RESEARCH TRIANGLE PARK, NC -- Dec. 17, 1998 -- The United States Food and Drug Administration has approved Glaxo Wellcome's anticonvulsant medication, Lamictal(R) (lamotrigine) for an expanded use in the treatment of people with epilepsy.
Adults with partial seizures, the most common form of epilepsy, can now convert to single drug therapy (monotherapy) with Lamictal if they are currently receiving treatment with a single enzyme inducing anti-epileptic drug (AED).
Lamictal has been available by prescription since 1994 as add-on therapy (prescribed in conjunction with other antiepileptic medications) for the treatment of partial seizures in adults with epilepsy. Lamictal received approval earlier this year for add-on therapy for generalised seizures in Lennox Gastaut syndrome (LGS). Lamictal is well tolerated and has been used by more than 1.4 million patients world-wide. In addition to the original compressed tablet formulation, Lamictal is also available in a new chewable, dispersible tablet.
Epilepsy is a condition that affects an estimated 2.5 million Americans, with approximately 125,000 new cases diagnosed each year. Partial seizures are the most common seizure type, affecting an estimated 65 percent of people with epilepsy. Partial seizures are the result of a localised disturbance that starts in just one part of the brain, affecting the physical or mental activity controlled by that area.
In the clinical study that led to the approval of this new indication, the treatment was evaluated in a 28-week study of 156 patients, ages 13-73, whose seizures were previously uncontrolled on their existing medication. Patients who participated in the study were converted from their existing medications to Lamictal monotherapy by adding Lamictal to their current treatment and then phasing out the current treatment over an eight week period.
More than twice as many patients in the group receiving Lamictal successfully completed monotherapy as in the group receiving the active control (56 percent versus 20 percent). It is important to note that the safety and effectiveness of Lamictal have not been established: 1) as initial monotherapy; 2) for conversion to monotherapy from non-enzyme inducing anti-epileptic drugs (AEDs) (for example valproate); or 3) for simultaneous conversion to monotherapy from two or more concomitant AEDs.
Most adverse events were mild-to-moderate and generally did not lead to discontinuation of Lamictal. The most common adverse events that occurred in greater than or equal to seven percent of patients in the monotherapy phase of treatment with Lamictal were dizziness (seven percent), nausea (seven percent), co-ordination abnormality (seven percent), vomiting (nine percent) and dyspepsia (seven percent). No patients taking Lamictal during the monotherapy phase reported somnolence as a side effect. Furthermore, patients generally reported a lower incidence of side effects in the monotherapy phase than the transition phase.
Serious rashes requiring hospitalisation and discontinuation of treatment have been reported. The incidence of these rashes, which have included Stevens-Johnson syndrome is approximately one percent in pediatric patients (age less than 16 years) and 0.3 percent in adults. In world-wide postmarketing experience, rare cases of toxic epidermal necrolysis and/or rash-related death have been reported, but their numbers are too few to permit a precise estimate of the rate. Lamictal should ordinarily be discontinued at the first sign of rash, unless the rash is clearly not drug-related. Prior to initiation of treatment with Lamictal, the patient should be instructed that a rash or other signs or symptoms of hypersensitivity (for example fever, lymphadenopathy) may herald a serious medical event and that the patient should report any such occurrence to a physician immediately.
A new chewable, dispersible form of Lamictal is available in 5 mg and 25 mg tablets. The new tablets can be chewed, swallowed whole or dissolved in liquid for administration by bottle or spoon for patients who have difficulty with administration, such as adults with disabilities and/or the elderly.
The medication also will remain available in its original tablet form for oral administration at 25 mg, 100 mg, 150 mg and 200 mg.
Thanks to The Doctor's Guide to the Internet™ for the article
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