Clozapine induced stuttering

Hallahan, Brian; Murray, Ivan; Doyle, P. G.

doi:10.1017/s079096670001048x

Cited by 9 publications

(11 citation statements)

References 8 publications

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“…Eight cases of clozapine-induced stuttering have been reported [Hallahan et al 2007;Lyall et al 2007;Begum, 2005;Duggal et al 2002;Supprian et al 1999;Thomas et al 1994]. These occurred at doses ranging between 125 mg [Thomas et al 1994] and 700 mg [Supprian et al 1999] with two authors suggesting a dose-dependent relationship [Hallahan et al 2007;Thomas et al 1994].…”

Section: Case Reportsmentioning

confidence: 99%

“…Three case reports associated clozapine-induced stuttering with seizure activity [Begum, 2005;Duggal et al 2002;Supprian et al 1999] and this view is supported by four cases where the use of valproate greatly improved speech difficulties [Lyall et al 2007;Begum, 2005;Duggal et al 2002;Supprian et al 1999], including facial tics as reported by Begum. Three patients went on to have a generalized seizure [Hallahan et al 2007;Duggal et al 2002;Supprian et al 1999].…”

Section: Case Reportsmentioning

confidence: 99%

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Clozapine-related EEG changes and seizures: dose and plasma-level relationships

Varma

Bishara

Besag

et al. 2011

Therapeutic Advances in Psychopharmacology

129

109

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Clozapine is a widely used atypical antipsychotic with a unique effectiveness in treatment-resistant schizophrenia. An important adverse effect is seizures, which have been observed at all stages of clozapine treatment. Valproate has traditionally been considered the drug of choice for the prophylaxis of clozapine seizures, however it may not be the most suitable choice for all patients. There is disagreement as to the best point to prescribe valproate or a suitable antiepileptic: as seizure prophylaxis at a certain clozapine dose or level, or only as remedial treatment. In this review, we examine the relevant literature with an aim to evaluate the following relationships: clozapine dose and electroencephalogram (EEG) abnormalities, plasma levels and EEG abnormalities, dose and occurrence of seizures and plasma levels and occurrence of seizures. Weighted linear regression models were fitted to investigate these relationships. There was a strong relationship between clozapine dose and plasma level and occurrence of clozapine-induced EEG abnormalities. However, a statistically significant relationship between dose and occurrence of seizures was not found. A relationship between clozapine plasma level and occurrence of seizures was not established because of the scarcity of useful data although our review found three case reports which suggested that there is a very substantial risk of seizures with clozapine plasma levels exceeding 1300 μg/l. Seizures are more common during the initiation phase of clozapine treatment, suggesting a slow titration to target plasma levels is desirable. An antiepileptic drug should be considered when the clozapine plasma level exceeds 500 μg/l, if the EEG shows clear epileptiform discharges, if seizures, myoclonic jerks or speech difficulties occur and when there is concurrent use of epileptogenic medication. The antiepileptics of choice for the treatment and prophylaxis of clozapine-induced seizures are valproate (particularly where there is mood disturbance) and lamotrigine (where there is resistance to clozapine).

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Section: Case Reportsmentioning

confidence: 99%

Section: Case Reportsmentioning

confidence: 99%

Clozapine-related EEG changes and seizures: dose and plasma-level relationships

Varma

Bishara

Besag

et al. 2011

Therapeutic Advances in Psychopharmacology

129

109

View full text Add to dashboard Cite

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Section: Introductionmentioning

confidence: 98%

“…We are aware of 12 previous case reports that have demonstrated an association between clozapine and the development of stuttering [Kumar et al 2013;Grover et al 2012;Horga et al 2010;Krishnakanth et al 2008;Abdelmawla and Frost, 2007;Lyall et al 2007;Hallahan et al 2007;Begum, 2005;Bar et al 2004;Duggal et al 2002;Supprian et al 1999;Ebeling et al 1997]. Stuttering is a condition in which the flow or fluency of speech is disrupted by involuntary motor events, resulting in the production of repetitive sounds, syllables and/or fragmented or prolonged words and includes both developmental and neurogenic/iatrogenic subtypes [Krishnakanth et al 2008].…”

Section: Introductionmentioning

confidence: 99%

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Clozapine-induced stuttering: an estimate of prevalence in the west of Ireland

Murphy

Gallagher

Sharma

et al. 2015

Therapeutic Advances in Psychopharmacology

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Objectives: Clozapine is the most effective treatment available for treatment-resistant schizophrenia; however, it is also associated with a large array of adverse effects that limits its tolerability. A number of previous case reports have noted an association between clozapine and stuttering, however the rate of this possible adverse effect is yet to be established. Methods: In this paper, we present six cases of patients treated with clozapine who developed stuttering. Results: Clozapine was associated with stuttering in 0.92% of individuals treated with clozapine in the region. Clozapine-induced stuttering was associated with an increase in treatment dose or with dose titration at initiation of clozapine in five individuals, with dose reduction or slower dose titration associated with a cessation of stuttering in these cases. Conclusions: This is the largest case series to date examining clozapine-induced stuttering and indicates that clozapine-induced stuttering is a relatively common adverse effect that can be managed by a slower titration of clozapine dosage or a modest reduction in dose in most cases.

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