Tolerability of outpatient antipsychotic treatment: 36-month results from the European Schizophrenia Outpatient Health Outcomes (SOHO) study

SOHO is a 3-year, prospective, observational study of schizophrenia patients who started a new antipsychotic in 10 European countries. Cohorts of patients were defined according to the antipsychotic started at baseline: olanzapine, risperidone, quetiapine, amisulpride, clozapine, oral typical and depot typical antipsychotics. Tolerability in terms of rates of extrapyramidal symptoms (EPS), tardive dyskinesia (TD), anticholinergic use, loss of libido/impotence, amenorrhoea/galactorrhoea/gynaecomastia, and weight change was assessed in 4939 patients who started monotherapy. Logistic regression models related medication initiated at study entry to adverse events over follow-up, adjusting by baseline differences among treatment cohorts. Patients taking typical antipsychotics or risperidone were more likely to experience EPS and TD during follow-up than patients taking olanzapine. Patients taking olanzapine were less likely to have loss of libido/impotence during follow-up than patients in the risperidone, amisulpride, clozapine, oral typical and depot typical cohorts. Weight gain occurred in all groups, but was greater with olanzapine. In conclusion, antipsychotics have different tolerability profiles in terms of the adverse events we monitored. Results should be interpreted conservatively due to the observational study design.     

Carmustine implants for the treatment of newly diagnosed high-grade gliomas: a cost-utility analysis

BACKGROUND: High-grade gliomas are aggressive brain tumours that are extremely challenging to treat effectively. The intracranial implantation of carmustine wafers (BCNU-W), which delivers chemotherapy directly to the affected area, may prolong survival in this population. However, no attention has yet been paid to the economic implications of BCNU-W in this setting. OBJECTIVE: To investigate the cost effectiveness of BCNU-W as an adjunct to surgery followed by radiotherapy, compared with surgery plus radiotherapy alone. Newly diagnosed, operable grade III and IV gliomas in a population with a mean age of 55 years were considered. METHODS: A Markov cost-utility model was developed in Microsoft Excel, adopting a UK NHS perspective. Transition probabilities and cost data (year 2004 values) were obtained from published literature or expert opinion. The model incorporated utility values, obtained from members of the public, reflecting the quality of life associated with high-grade glioma. The effects of uncertainty were explored through extensive one-way and probabilistic sensitivity analysis. RESULTS: Surgery with the implantation of BCNU-W followed by radiotherapy costs pound sterling 54 500 per additional QALY gained when compared with surgery plus radiotherapy alone. Probabilistic sensitivity analysis shows a <10% probability that BCNU-W would be considered cost effective at a willingness-to-pay threshold of pound sterling 30 000 per QALY. Although model outputs were sensitive to alterations in several key parameters, the incremental cost effectiveness of the intervention remained above pound sterling 30 000 per QALY in all analyses. CONCLUSION: Compared with usual care for the treatment of newly diagnosed high-grade gliomas, BCNU-W is unlikely to be considered a cost-effective use of healthcare resources when judged by the standards commonly adopted in England and Wales. However, the dreadful prognosis of the condition and the paucity of alternative therapies are additional issues that healthcare commissioners may choose to take into account when considering an adoption decision.     

Three-year antipsychotic effectiveness in the outpatient care of schizophrenia: observational versus randomized studies results.

Antipsychotic discontinuation rates are a powerful indicator of medication effectiveness in schizophrenia. We examined antipsychotic discontinuation in the Schizophrenia Outpatient Health Outcomes (SOHO) study, a 3-year prospective, observational study in outpatients with schizophrenia in 10 European countries. Patients (n=7728) who started antipsychotic monotherapy were analyzed. Medication discontinuation for any cause ranged from 34% and 36% for clozapine and olanzapine, respectively, to 66% for quetiapine. Compared to olanzapine, the risk of treatment discontinuation before 36 months was significantly higher for quetiapine, risperidone, amisulpride, and typical antipsychotics (oral and depot), but similar for clozapine. Longer medication maintenance was associated with being socially active and having a longer time since first treatment contact for schizophrenia, whereas higher symptom severity, treatment with mood stabilizers, substance abuse, having hostile behaviour were associated with lower medication maintenance. Antipsychotic maintenance in SOHO was higher than the results of previous randomized studies.     

