This quiz feedback provides an opportunity to revisit the BPJ 40 (November, 2011) article "Prescribing ATYPICAL ANTIPSYCHOTICS in general practice"

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Antipsychotics are indicated for the treatment of schizophrenia and related disorders.

In some circumstances, risperidone may be considered to manage the behavioural and psychological symptoms associated with dementia, but only after behavioural and lifestyle interventions have been trialled. Antipsychotics are increasingly being used off-label for conditions such as anxiety, insomnia and post-traumatic stress disorder.

Common, dose related adverse effects of antipsychotics include sedation, anticholinergic effects, e.g. dry mouth, constipation, blurred vision and postural hypotension/dizziness. Most adverse effects are common to all types of antipsychotics, but occur to varying degrees. Clozapine, olanzapine and quetiapine are particularly associated with sedation. Postural hypotension is especially seen with clozapine, risperidone and quetiapine and dry mouth (and other anticholinergic effects) with clozapine and olanzapine.

Atypical antipsychotics are associated with metabolic adverse effects, e.g. weight gain, dyslipidaemia and hyperglycaemia (along with the development of type 2 diabetes) – particularly olanzapine and clozapine. People taking these medicines often experience a stimulation of appetite and report that they “always feel hungry”. Weight gain can be substantial – a gain of 2 kg in two weeks should prompt a medicine review. Atypical antipsychotics are generally considered to cause fewer extrapyramidal adverse effects than typical antipsychotics.

The early detection and prompt treatment of a first episode of schizophrenia is essential and can improve health outcomes and possibly even the progression of the illness. Both typical and atypical antipsychotics are used in the treatment of schizophrenia. Atypical medicines are currently recommended as first-line treatment in Australasian guidelines, however, this recommendation has been recently challenged due to the concern that metabolic adverse effects associated with atypical antipsychotics are more problematic in the longer term. Therefore, choice of medicine should be tailored to individual patient circumstances rather than a “one size fits all” approach (such as using quetiapine for everyone). Clozapine is recommended in cases of treatment resistance, after the patient has trialled at least two other antipsychotics. Pharmacological treatments for schizophrenia should always be used in conjunction with comprehensive psychosocial interventions.

Blood tests (white cell count and absolute neutrophil count) are required:

• Ten days before commencing treatment
• Each week of the first 18 weeks of treatment
• Every four weeks during treatment thereafter
• Four weeks after discontinuation
• After discontinuation due to abnormal blood tests, until levels return to normal

Non-pharmacological treatment is recommended first-line for the behavioural and psychological symptoms of dementia (BPSD) including aggressiveness (verbal outburst, physical violence), activity disturbance (agitation, wandering) and psychotic symptoms. Patients with these symptoms may respond to interventions such as improvements to the environment.

In some severe cases, antipsychotics can be used to help manage BPSD - risperidone is the only atypical antipsychotic officially indicated for BPSD. If the decision is made to prescribe, then initial doses should be reduced to half the adult dose or less, taking into account factors such as the patient’s weight, co-morbidities and concomitant medication. Antipsychotic treatment is not effective for symptoms such as wandering, social withdrawal, shouting, pacing, touching, cognitive defects and incontinence.

Off-label prescribing is legal in most countries, including New Zealand, therefore a prescriber can make a clinical decision to prescribe atypical antipsychotics “off-label” for indications such as severe anxiety. However, the prescriber needs to carefully weigh up the risks and benefits and consider other appropriate medicines (or non-pharmacological options) first as well as document the decision and related discussion in the patient’s notes.

SSRIs are a first-line treatment for generalised anxiety disorder. There is some evidence that quetiapine may be also effective treatment, but due to its adverse effects, it should only be considered for the short-term treatment of anxiety if all other appropriate pharmacological or psychological treatments have been trialled and were ineffective.

SSRIs are also a first-line treatment for post-traumatic stress disorder. There is a lack of evidence to support the use of quetiapine for this indication. Nor is quetiapine indicated for the treatment of insomnia in the absence of a psychiatric disorder.

The weight gain in people using olanzapine can be 1 to 3 kg greater than that associated with other atypical antipsychotics such as risperidone, with teenagers being more likely to gain weight and to gain more weight than adults. Weight, waist circumference and BMI should be monitored.

When prescribing olanzapine the clinician should be particularly aware of the metabolic adverse effects including weight gain, raised lipid levels (increase in triglycerides, LDL and total cholesterol, decrease in HDL cholesterol), impaired glucose tolerance and new-onset diabetes. Olanzapine has been associated with a greater risk of new-onset diabetes compared with the other atypical antipsychotics and it is recommended that it should be avoided in people with risk factors for diabetes, e.g. obesity or family history. If olanzapine is used, Hba1c or fasting glucose levels should be monitored before and periodically during treatment.