Clinical trial NCT00913107: Efficacy and Safety Study of Lamotrigine to Treat Trigeminal Neuralgia
Official title: Lamotrigine in Trigeminal Neuralgia: Efficacy and Safety in Comparison With Carbamazepine
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
PHASE3
Conditions: Trigeminal Neuralgia
Keywords: Trigeminal Neuralgia
Lamotrigine
Carbamazepine
Lamictal®
Tegretol®
Lead sponsor: University of Malaya
Sponsor class: OTHER
First posted: 2009-06-03
Enrollment: 21
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: The purpose of this study was to determine the efficacy and safety of lamotrigine in patients with trigeminal neuralgia (TGN).

Detailed description: Trigeminal Neuralgia (TGN) is a rare form of chronic facial pain shrouded in mystery, although not life threatening, can be excruciating painful and extraordinarily debilitating. Its uniqueness and peculiarity can be ascertained by the fact that TGN may present to and be managed by dentists, neurologists, neurosurgeons, oral surgeons and ear, nose and throat surgeons.

The management of TGN is initially medical, with the "gold standard" drug of carbamazepine (CBZ). Whilst CBZ continues to be the treatment of choice, a substantial proportion of patients tolerate this drug poorly, predominantly because of side-effects that include drowsiness, accommodation disorders, hepatitis, elevation in liver enzymes, renal dysfunction, congestive heart failure, delayed multi-organ failure, leucopenia, thrombocytopenia etc. etc. If pain-relief is incomplete with CBZ or it produces adverse side-effects, options include using an alternative second-line medical agent. The drugs suggested to be considered as second-line agents for the treatment of TGN, include: lamotrigine, baclofen, phenytoin, oxcarbazepine, gabapentin, clonazepam, valproate, mexiletine, and topiramate.

Lamotrigine (LTG), a novel anticonvulsant, which has not been adequately assessed for its antineuralgic properties. It has a bimodal mechanism of action:

* inhibits the release of glutamate and aspartate by blocking voltage-sensitive sodium channels
* antagonistic at neuroexcitatory N-methyl-d-aspartate receptors.

It can also acts at and inhibits calcium channels to enhance the gamma- Aminobutyric acid (GABA) synthesis. GABA is an inhibitory amino acid neurotransmitter that decreases neural membrane action potentials and therefore decreases nerve excitability. Glutamate has been implicated in the mechanisms contributing towards phenomenon of chronic pain, such as sensitisation and wind up. LTG through its inhibition of pathological release of glutamate, has the potential towards management of chronic pain, particularly of neuropathic origin.

Lamotrigine, therefore has the potential to be a promising new treatment for TGN.

Eligibility criteria: Inclusion Criteria:

* Clinical diagnosis of Trigeminal Neuralgia
* Male; or non-pregnant/non-lactating female
* Must be willing to cooperate with and understands study instructions
* Signed informed consent prior to entering study

Exclusion Criteria:

* psychiatric illness
* severe liver or cardiovascular disease
* renal impairment, low white cell count
* malignancy
* pregnancy or lactation
* alcohol or recreational drug abuse
* and positive tests for human immunodeficiency virus or hepatitis B or C.

Primary outcomes:
measure: Pain-relief
timeFrame: 3-6 months
Secondary outcomes:
Other outcomes:
Locations:
city: Kuala Lumpur
country: Malaysia
facility: Dept. of OMOP, Faculty of Dentistry, University Malaya.
city: Kuala Lumpur
country: Malaysia
facility: Dept. of Oral Medicine and Oral Pathology, Faculty of Dentistry, University Malaya.
Study officials:
affiliation: Faculty of Dentistry, University Malaya
name: Dr. Sameer Shaikh, MDSc.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Shaikh S, Yaacob HB, Abd Rahman RB. Lamotrigine for trigeminal neuralgia: efficacy and safety in comparison with carbamazepine. J Chin Med Assoc. 2011 Jun;74(6):243-9. doi: 10.1016/j.jcma.2011.04.002. Epub 2011 May 10.