#特殊劑型：不建議磨粉、管灌藥品

治療癲癇 Partial seizures (In combination with other anticonvulsant agents)
#仿單變更2022

Antiseizure Agent, Miscellaneous
A triazine derivative which inhibits release of glutamate (an excitatory amino acid) and inhibits voltage-sensitive sodium channels, which stabilizes neuronal membranes. Lamotrigine has weak inhibitory effect on the 5-HT3 receptor; in vitro inhibits dihydrofolate reductase.

Patients with known hypersensitivity to the drug or any ingredient in the formulation.

C

Lamotrigine is distributed into milk. A decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.

Common:
Dizziness, headache, ataxia, nausea, vomiting, rhinitis, pharyngitis, diplopia, blurred vision
Serious:
1. Stevens Johnson syndrome or rare deaths due to toxic epidermal necrolysis
2. Serious skin rashes: The incidence of rashes is higher in pediatric patients than in adults receiving lamotrigine.<20220329>
3. Cardiac conduction abnormalities<20220329>

Bipolar disorder, maintenance:
1. Patients not taking interacting medications:
Weeks 1 and 2: 25 mg/day, Weeks 3 and 4: 50 mg/day, Week 5: 100 mg/day, Week 6: 200 mg/day; increase based on response and tolerability
2. Patients taking valproate (inhibits lamotrigine metabolism):
Weeks 1 and 2: 25 mg every other day, Weeks 3 and 4: 25 mg/day, Week 5: 50 mg/day, Week 6 and maintenance: 100 mg/day; increase based on response and tolerability
3. Patients taking drug(s) that induce lamotrigine metabolism (eg, carbamazepine, phenytoin, others) but not taking valproate:
Weeks 1 and 2: 50 mg/day, Weeks 3 and 4: 100 mg/day, Week 5: 200 mg/day, Week 6: 300 mg/day, Maintenance: ≤400 mg/day; increase based on response and tolerability
Focal (partial) onset seizures and generalized onset seizures:
1. Patients not taking interacting medications:
Weeks 1 and 2: 25 mg/day, Weeks 3 and 4: 50 mg/day, Week 5 and beyond: increase by 50 mg/day every 1 to 2 weeks; Usual maintenance dose 225 to 375 mg/day
2. Patients taking valproate (inhibits lamotrigine metabolism):
Weeks 1 and 2: 12.5 to 25 mg every other day, Weeks 3 and 4: 25 mg/day, Week 5 and beyond: 50 mg/day, Week 6 and maintenance: 100 mg/day; increase based on response and tolerability

The drug is not approved for use in patients below 16 of age, due to higher incidence of severe life-threatening skin rash than in adult.

1. Mild to severe impairment: No dosage adjustment necessary
2. CrCl <30 mL/minute: some pharmacokinetic parameters (eg, half-life) may vary considerably; titrate with caution
3. Hemodialysis: Slightly dialyzable; no dosage adjustment necessary; supplemental doses are generally not required
4. Peritoneal dialysis: Unlikely to be significantly dialyzable; No dosage adjustment necessary; titrate with caution
5. CRRT, PIRRT: Some dialyzability expected but no specific data available: No initial dosage adjustment necessary

1. Mild impairment: No dosage adjustment necessary.
2. Moderate to severe impairment without ascites: Decrease initial, escalation, and maintenance doses by ~25%; adjust according to clinical response and tolerance
3. Moderate to severe impairment with ascites: Decrease initial, escalation, and maintenance doses by ~50%; adjust according to clinical response and tolerance.