Lamotrigine Bioequivalence

Evaluation of Bioequivalence of Lamotrigine Tablets in Epileptic Patients

In this study, brand name lamotrigine (LAMICTAL) and generic lamotrigine will be compared in patients with epilepsy. Both the brand name and generic lamotrigine are approved by the Food and Drug Administration (FDA) and are commonly used to treat epilepsy. Some physicians and patients with epilepsy have believed that brand and generic lamotrigine have had clinically significant differences in efficacy and tolerability. The brand name and generic tablets have been shown to be the same when blood levels were measured in healthy volunteers without epilepsy, but these drugs have not yet been compared in patients with epilepsy. This study will do this comparison, by switching patients between brand and generic in a very structured manner, and seeing if the drugs are the same, primarily in terms of blood levels. Other comparisons will also be made secondarily, looking for any differences in adverse effects and seizure control.

Study Overview

• Status: Completed
• Conditions: Epilepsy
• Intervention / Treatment: Drug: Brand lamotrigine; Drug: Generic lamotrigine

Detailed Description

As is commonly done in a bioequivalence study, the null hypothesis is that the generic (i.e. test) is bioINequivalent to the brand name (i.e. reference). Hence, the alternative hypothesis is that the generic is bioequivalent to the brand name.

• Study Type: Interventional
• Enrollment (Actual): 35
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 63 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Subject is able to provide informed consent.
• Subject is male or female between 18 and 65 years of age inclusive.
• Subject has a diagnosis of epilepsy with simple partial seizures and/or complex partial seizures, with or without secondary generalization or primary generalized seizures.
• Subject has had a history of at least one seizure and/or AED related adverse event with AED changes; or had at least one seizure and/or AED related adverse event over the 12 months prior to Visit 1.
• Subject has been maintained on a stable dose regimen of anti-epileptic drugs (AEDs), including lamotrigine at 200mg, 400mg, or 600mg total daily dosage divided BID for at least 28 days prior to Visit 1. Additionally, subject must be taking lamotrigine for 8 weeks prior to Visit 1.
• Subject is willing to be switched between brand and generic lamotrigine.
• Subject is an acceptable candidate for venipuncture.
• Subject is willing to stop all OTC medications for 24 hours prior to and during 12 hour study visits.

Exclusion Criteria:

• Subject is currently participating or has participated within the last 2 months in any trial of an investigational drug or experimental device.
• Subject has a history of status epilepticus within the 12 month period prior to Visit 1.
• Subject has any medical condition, which in the opinion of the investigator, could jeopardize the subject's health or would compromise the subject's ability to participate in the trial.
• Subject has any psychiatric condition, which in the opinion of the investigator, could jeopardize the subject's health or would compromise the subject's ability to participate in this trial or confound the interpretation of the trial data.
• Subject has known hypersensitivity to lamotrigine.
• Subject has a medical condition that impacts drug absorption (e.g. gastric bypass surgery), including routine use (i.e. daily or weekly) use of acid blockers, antacids, anti-diarrhea, stimulants, appetite suppressants, or anti nausea medication or other drugs that modulate GI function.
• Subject has any history of alcohol or drug abuse within the previous two years.
• Subject has acute or subacutely progressive CNS disease.
• Subject has moderate or severe liver impairment as assessed by alanine aminotransferase (ALT), aspartate aminotransferase (AST), or total bilirubin levels ≥5 times the upper limit of normal (ULN).
• Subject has moderate or severe renal impairment as assessed by creatinine clearance lower than 50mL/min, using the Cockcroft-Gault formula.
• Female subjects of childbearing potential will not be eligible to participate who are unwilling or unable to use a medically acceptable method of contraception throughout the entire study period and for one week after the study is completed. Medically acceptable methods of contraception that may be used by the subject and/or her partner are: condom with spermicide, diaphragm with spermicide, IUD without progesterone, vaginal spermicidal suppository, surgical sterilization of their partner(s) or abstinence.
• Female subject is pregnant or nursing.
• Female subject is using hormonal contraceptive precautions including progesterone-coated IUD.
• Subjects is using hormonal replacement therapy.
• Subject is unwilling or unable to maintain their approximate daily smoking use during the study.
• Subject is using rifampin or other non-AED that strongly modulates lamotrigine levels.
• In addition to lamotrigine and/or vagus nerve stimulation and/or intermittent benzodiazepine use (e.g. lorazepam, diazepam, clonazepam), subject is taking more than two concomitant AEDs.
• Subject is not willing or able to be adherent to study protocol (e.g. dosing of lamotrigine and any interacting comedication).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Brand lamotrigine then Generic lamotrigine; Crossover trial. Each arm will receive Brand lamotrigine tablet for two periods and Generic lamotrigine for two periods.	Drug: Brand lamotrigine; Brand lamotrigine tablet 100mg tablets (1-3 either once or twice a day) for two weeks; Drug: Generic lamotrigine; Generic lamotrigine tablet 100mg tablets (1-3 either once or twice a day) for two weeks
Experimental: Generic lamotrigine then Brand lamotrigine; Crossover trial. Each arm will receive Generic lamotrigine tablet for two periods and Brand lamotrigine for two periods.	Drug: Brand lamotrigine; Brand lamotrigine tablet 100mg tablets (1-3 either once or twice a day) for two weeks; Drug: Generic lamotrigine; Generic lamotrigine tablet 100mg tablets (1-3 either once or twice a day) for two weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AUC	pharmacokinetic exposure (ng*hr/ml)	0-12hr
Cmax	highest concentration over the time duration 0-12hr (ng/ml)	0-12hr

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore
• Collaborators: Food and Drug Administration (FDA)

Publications and helpful links

General Publications

• Andermann F, Duh MS, Gosselin A, Paradis PE. Compulsory generic switching of antiepileptic drugs: high switchback rates to branded compounds compared with other drug classes. Epilepsia. 2007 Mar;48(3):464-9. doi: 10.1111/j.1528-1167.2007.01007.x.

Study record dates

Study Major Dates

• Study Start: May 1, 2012
• Primary Completion (Actual): October 1, 2013
• Study Completion (Actual): October 1, 2013

Study Registration Dates

• First Submitted: January 26, 2013
• First Submitted That Met QC Criteria: November 21, 2013
• First Posted (Estimate): November 27, 2013

Study Record Updates

• Last Update Posted (Actual): December 1, 2020
• Last Update Submitted That Met QC Criteria: November 5, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Keywords: epilepsy; bioequivalence; lamotrigine
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Antipsychotic Agents; Tranquilizing Agents; Psychotropic Drugs; Membrane Transport Modulators; Sodium Channel Blockers; Calcium-Regulating Hormones and Agents; Calcium Channel Blockers; Lamotrigine; Anticonvulsants
• Other Study ID Numbers: HP-00048923; HHSF223201010144A (Other Grant/Funding Number: HHS)