Cost effectiveness of imatinib compared with interferon-alpha or hydroxycarbamide for first-line treatment of chronic myeloid leukaemia

OBJECTIVE: To evaluate the cost utility of imatinib compared with interferon (IFN)-alpha or hydroxycarbamide (hydroxyurea) for first-line treatment of chronic myeloid leukaemia. DESIGN AND SETTING: A cost-utility (Markov) model within the setting of the UK NHS and viewed from a health system perspective was adopted. Transition probabilities and relative risks were estimated from published literature. Costs of drug treatment, outpatient care, bone marrow biopsies, radiography, blood transfusions and inpatient care were obtained from the British National Formulary and local hospital databases. Costs (pound, year 2001-03 values) were discounted at 6%. Quality-of-life (QOL) data were obtained from the published literature and discounted at 1.5%. The main outcome measure was cost per QALY gained. Extensive one-way sensitivity analyses were performed along with probabilistic (stochastic) analysis. RESULTS: The incremental cost-effectiveness ratio (ICER) of imatinib, compared with IFNalpha, was pound26,180 per QALY gained (one-way sensitivity analyses ranged from pound19,449 to pound51,870) and compared with hydroxycarbamide was pound86,934 per QALY (one-way sensitivity analyses ranged from pound69,701 to pound147,095) [ pound1=$US1.691=euro1.535 as at 31 December 2002].Based on the probabilistic sensitivity analysis, 50% of the ICERs for imatinib, compared with IFNalpha, fell below a threshold of approximately pound31,000 per QALY gained. Fifty percent of ICERs for imatinib, compared with hydroxycarbamide, fell below approximately pound95,000 per QALY gained. CONCLUSIONS: This model suggests, given its underlying data and assumptions, that imatinib may be moderately cost effective when compared with IFNalpha but considerably less cost effective when compared with hydroxycarbamide. There are, however, many uncertainties due to the lack of long-term data.     

Discriminative stimulus properties in rats of the novel antipsychotic quetiapine

Rats discriminated the novel antipsychotic quetiapine (Seroquel). Full generalization was seen with the novel ("atypical") antipsychotics, clozapine, olanzapine, and risperidone. Generalization was not seen with the older "typical" antipsychotics, haloperidol, chlorpromazine, and loxapine, or with the novel atypical antipsychotic, amisulpride. The pattern of generalization resembled that seen in rats trained to discriminate a low dose (1.25 mg/kg) of clozapine, which dissociates most novel antipsychotics from typical antipsychotics. However, the failure of the novel antipsychotic amisulpride to generalize demonstrates that this bioassay does not detect all novel antipsychotics. These data suggest that the discrimination of antipsychotics such as quetiapine may be of value in the development of novel antipsychotics, although the relationship between the discriminative properties of such drugs and their clinical actions is unclear.     

Cost-effectiveness of atypical antipsychotics for the management of schizophrenia in the UK

ABSTRACT

Objective: To evaluate the cost-effectiveness of atypical antipsychotic treatment sequences for the management of stable schizophrenia in the UK.

Research design and methods: A Markov model was developed to assess the cost per quality-adjusted life year (QALY) gained from 12 alternative treatment sequences each containing two of four atypical antipsychotics (aripiprazole, olanzapine, quetiapine and risperidone), followed by clozapine. The main model parameters were populated with data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study and a recent trial comparing aripiprazole with olanzapine. Patients enter the model with stable schizophrenia and may relapse, discontinue or continue and experience adverse events (AEs), or develop diabetes. Population mortality was adjusted for schizophrenia and diabetes. Utility decrements applied to stable schizophrenia, relapse, diabetes and treatment-related AEs were taken from a direct UK utility elicitation study. Resource use and unit costs were taken from published sources. A time horizon of 10 years was adopted. Results are based on 10,000 probabilistic iterations of the model.

Results: Aripiprazole followed by risperidone produced the greatest number of QALYs, an additional 0.03 compared with risperidone followed by olanzapine, at an incremental cost of £257 (incremental cost/QALY: £9,440). Aripiprazole followed by risperidone had the greatest probability among evaluated sequences of being cost-effective at a threshold of >£10,000/QALY. All other strategies were dominated by at least one of these strategies. The impact of lower pricing for risperidone (based on generic availability) did not impact results.

Conclusions: Modelling the cost-effectiveness of different treatment sequences for stable schizophrenia is appropriate given that patients rarely remain on one treatment for long periods. The treatment sequence aripiprazole followed by risperidone was the most cost-effective option for patients with stable schizophrenia in the UK.     

