Product Dossier

APX-LAMOTRIGINE

Product Dossier for APX-LAMOTRIGINE (lamotrigine, Arrotex Pharmaceuticals). ARTG record, PBS listing, PBAC outcomes — compiled by arcimedes.

What it is

APX-LAMOTRIGINE is lamotrigine, available as dispersible/chewable tablets in strengths of 25 mg, 50 mg, 100 mg and 200 mg.

Approved indications —

Partial seizures in adults and children. — Generalised seizures in adults and children.

Dosing overview

For monotherapy in adults and children over 12 years of age, the initial dose is 25 mg once daily for two weeks, followed by 50 mg once daily for two weeks, then increased by a maximum of 50 to 100 mg every one to two weeks until optimal response is achieved. The usual maintenance dose is 100 to 200 mg per day given once daily or as two divided doses. For add-on therapy in patients taking sodium valproate, the initial dose is 25 mg every alternate day for two weeks, followed by 25 mg once daily for two weeks, then increased by a maximum of 25–50 mg every one to two weeks. The usual maintenance dose is 100 to 200 mg per day given once daily or as divided dose. For add-on therapy in patients not taking sodium valproate, the initial dose is 50 mg once daily for two weeks, followed by 100 mg per day in two divided doses for two weeks, then increased by a maximum of 100 mg every one to two weeks. The usual maintenance dose is 200 to 400 mg per day as a divided dose. As the minimum strength available is the 25 mg tablet, other lamotrigine products with 2 mg and 5 mg strengths should be used instead of APX-LAMOTRIGINE if the calculated dose is less than 25 mg.

Key safety warnings

The risk of serious rash is associated with high initial doses and exceeding the recommended dose escalation for lamotrigine. Careful incremental titration of the dose may decrease the severity of skin rashes. When restarting lamotrigine in patients who have discontinued it for any reason, prescribers should assess the need for escalation to maintenance dose, as the greater the interval of time since the previous dose, the more consideration should be given to escalation to the maintenance dose. It is recommended that lamotrigine not be restarted in patients who have discontinued due to rash associated with prior treatment with lamotrigine unless the potential benefit clearly outweighs the risk.

Regulatory history

APX-LAMOTRIGINE was first listed on the Australian Register of Therapeutic Goods on 27 August 2020, with four strengths registered: 25 mg, 50 mg, 100 mg and 200 mg dispersible/chewable tablets.