Given increasing reports about the frequency in off-label prescribing of quetiapine, particularly for populations at risk of disproportionate side-effects (young and elderly),1,2 the authors examined community pharmacy dispensing records for Canterbury District Health Board (Population 543,820)3 in the month of January 2018. These data were analysed on Tableaux™. Four thousand three hundred and thirty-two (4,332) patients were dispensed a prescription of quetiapine; 1,478 received risperidone; 1,311 olanzapine; 508 haloperidol; 411 clozapine; 342 aripiprazole; 161 paliperidone; 120 chlorpromazine and 26 ziprasidone. The proportion of patients’ dispensed quetiapine (4,332) was essentially the same as all the other antipsychotics studied (4,357).

The data are particularly compelling when compared to a recent survey the authors completed looking at 200 consecutive patients with a diagnosis of schizophrenia discharged from inpatient psychiatric care in Canterbury between April 2017 and March 2018. In this survey only 1% of patients (2/200) were discharged on quetiapine monotherapy and a further 2.5% (5/200) patients were on a combination of regular antipsychotics that included quetiapine.

Quetiapine is only licensed for schizophrenia and bipolar affective disorder in New Zealand.4 Quetiapine does not have a license for children and adolescents under the age of 18 nor does it have a license for dementia-related psychoses in the elderly.4

Given the very common prescription of quetiapine and limited potential for licensed indications, we infer that most of the prescriptions are for off-label use. Commonly cited examples in the literature for this include augmentation in the treatment of depression, night sedation and as an anxiolytic.5,6 Quetiapine is associated with metabolic syndrome, constipation, QTc interval prolongation, has misuse and abuse potential and also overdose potential.2,7,8 Given these risks, patients should be fully informed of the expected risks and benefits of treatment, and the limited evidence base for off-label prescribing. Informed consent should be sought.

Of note, night sedation medications are frequently dispensed in community pharmacy. In January 2018, 7,274 patients were dispensed a prescription for zopiclone, 1,235 received triazolam, 1,112 received temazepam and 102 received nitrazepam. Insomnia is a common problem and quetiapine is sometime viewed as a “safer” alternative than zopiclone or benzodiazepines as a hypnotic.9 There is insufficient evidence for this and should wherever possible be avoided. Working to counter patients’ increased expectations of a prescription, highlighting the benefits of sleep hygiene, the risks of substance impaired driving and only prescribing short “one off” courses of hypnotics maybe some of the ways to reduce the numbers of patients requesting hypnotics or quetiapine for insomnia.

One of the limitations of this letter is that we used a dispensing database to obtain the numbers of patients that were dispensed antipsychotics by community pharmacies in Canterbury. The data only related to numbers of patients that were dispensed medications. Doses and indications were not available. Specific information on doses and indications would be valuable in clarifying the extent and types of off-label prescribing of quetiapine.

In summary, this survey adds evidence that everyday prescription of quetiapine does not appear to be in keeping with its use as an antipsychotic, and widespread off-label prescribing is common and not without short- and long-term risks.

‍

Given increasing reports about the frequency in off-label prescribing of quetiapine, particularly for populations at risk of disproportionate side-effects (young and elderly),1,2 the authors examined community pharmacy dispensing records for Canterbury District Health Board (Population 543,820)3 in the month of January 2018. These data were analysed on Tableaux™. Four thousand three hundred and thirty-two (4,332) patients were dispensed a prescription of quetiapine; 1,478 received risperidone; 1,311 olanzapine; 508 haloperidol; 411 clozapine; 342 aripiprazole; 161 paliperidone; 120 chlorpromazine and 26 ziprasidone. The proportion of patients’ dispensed quetiapine (4,332) was essentially the same as all the other antipsychotics studied (4,357).

The data are particularly compelling when compared to a recent survey the authors completed looking at 200 consecutive patients with a diagnosis of schizophrenia discharged from inpatient psychiatric care in Canterbury between April 2017 and March 2018. In this survey only 1% of patients (2/200) were discharged on quetiapine monotherapy and a further 2.5% (5/200) patients were on a combination of regular antipsychotics that included quetiapine.

Quetiapine is only licensed for schizophrenia and bipolar affective disorder in New Zealand.4 Quetiapine does not have a license for children and adolescents under the age of 18 nor does it have a license for dementia-related psychoses in the elderly.4

Given the very common prescription of quetiapine and limited potential for licensed indications, we infer that most of the prescriptions are for off-label use. Commonly cited examples in the literature for this include augmentation in the treatment of depression, night sedation and as an anxiolytic.5,6 Quetiapine is associated with metabolic syndrome, constipation, QTc interval prolongation, has misuse and abuse potential and also overdose potential.2,7,8 Given these risks, patients should be fully informed of the expected risks and benefits of treatment, and the limited evidence base for off-label prescribing. Informed consent should be sought.

Of note, night sedation medications are frequently dispensed in community pharmacy. In January 2018, 7,274 patients were dispensed a prescription for zopiclone, 1,235 received triazolam, 1,112 received temazepam and 102 received nitrazepam. Insomnia is a common problem and quetiapine is sometime viewed as a “safer” alternative than zopiclone or benzodiazepines as a hypnotic.9 There is insufficient evidence for this and should wherever possible be avoided. Working to counter patients’ increased expectations of a prescription, highlighting the benefits of sleep hygiene, the risks of substance impaired driving and only prescribing short “one off” courses of hypnotics maybe some of the ways to reduce the numbers of patients requesting hypnotics or quetiapine for insomnia.

One of the limitations of this letter is that we used a dispensing database to obtain the numbers of patients that were dispensed antipsychotics by community pharmacies in Canterbury. The data only related to numbers of patients that were dispensed medications. Doses and indications were not available. Specific information on doses and indications would be valuable in clarifying the extent and types of off-label prescribing of quetiapine.

In summary, this survey adds evidence that everyday prescription of quetiapine does not appear to be in keeping with its use as an antipsychotic, and widespread off-label prescribing is common and not without short- and long-term risks.

‍