Economic evaluation of gemcitabine alone and in combination with cisplatin in the treatment of nonsmall cell lung cancer

OBJECTIVE: To evaluate the cost effectiveness of gemcitabine in the treatment of nonsmall cell lung cancer (NSCLC). METHODS: Gemcitabine was compared with best supportive care and gemcitabine/cisplatin was compared with three standard chemotherapies and four other novel chemotherapy combinations. Costs and effectiveness measures were based on resource and outcome data from previously reported clinical trials. All direct costs associated with NSCLC treatment were included and adjusted to year 2000 values. PERSPECTIVE: UK National Health Service. RESULTS: Gemcitabine plus best supportive care was associated with an incremental cost per progression-free life year gained of pound sterling5228 compared with best supportive care alone. In comparison with standard chemotherapies, gemcitabine/cisplatin was associated with an incremental cost per progression-free life year gained of pound sterling1751 versus etoposide/cisplatin and cost per 1-year survival gain of pound sterling5681 versus mitomycin/vinblastine/platinum. Incremental cost per tumour response was pound sterling2032 relative to etoposide/cisplatin, pound sterling5169 relative to mitomycin/ifosfamide/cisplatin and pound sterling6240 relative to mitomycin/vinblastine/platinum. Compared with four novel (newer) combination chemotherapies gemcitabine/ cisplatin showed cost savings in each case, with the same or better outcome. Thus, gemcitabine/cisplatin showed improved cost effectiveness and dominance. Sensitivity analyses showed the results were robust to variations to the values of key parameters. CONCLUSION: Gemcitabine alone or in combination with cisplatin was assessed to be a cost-effective or cost-saving therapy when compared with best supportive care, standard chemotherapy regimens and novel chemotherapy combinations. Chemotherapy regimens containing gemcitabine therefore represent good value for money and efficient use of healthcare resources in the treatment of advanced NSCLC.     

Practical issues with amisulpride in the management of patients with schizophrenia

Amisulpride is an atypical antipsychotic with a significantly greater effect size than first-generation, typical antipsychotics, and efficacy at least similar to that of olanzapine and risperidone in large-scale clinical trials in schizophrenia. Amisulpride provides greater improvement in positive and negative symptoms of schizophrenia, a better long-term outcome than typical antipsychotics, and distinct tolerability advantages over typical antipsychotics, which are reported to cause extrapyramidal symptoms (EPS) in 20-50% of patients. In addition, amisulpride is associated with significantly less weight gain than olanzapine and risperidone, does not increase body mass index, and favourably influences lipid profiles. In many patients with schizophrenia, adverse events impair adherence to treatment, and switching from typical or atypical antipsychotic therapy to amisulpride may be clinically appropriate. Observational drug-utilization studies suggest that many physicians switch to amisulpride because of fewer EPS and/or less weight gain and improved patient adherence. Cross-tapering (over 4 weeks), rather than abrupt cessation of pre-switch treatment, is preferred. Amisulpride has a low risk of drug-drug interactions, and, during cross-tapering, patients can remain on concurrent treatments (e.g. anticholinergics and antiparkinsonian agents) until the effective dosage has been reached. An appropriate amisulpride starting dose is 800 mg/day for patients with acute psychotic exacerbations, 400-800 mg/day for patients with predominantly positive symptoms, and 100-300 mg/day for predominantly negative symptoms. Amisulpride may be particularly suitable for clozapine-augmentation therapy in patients with refractory schizophrenia. Indeed, amisulpride is more effective than quetiapine as augmentation therapy in patients partially responsive to clozapine, and several prospective open-label studies and case series have reported promising results for amisulpride/clozapine combination therapy. In three prospective studies, addition of amisulpride 200-800 mg/day to clozapine significantly reduced mean scores on the Brief Psychiatric Rating Scale (BPRS) total (-33% to -35%), Clinical Global Impression (CGI)-Severity scale (-31%), Positive and Negative Syndrome Scale total (-22%), and Scale for the Assessment of Negative Symptoms (-34%). The proportion of responders (CGI score > or =3 or BPRS improvement >20%) was 71-86%. Retrospective case-series analyses have also reported improved psychopathological state, reduced adverse events, and lower clozapine dosage requirement with use of this combination. The pharmacological and clinical profiles of amisulpride suggest that this agent is a viable clinical option when a change of antipsychotic therapy is required in patients with schizophrenia because of lack of efficacy, adverse events and poor adherence to treatment, or for augmentation of clozapine in treatment-resistant illness.     

