Polypharmacy and high-dose antipsychotic regimes in the community

Aims and method To determine the pattern of psychotropic prescribing 
in a group of people with psychosis who were living in the community under 
community mental health team (CMHT) care. Case-note entries over the previous 
12 months were examined. Results Only a third of individuals were on one psychotropic 
medication. Atypical antipsychotics were prescribed to 80.6%. Polypharmacy was 
common. A third of people were taking three or more psychotropic drugs and 
13.7% were on high-dose regimes, mostly involving two atypical 
antipsychotics. Clinical implications The use of atypicals has not eliminated 
polypharmacy or high-dose antipsychotic regimes. Clinicians need to be aware 
of this long-standing problem.


Method
Most previous studies of antipsychotic polypharmacy and high-dosage regimes have been hospital based. Our study concerns individuals living in the community. The study was conducted within five community mental health teams (CMHTs) in urban and rural parts of North East Wales. On average each CMHT had 274 patients. Data were gathered retrospectively. Case-note entries for the previous 12 months (September 2006 to August 2007) were examined. All prescriptions and dosages of psychotropic medications were recorded.
The aim of the study was to observe the pattern of prescribing of psychotropic drugs and to determine the extent of high dose and polypharmacy regimes for individuals with schizophrenia and related disorders and bipolar disorders who are under the care of a CMHT. Although the use of some medications may have been transitional, we did not attempt to determine the rationale behind such regimes.
High-dose antipsychotic use was determined using chlorpromazine equivalents (CPZeq) 8,9 and aggregated percentages of BNF maximum doses. Anyone receiving over 1000 mg of CPZep or above 100% aggregated BNF percentage was considered to be on a high dose. The percentage calculation alone was used for risperidone longacting injection and zotepine.

Results
The Aims and method To determine the pattern of psychotropic prescribing in a group of people with psychosis who were living in the community under community mental health team (CMHT) care. Case-note entries over the previous 12 months were examined.
Results Only a third of individuals were on one psychotropic medication. Atypical antipsychotics were prescribed to 80.6%. Polypharmacy was common. A third of people were taking three or more psychotropic drugs and 13.7% were on high-dose regimes, mostly involving two atypical antipsychotics.
Clinical implications The use of atypicals has not eliminated polypharmacy or highdose antipsychotic regimes. Clinicians need to be aware of this long-standing problem.
Declaration of interest T.E.T. accepted sponsorship to attend conferences from Janssen-Cilag, Eli Lilly, Bristol-Myers Squibb and Otsuka Pharmaceuticals. R.P. has accepted speakers' fees from Lundbeck, Eli Lilly and Pfizer, and accepted sponsorship to attend conferences from Wyeth, Astra Zeneca and Eli Lilly.

Polypharmacy
Only 32.7% of individuals were taking one antipsychotic medication alone. The remaining 67.3% were taking a combination of psychotropic drugs, i.e. an antipsychotic alongside an antidepressant, mood stabiliser, benzodiazepine, antimuscarinic or hypnotic. Overall, 37% were taking two psychotropics, 16.1% were on three, 10.4% on four, 3.3% were on five. One patient (0.5%) was taking six psychotropic drugs (Fig. 1). Nearly a third of people were receiving three or more psychotropic medications.

High-dose antipsychotic utilisation
Twenty-nine (13.7%) individuals were on a high-dose antipsychotic regime. Calculation of CPZep identified 13 people and 26 were identified by the aggregated percentage method.
As a group, all 29 individuals on high-dose antipsychotics were on atypicals, with the exception of one person who was taking a typical-atypical combination. Twenty individuals were taking a combination of two atypical antipsychotics, with only nine receiving one atypical medication. Seventeen of the high-dose regimes had been started within the past 12 months, and twelve of these regimes had been in place for over a year.
High-dose antipsychotic regimes were associated with taking two antipsychotics (P50.0001, Fisher's exact test); receiving atypicals (P50.003, Fisher's exact test); with being on antidepressants (P50.015, Fisher's exact test); and with receiving three psychotropics or more (P50.0001, Fisher's exact test) ( Table 1). There was no association between high doses and gender (P50.067, Fisher's exact test), although there was a trend towards being male. No association was observed between the use of mood stabilisers, benzodiazepines or antimuscarinics and highdose antipsychotic prescribing.

Other psychotropics
Antidepressants were being prescribed to 43.6% of the individuals, with 3.8% receiving two antidepressants. However, 54.5% of people had received antidepressants at some time in the previous 12 months. Mood stabilisers were prescribed to 14.7% of individuals. Lithium carbonate was prescribed to 5.7% of people and sodium valproate was prescribed to 6.1%. Twenty-two (10.4%) of individuals were receiving benzodiazepines, mostly commonly diazepam. Thirty-seven (17.5%) were receiving antimuscarinic drugs and fifteen (7.1%) were receiving hypnotics, mainly zopiclone.

Discussion
We observed a high rate of atypical antipsychotic use in CMHT patients. Our study shows that polypharmacy remains common, even among individuals who are settled and are resident in the community. Irrational regimes, such as atypical-typical antipsychotic combinations, were uncommon compared with previous in-patient studies. 7

ORIGINAL PAPERS
Tungaraza et al Polypharmacy and high-dose antipsychotics in the community  In accordance with National Institute for Health and Clinical Excellence (NICE) guidance, 5 atypical anti-psychotics are recommended to be the first-line drug treatment for psychosis. Recent findings, 10,11 although suggesting that they are no more effective and no better tolerated than typical antipsychotics, were probably too recent to have altered prescribing. The routine use of atypicals does not seem to have eliminated high-dose antipsychotic regimes, prescribed here for 13.7% of individuals. Our findings confirm the association between polypharmacy and highdose antipsychotic regimes. Two-thirds of high-dose regimes involved two atypicals in contrast to earlier findings where high-dose typical-atypical combinations were more common. 12 Almost a half of high-dose antipsychotic regimes had been followed for more than a year. Most of these individuals were on more than one antipsychotic and they were more likely to be receiving three or more psychotropics. It is possible that the prescribing clinicians were not aware that they were pursuing a high-dose regime. Persistent high-dose regimes carry risks for patients. 13 Prescribers should be aware of the risk of high dosage when they prescribe drug combinations.
Our study has some limitations. It is based on retrospective examination of case notes. However, the quality of documentation was good. Letters to the general practitioner followed each consultation. Both the CPZep and the BNF percentage methods of ascertaining high-dose regimes are imperfect, particularly as they aggregate doses of drugs with different mechanisms of action. However, they are well recognised and accepted methods that have been used elsewhere. 6,12 Our study shows that people in the community are routinely exposed to polypharmacy and high-dose antipsychotic regimes. This is in contrast with guidelines and advice that have been available for many years suggesting that such regimes are unnecessary and potentially hazardous. Although attempts have been made to understand this phenomenon, 4,14,15 little is understood about psychiatrists' prescribing behaviour and the reasons for it. In the light of the emergence of a new group of non-medical prescribers, there is an urgent need to understand how and why suboptimal prescribing occurs.