Safety of Long-term Use of Lamotrigine for the Treatment of Psychiatric Disorders

Efficacy and safety of lamotrigine in the treatment of bipolar disorder across the lifespan: a systematic review

BACKGROUND

Bipolar disorder (BD) is a cyclic mood disorder characterised by alternating episodes of mania/hypomania and depression interspersed with euthymic periods. Lamotrigine (LTG) demonstrated some mood improvement in patients treated for epilepsy, leading to clinical studies in patients with BD and its eventual introduction as maintenance therapy for the prevention of depressive relapse in euthymic patients. Most current clinical guidelines include LTG as a recommended treatment option for the maintenance phase in adult BD, consistent with its global licencing status.

AIMS

To review the evidence for the efficacy and safety of LTG in the treatment of all phases of BD.

METHODS

PubMed was searched for double-blind, randomised, placebo-controlled trials using the keywords: LTG, Lamictal, 'bipolar disorder', 'bipolar affective disorder', 'bipolar I', 'bipolar II', cyclothymia, mania, manic, depression, depressive, 'randomised controlled trial', 'randomised trial', RCT and 'placebo-controlled' and corresponding MeSH terms. Eligible articles published in English were reviewed.

RESULTS

Thirteen studies were identified. The strongest evidence supports utility in the prevention of recurrence and relapse, particularly depressive relapse, in stabilised patients. Some evidence suggests efficacy in acute bipolar depression, but findings are inconsistent. There is little or no strong evidence in support of efficacy in acute mania, unipolar depression, or rapid-cycling BD. Few controlled trials have evaluated LTG in bipolar II or in paediatric patients. Indications for safety, tolerability and patient acceptability are relatively favourable, provided there is slow dose escalation to reduce the probability of skin rash.

CONCLUSION

On the balance of efficacy and tolerability, LTG might be considered a first-line drug for BD, except for acute manic episodes or where rapid symptom control is required. In terms of efficacy alone, however, the evidence favours other medications.

An Unusual Etiology of Vocal Tremor in a Professional Singer

Vocal tremor is a neurologic disorder with myriad etiologies (eg, Parkinson disease, medications, or essential tremor). Vocal tremor can limit intelligibility and social interaction and can result in isolation in nonprofessional voice users. In a professional singer whose entire career is based on voice quality, onset of a vocal tremor is devastating. We report a case of sudden-onset vocal tremor that impeded a young professional singer's ability to perform and record her album. The etiology was determined to be a medication side effect of lamotrigine; a reaction that has not been previously reported. Diagnosis was based on perceptual assessment of the vocal tremor, laryngeal examination, and the singer's proximate history of lamotrigine dose adjustment. Two months after decreasing her dose, all symptoms resolved and the singer returned to her tour and performance schedule. To our knowledge, this is the first report of isolated vocal tremor as a side effect of lamotrigine and demonstrates that the voice may be more sensitive to this class of medication than previously described. It is incumbent on the vocal professional to inquire about and understand that new medication or dose changes may impact their voice.