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Lamotrigine Dosage

Medically reviewed by Drugs.com. Last updated on Oct 9, 2023.

Applies to the following strengths: 25 mg; 100 mg; 150 mg; 200 mg; 5 mg; 50 mg; (green dose pack) 25 mg-100 mg; (orange dose pack) 25 mg-100 mg; (blue dose pack) 25 mg; 2 mg; (blue dose pack) 25 mg-50 mg; (green dose pack) 50 mg-100 mg-200 mg; (orange dose pack) 25 mg-50 mg-100 mg; 300 mg; (green dose pack) 50 mg-100 mg; 250 mg

Usual Adult Dose for Epilepsy

Risk of rash requires adhering to specific dose escalation regimens; the effect of lamotrigine glucuronidation inducers/inhibitors on lamotrigine drug levels necessitates dosing based on concomitant therapy

ADJUNCTIVE THERAPY: Immediate-Release (IR) Formulations:
For Patients Taking VALPROATE:

For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

ADJUNCTIVE THERAPY: Extended-Release (XR) Tablets:
For Patients Taking VALPROATE:
For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

MONOTHERAPY: For patients previously receiving carbamazepine, phenytoin, phenobarbital, primidone, or valproate as single antiepileptic therapy:
Immediate-release (IR):
Suggested Discontinuation of Concomitant Antiepileptic Drug (AED):

Extended-Release (XR):
Suggested Discontinuation of Concomitant Antiepileptic Drug (AED):

Conversion from IMMEDIATE-RELEASE (IR) to EXTENDED-RELEASE (XR)

Comments:

Uses: As adjunctive therapy for partial-onset and primary generalized tonic-clonic seizures; for use as monotherapy in patients with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone, or valproate as single antiepileptic therapy.

Usual Adult Dose for Bipolar Disorder

Risk of rash requires adhering to specific dose escalation regimens; the effect of lamotrigine glucuronidation inducers/inhibitors on lamotrigine drug levels necessitates dosing based on concomitant therapy

Immediate-Release Formulations Only:

Initial dose: Appropriate dose escalation is required; see below
Target dose: 200 mg/day; this dose may be higher or lower based on concomitant medications

For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:


For Patients Taking VALPROATE:

For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

Comments:

Use: Maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in patients treated for acute mood episodes with standard therapy.

Usual Adult Dose for Lennox-Gastaut Syndrome

Risk of rash requires adhering to specific dose escalation regimens; the effect of lamotrigine glucuronidation inducers/inhibitors on lamotrigine drug levels necessitates dosing based on concomitant therapy

Immediate-Release Formulations Only:

For Patients Taking VALPROATE:

For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

Comments:

Use: For adjunctive therapy of generalized seizures of Lennox-Gastaut syndrome.

Usual Pediatric Dose for Epilepsy

Risk of rash requires adhering to specific dose escalation regimens; the effect of lamotrigine glucuronidation inducers/inhibitors on lamotrigine drug levels necessitates dosing based on concomitant therapy

ADJUNCTIVE THERAPY:


Under 2 years: Not recommended

2 to 12 years:
For Patients Taking VALPROATE:
For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR and NOT taking VALPROATE:

Over 12 years:
For Patients Taking VALPROATE:
For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

ADJUNCTIVE THERAPY: Extended-Release (XR) Tablets

Under 13 years: Not Recommended

13 years or older:
For Patients Taking VALPROATE:
For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

MONOTHERAPY: For patients previously receiving carbamazepine, phenytoin, phenobarbital, primidone, or valproate as single antiepileptic therapy:
Under 16 years: Not Recommended
16 years or older: See Adult Dosing

Comments:

Uses: As adjunctive therapy in patients 2 years or older for partial-onset and primary generalized tonic-clonic seizures; for use as monotherapy in patients 16 years or older with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone, or valproate as single antiepileptic therapy.

Usual Pediatric Dose for Lennox-Gastaut Syndrome

Risk of rash requires adhering to specific dose escalation regimens; the effect of lamotrigine glucuronidation inducers/inhibitors on lamotrigine drug levels necessitates dosing based on concomitant therapy

Under 2 years: Not Recommended

Immediate-release formulations: Doses should be rounded down to the nearest whole tablet; a combination of only WHOLE tablets should be used for dosing

2 to 12 years:
For Patients Taking VALPROATE:

For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

Over 12 years:
For Patients Taking VALPROATE:
For Patients NOT Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, OR VALPROATE:
For Patients Taking CARBAMAZEPINE, PHENYTOIN, PHENOBARBITAL, PRIMIDONE, RIFAMPIN, or LOPINAVIR/RITONAVIR, and NOT taking VALPROATE:

Comments:

Use: For adjunctive therapy of generalized seizures of Lennox-Gastaut syndrome.

Renal Dose Adjustments

Use caution

Liver Dose Adjustments

Mild hepatic impairment: No adjustment recommended
Moderate and severe hepatic impairment without ascites: Decrease initial escalation and maintenance doses by approximately 25%; adjust doses based on clinical response
Severe hepatic impairment with ascites: Decrease initial escalation and maintenance doses by approximately 50%; adjust doses based on clinical response

Dose Adjustments

Therapeutic Drug Monitoring:


Concomitant use with Known Glucuronidation Inhibitors/Inducers:

Concomitant Use with Estrogen-Containing Oral Contraceptives:
Initial lamotrigine dose escalation: No adjustment recommended; follow dose-escalation guidelines based on concomitant AED or other concomitant medications
Maintenance lamotrigine dose:

STOPPING Estrogen-Containing Oral Contraceptives in Women on Lamotrigine:

Concomitant Use of Atazanavir/Ritonavir:
Initial lamotrigine dose escalation: No adjustment recommended; follow dose-escalation guidelines based on concomitant AED or other concomitant medications
Maintenance lamotrigine dose: For patients not taking glucuronidation inducers, may need to increase or decrease lamotrigine dose if atazanavir/ritonavir is added or discontinued, respectively.

Restarting Therapy:

Discontinuation Strategy:

Precautions

US BOXED WARNINGS: SERIOUS SKIN RASHES


CONTRAINDICATIONS:

Safety and effectiveness of extended-release (XR) have not been established in pediatric patients less than 13 years of age.
Safety and effectiveness of the immediate-release formulations have not been established in pediatric patients less than 2 years of age.

Consult WARNINGS section for additional precautions.

Dialysis

Hemodialysis: No specific guidelines provided; in a small study (n=6), about 20% of drug was removed by hemodialysis during a 4 hour session
Peritoneal dialysis: Data not available

Other Comments

Administration advice:


Tablets (Immediate-release and Extended-release):

Orally Disintegrating Tablets (ODT):

Chewable Dispersible Tablets:

MISSED DOSE: If a dose is missed, take as soon as remembered, if it is almost time for next dose, skip the missed dose and take the next dose at the scheduled time; do not take 2 doses at the same time

General:

Monitoring:

Patient advice:

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.