Lamotrigine (Page 2 of 12)

2.2 Adjunctive Therapy for Primary Generalized Tonic-Clonic and Partial-Onset Seizures

This section provides specific dosing recommendations for patients aged 13 years and older. Specific dosing recommendations are provided depending upon concomitant AEDs or other concomitant medications.

Table 1 Escalation Regimen for Lamotrigine Extended-Release in Patients Aged 13 Years and Older

a Valproate has been shown to inhibit glucuronidation and decrease the apparent clearance of lamotrigine [see Drug Interactions (7), Clinical Pharmacology (12.3)].

b Drugs that induce lamotrigine glucuronidation and increase clearance, other than the specified antiepileptic drugs, include estrogen-containing oral contraceptives, rifampin, and the protease inhibitors lopinavir/ritonavir and atazanavir/ritonavir. Dosing recommendations for oral contraceptives and the protease inhibitor atazanavir/ritonavir can be found in General Dosing Considerations [see Dosage and Administration (2.1)]. Patients on rifampin and the protease inhibitor lopinavir/ritonavir should follow the same dosing titration/maintenance regimen used with antiepileptic drugs that induce glucuronidation and increase clearance [see Dosage and Administration (2.1), Drug Interactions (7), Clinical Pharmacology (12.3)].

c Dose increases at week 8 or later should not exceed 100 mg daily at weekly intervals.

In Patients TAKING Valproatea In Patients NOT TAKING Carbamazepine, Phenytoin, Phenobarbital, Primidone,b or Valproatea In Patients TAKING Carbamazepine, Phenytoin, Phenobarbital, or Primidoneb and NOT TAKING Valproatea
Weeks 1 and 2 25 mg every other day 25 mg every day 50 mg every day
Weeks 3 and 4 25 mg every day 50 mg every day 100 mg every day
Week 5 50 mg every day 100 mg every day 200 mg every day
Week 6 100 mg every day 150 mg every day 300 mg every day
Week 7 150 mg every day 200 mg every day 400 mg every day
Maintenance range (week 8 and onward) 200 to 250 mg every dayc 300 to 400 mg every dayc 400 to 600 mg every dayc

2.3 Conversion from Adjunctive Therapy to Monotherapy

The goal of the transition regimen is to attempt to maintain seizure control while mitigating the risk of serious rash associated with the rapid titration of lamotrigine extended-release.

To avoid an increased risk of rash, the recommended maintenance dosage range of lamotrigine extended-release as monotherapy is 250 to 300 mg given once daily.

The recommended initial dose and subsequent dose escalations for lamotrigine extended-release should not be exceeded [see Boxed Warning].

Conversion from Adjunctive Therapy with Carbamazepine, Phenytoin, Phenobarbital, or Primidone to Monotherapy with Lamotrigine Extended-Release

After achieving a dose of 500 mg/day of lamotrigine extended-release using the guidelines in Table 1, the concomitant enzyme-inducing AED should be withdrawn by 20% decrements each week over a 4-week period. Two weeks after completion of withdrawal of the enzyme-inducing AED, the dosage of lamotrigine extended-release may be decreased no faster than 100 mg/day each week to achieve the monotherapy maintenance dosage range of 250 to 300 mg/day.

The regimen for the withdrawal of the concomitant AED is based on experience gained in the controlled monotherapy clinical trial using immediate-release lamotrigine.

Conversion from Adjunctive Therapy with Valproate to Monotherapy with Lamotrigine Extended-Release

The conversion regimen involves the 4 steps outlined in Table 2.

Table 2 Conversion from Adjunctive Therapy with Valproate to Monotherapy with Lamotrigine Extended-Release in Patients Aged 13 Years and Older with Epilepsy
Lamotrigine Extended-Release Valproate
Step 1 Achieve a dose of 150 mg/day according to guidelines in Table 1. Maintain established stable dose.
Step 2 Maintain at 150 mg/day. Decrease dose by decrements no greater than 500 mg/day/week to 500 mg/day and then maintain for 1 week.
Step 3 Increase to 200 mg/day. Simultaneously decrease to 250 mg/day and maintain for 1 week.
Step 4 Increase to 250 or 300 mg/day. Discontinue.

Conversion from Adjunctive Therapy with Antiepileptic Drugs other than Carbamazepine, Phenytoin, Phenobarbital, Primidone, or Valproate to Monotherapy with Lamotrigine Extended-Release

After achieving a dosage of 250 to 300 mg/day of lamotrigine extended-release using the guidelines in Table 1, the concomitant AED should be withdrawn by 20% decrements each week over a 4-week period. No adjustment to the monotherapy dose of lamotrigine extended-release is needed.

2.4 Conversion from Immediate-Release Lamotrigine Tablets to Lamotrigine Extended-Release Tablets

Patients may be converted directly from immediate-release lamotrigine to lamotrigine extended-release tablets. The initial dose of lamotrigine extended-release should match the total daily dose of immediate-release lamotrigine. However, some subjects on concomitant enzyme-inducing agents may have lower plasma levels of lamotrigine on conversion and should be monitored [see Clinical Pharmacology (12.3)].

Following conversion to lamotrigine extended-release, all patients (but especially those on drugs that induce lamotrigine glucuronidation) should be closely monitored for seizure control [see Drug Interactions (7)]. Depending on the therapeutic response after conversion, the total daily dose may need to be adjusted within the recommended dosing instructions (see Table 1).

All MedLibrary.org resources are included in as near-original form as possible, meaning that the information from the original provider has been rendered here with only typographical or stylistic modifications and not with any substantive alterations of content, meaning or intent.

This site is provided for educational and informational purposes only, in accordance with our Terms of Use, and is not intended as a substitute for the advice of a medical doctor, nurse, nurse practitioner or other qualified health professional.

Privacy Policy | Copyright © 2022. All Rights Reserved.