ involvement, such as hepatitis, hepatic failure, blood dyscrasias or acute multiorgan failure. On that case, lamotrigine should be discontinued. Lamotrigine could cause serious arrhythmias and/or death in patients with certain underlying cardiac disorders or arrhythmias. Blood dyscrasias (e.g., neutropenia, thrombocytopenia and pancytopenia) may occur. Patients should be monitored for signs of anemia, unexpected infection, bleeding, suicidal thoughts or behaviors and signs of meningitis.
Side effects
Most common side effects are dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, rhinitis, pharyngitis, rash, vomiting, infection, fever, accidental injury, diarrhea, abdominal pain, tremor, insomnia, back pain, fatigue and xerostomia.
Contraindications
Lamotrigine is contraindicated in patients with known hypersensitivity to lamotrigine or any other components of this product.
Drug interactions
Drug interaction with medication: Valproate increases lamotrigine concentrations more than 2-fold. Carbamazepine, phenytoin, phenobarbital, primidone and rifampin decrease lamotrigine concentrations. Estrogen containing oral contraceptives decrease lamotrigine concentration. Protease inhibitors e.g., lopinavir/ritonavir and atazanavir/lopinavir decrease lamotrigine exposure. Coadministration with organic cationic transporter 2 substrates with narrow therapeutic index is not recommended.
Drug interaction with food and others: Not applicable.
Overdose
Overdose may result in ataxia, nystagmus, seizures (including tonic-clonic seizures), decreased level of consciousness, coma and intraventricular conduction delay. There are no specific antidotes. Following a suspected overdose, hospitalization of the patient is advised. General supportive care is indicated, including frequent monitoring of vital signs and close observation of the patient. If indicated, emesis should be induced. Usual precautions should be taken to protect the airway.
Preparation
No Data
Pharmaceutical precautions
Store in a cool (below 30°C) and dry place protected from light. Keep away from the reach of children.
Presentation
Lamitrin 2 tablet: Each chewable/dispersible tablet contains Lamotrigine BP 2 mg.
Lamitrin 5 tablet: Each chewable/dispersible tablet contains Lamotrigine BP 5 mg.
Lamitrin 25 tablet: Each tablet contains Lamotrigine BP 25 mg.
Lamitrin 50 tablet: Each tablet contains Lamotrigine BP 50 mg.
Lamitrin ER 50 tablet: Each extended release tablet contains Lamotrigine BP 50 mg.
Lamitrin ER 100 tablet: Each extended release tablet contains Lamotrigine BP 100 mg.
Package quantities
Storage
Store in a cool (below 30°C) and dry place protected from light. Keep away from the reach of children.
Packing
Lamitrin 2 tablet: Carton of 30 tablets in blister pack.
Lamitrin 5 tablet: Carton of 30 tablets in blister pack.
Lamitrin 25 tablet: Carton of 30 tablets in blister pack.
Lamitrin 50 tablet: Carton of 30 tablets in blister pack.
Lamitrin ER 50 tablet: Carton of 30 tablets in blister pack.
Lamitrin ER 100 tablet: Carton of 30 tablets in blister pack.
