24 - References

References

822 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 10 References

1. Boot E, et al. Updated clinical practice recommendations for managing adults with 22q11.2 deletion syndrome. Genet Med 2023; 25:100344.
2. McDonald-­McGinn DM, et al. 22q11.2 deletion syndrome. Nat Rev Dis Primers 2015; 1:15071.
3. Bayat M, et al. Neurological manifestation of 22q11.2 deletion syndrome. Neurol Sci 2022; 43:1695–1700.
4. Mosheva M, et al. Effectiveness and side effects of psychopharmacotherapy in individuals with 22q11.2 deletion syndrome with comorbid psychiatric disorders: a systematic review. Eur Child Adolesc Psychiatry 2020; 29:1035–1048.
5. Fung WL, et al. Practical guidelines for managing adults with 22q11.2 deletion syndrome. Genet Med 2015; 17:599–609.
6. Tanham M, et al. The effectiveness and tolerability of pharmacotherapy for psychosis in 22q11.2 deletion syndrome: a systematic review. Aust NZ J Psychiatry 2024; 58:393–403.
7. Van L, et al. Mental health in adults with 22q11. 2 deletion syndrome. In: McDonald-­McGinn DM, ed. The Chromosome 22q11. 2 Deletion Syndrome. London: Academic Press; 2022:322–337.
8. Baker K, et al. Psychiatric illness. Consensus document on 22q11 deletion syndrome (22q11DS) MaxAppeal. 2017; https://www.maxappeal.org. uk/library-­consensus-­document.
9. Chung LM, et al. Safety of stimulant medications for attention deficit hyperactivity disorder in paediatric congenital heart disease. J Paediatr Child Health 2023; 59:580–588. Psychiatric disorder Treatments Schizophrenia Standard treatment protocols are generally recommended.1,5 People with 22q11.2DS may be more susceptible to seizures and EPSEs with antipsychotics.7,8 EPSEs must be distinguished from motor problems that may be a direct effect of the 22q11.2DS (diagnosis of Parkinson’s disease may be delayed if misattributed to antipsychotics).7 Specialist neurological opinion and neuroimaging have been recommended to distinguish Parkinson’s disease from antipsychotic-­induced parkinsonism.6 There is a significantly elevated risk of obesity in 22q11.2DS so metabolic adverse effects should be closely monitored.12 Those with cardiac abnormalities have an increased risk of QTc prolongation.8 Close ECG monitoring is recommended.8 Antipsychotics with a low effect on the QT interval are preferred8 (note that hypocalcaemia can also prolong the QT interval7). Low starting doses and slow dose titrations are recommended.8 Case reports have described the successful use of various antipsychotics, with remission of psychosis in 41% of published reports.6 Treatment resistance has been described in 19% of case series and 8% of case reports (although treatment failure was due to adverse effects rather than inefficacy in some).6 Clozapine was found to be effective in one retrospective study of 20 patients with 22q11.2DS.4 Compared with matched controls, lower doses were needed (a median of 250mg/day vs 450mg/ day). However, half of the 22q11.2DS group experienced at least one serious adverse effect from clozapine, primarily seizures, but also myocarditis and neutropenia. Several case reports further support the efficacy of clozapine at low doses (median of 200mg/day) for people with 22q11.2DS, while highlighting the risk of both seizures (generalised or myoclonic) and thrombocytopenia.12 Overall, clozapine appears to have demonstrable efficacy at lower than usual doses, but the risk of rare serious adverse events appears to be relatively high.4 Adjunctive anticonvulsants should be considered12 to mitigate the increased seizure risk when prescribing clozapine.1 Several authors advocate the use of lower starting doses and slower titrations.6 Seizures with other antipsychotics: investigate low calcium and magnesium levels in all cases and ensure adequate treatment.13 Adjunctive anticonvulsants can be considered1 although they should not be prescribed routinely as many do not experience seizures.6 Other agents: drugs that act directly against catecholamine excess may also be effective. Metyrosine, used as a monotherapy or as an adjunctive agent, was found to be effective in 22 of 29 patients in one study.14 An additional positive case report has been published15 but there are no further recent studies. There is a single case study where methyldopa was used successfully.16 DS, deletion syndrome; EPSEs, extrapyramidal side effects; OCD, obsessive compulsive disorder. Table 10.7  (Continued)

Drug treatment of psychiatric symptoms in the context of other conditions CHAPTER 10 10. Maeder J, et al. Selective effects of methylphenidate on attention and inhibition in 22q11.2 deletion syndrome: results from a clinical trial. Int J Neuropsychopharmacol 2022; 25:215–225. 11. Gothelf D, et  al. Obsessive-­compulsive disorder in patients with velocardiofacial (22q11 deletion) syndrome. Am J Med Genet B Neuropsychiatr Genet 2004; 126b:99–105. 12. De Boer J, et al. Adverse effects of antipsychotic medication in patients with 22q11.2 deletion syndrome: a systematic review. Am J Med Genet A 2019; 179:2292–2306. 13. Bassett AS, et al. Practical guidelines for managing patients with 22q11.2 deletion syndrome. J Pediatr 2011; 159:332–339. 14. Faedda GL, et al. 4.19 Treatment of velo-­cardio-­facial syndrome-­related psychosis with metyrosine. J Am Acad Child Adolesc Psychiatry 2016; 55:S169. 15. Engebretsen MH, et  al. Metyrosine treatment in a woman with chromosome 22q11.2 deletion syndrome and psychosis: a case study. Int J Dev Disabil 2019; 65:116–121. 16. O’Hanlon JF, et al. Replacement of antipsychotic and antiepileptic medication by L-­alpha-­methyldopa in a woman with velocardiofacial syndrome. Int Clin Psychopharmacol 2003; 18:117–119.