Clozapine-induced gastroesophageal rumination in 22q11.2 Deletion Syndrome. A case report on gastroesophageal side effects management without renouncing clozapine's effectiveness

Efficacy and safety of clozapine in treatment-resistant psychotic patients with DiGeorge syndrome (22q11.2 deletion syndrome): a case series

Neuropsychiatric disorders are common manifestations in 22q11.2 deletion syndrome (22q11.2DS-DiGeorge Syndrome). Although many patients with 22q11.2DS receive antipsychotic treatment for psychotic disorders, little is known about the safety and tolerability of antipsychotics in 22q11.2DS and resistant psychosis. The aim of this case series is to describe the effectiveness as well as safety and tolerability profile coming from the real-world observation of three clinical cases affected by 22q11.2DS and treatment-resistant psychosis. We administered the following tests: the Columbia Suicide Severity Rating Scale, the Hamilton Rating Scale for Anxiety, the Positive and Negative Severity Scale, the Clinical Global Impression-Severity Scale, the Yale-Brown Obsessive-Compulsive Scale, the Beck Depression Inventory and the Beck Hopelessness Scale. All these questionnaires were administered at the first visit (T0), and then 3 (T1) 6 (T2) and 12 months after (T3). We observed a clinical improvement that remained stable at 12 months. Furthermore, in our patients, the clinical effectiveness was achieved with a very low dose of clozapine (<150 mg/day) concerning the standard dose used in idiopathic schizophrenia (>300 mg/day to 600 mg/day).

The effectiveness and tolerability of pharmacotherapy for psychosis in 22q11.2 Deletion Syndrome: A systematic review

OBJECTIVE

The 22q11.2 Deletion Syndrome (22q11.2DS) is the most common microdeletion in humans with over 180 phenotypic expressions. Approximately 30-40% of affected individuals will develop psychosis and 25% meet the criteria for schizophrenia. Despite this, pharmacotherapy for managing psychosis in 22q11.2DS is poorly understood and 22q11.2DS psychosis is frequently labelled as treatment resistant. The objectives of this paper are to evaluate the effectiveness and tolerability of pharmacotherapy for 22q11.2DS psychosis and evaluate the evidence for treatment resistance.

METHOD

A systematic search was performed using CINAHL, The Cochrane Library (Cochrane Database of Systematic Reviews; Cochrane Central Register of Controlled Trials and Cochrane Clinical Answers), EMBASE, PsycINFO, PubMed, Scopus and Web of Science Core Collection from inception to December 2022. It yielded 39 case reports, 6 case series and 1 retrospective study which met the inclusion criteria.

RESULTS

Based on the current literature, individuals with 22q11.2DS psychosis experience a greater rate of medical co-morbidities such as cardiac arrhythmias, seizures and movement disorders, which complicate pharmacotherapy. Poor tolerability rather than poor clinical response motivates the switching of antipsychotics, which may explain the labelling of treatment resistance in the literature.

CONCLUSION

There are insufficient data to recommend a single antipsychotic for 22q11.2DS psychosis. Nonetheless, with proactive management of co-morbidities, antipsychotic medication in 22q11.2DS psychosis is an effective treatment commonly resulting in improvement in quality of life.

Clozapine Use in 22q11.2 Deletion Syndrome: A Systematic Review of the Literature

BACKGROUND

22q11.2 deletion syndrome confers significant risk for the development of schizophrenia. While current recommendations regarding the management of psychotic symptoms in affected individuals are generally in keeping with treatment guidelines for general schizophrenia populations, evidence for the use of clozapine has come from case reports and retrospective observational data. As no reviews on the topic currently exist, a systematic review of clozapine use in 22q11.2 deletion syndrome was completed.

METHODS

In November 2023, a literature search was completed using both PubMed and Scopus to identify English-language articles that reported the use of clozapine in humans with 22q11.2 deletion syndrome.

RESULTS

Twenty-six articles describing 57 individuals were deemed eligible for inclusion. Most individuals had a diagnosis of treatment-resistant schizophrenia. Where reported, the mean or median dose of clozapine was relatively low, and the majority of individuals exhibited a good response (approximately 65.5% across individual case reports/series). While seizures were unsurprisingly the most commonly reported serious adverse effect, the majority of individuals were able to remain on (or be restarted on) clozapine by having their dose decreased and/or by adding an anticonvulsant (most commonly valproate).

CONCLUSIONS

This review reaffirms that individuals with 22q11.2 deletion syndrome may benefit from clozapine therapy even at a low dose, assuming they meet criteria for treatment-resistant schizophrenia and provided no contraindications exist. However, given the increased incidence of seizures in 22q11.2 deletion syndrome, the use of prophylactic anticonvulsant therapy should be considered, and hypoparathyroidism/hypocalcemia screened for and corrected before the initiation of clozapine. It is also recommended that clozapine blood levels be monitored.