The SOHO (Schizophrenia Outpatient Health Outcome) study: implications for the treatment of schizophrenia

The European SOHO (Schizophrenia Outpatient Health Outcome) study is an observational, naturalistic study of the outpatient treatment of schizophrenia. The patient recruitment and assessment began in September 2000 and finished in early 2005. A total of 10 972 adult patients from ten European countries who were initiating or changing antipsychotic medication for the treatment of schizophrenia within the normal course of care have been enrolled. The patients have been followed at regular intervals over the 3-year timeframe of the study. Evaluation includes clinical severity, measured with the Clinical Global Impression (CGI) scale; health-related quality of life; social functioning; and medication tolerability.The 6- and 12-month results have been published so far and have demonstrated that the patients in whom treatment was initiated with olanzapine or clozapine or who were started on more than one antipsychotic of any class at baseline tended to have somewhat greater improvement than patients treated with other atypical or typical antipsychotics, both in terms of symptoms measured with the CGI and quality of life. Numbers of social contacts increased with the treatment, but other aspects of social functioning did not show any significant change.Atypical antipsychotics as a class were associated with a lower frequency of extrapyramidal symptoms (EPS) and anticholinergic use than typical antipsychotics. The frequency of EPS was lowest in the clozapine-, quetiapine- and olanzapine-treated patients, at around 10%. The atypical antipsychotics also conferred a lower risk for tardive dyskinesia than the typical antipsychotics. Weight gain occurred in all treatment cohorts over the first 12 months of treatment and was statistically significantly greater in the patients who started treatment with olanzapine and clozapine. Prolactin- and sexually-related adverse events were frequent at baseline assessment: amenorrhoea was present in around one- third of women, impotence in around 40% of men, and loss of libido in 50% of both male and female patients. Patients treated with olanzapine, clozapine and quetiapine were significantly less likely to have sexual/endocrine-related dysfunctions after 6 months of treatment (the 12-month results of this parameter are yet to be published) than those in the other treatment cohorts (typical antipsychotics, risperidone and amisulpride). Concomitant medication use during the study has been high, ranging from 5% to 29% for anticholinergics, 8% to 23% for antidepressants, 22% to 37% for anxiolytics and 7% to 19% for mood stabilisers, depending on the type of antipsychotic prescribed. Fewer olanzapine-, quetiapine- and clozapine-treated patients used concomitant anticholinergics or anxiolytics/hypnotics.The current results from the SOHO study indicate that differences in effectiveness and tolerability do exist between the antipsychotics. Future results from the study will be published during the coming months and years, and will allow patterns of antipsychotic use in routine clinical practice (including how often and why changes are made) to be determined. This important information is likely to impact on the future use of antipsychotics and will assist clinicians in refining the use of these drugs and improving the outcome of patients to whom they are prescribed.     

Economic evaluation of etoricoxib versus non-selective NSAIDs in the treatment of osteoarthritis and rheumatoid arthritis patients in the UK

INTRODUCTION: The objective of this study was to evaluate the potential economic implications of using etoricoxib versus non-selective NSAID alternatives in the treatment of patients with osteoarthritis (OA) or rheumatoid arthritis (RA) in the UK. STUDY DESIGN: Decision-analytical modelling was used to calculate the expected costs and consequences of the use of etoricoxib compared with non-selective NSAIDs alone, NSAIDs plus proton pump inhibitors (PPIs), NSAIDs plus histamine H2 receptor antagonists and NSAIDs plus misoprostol over a continuous treatment period of 1 year. METHODS: The model considered direct medical costs from the perspective of the UK National Health Service (NHS) and used data from phase IIb and III clinical trials of etoricoxib to determine probabilities of gastrointestinal (GI) events. Model outcomes were defined as resource-consuming GI-related events, including clinically evident gastroduodenal perforations, symptomatic gastroduodenal ulcers, or upper GI bleeding (collectively, PUBs ['perforation, ulcers and/or bleeding']). Resource utilisation and costs (2002 values) for the treatment of OA and RA as well as GI events were based on published literature and information available from UK-specific sources. MAIN OUTCOME MEASURES AND RESULTS: The model suggests that etoricoxib is cost saving compared with non-selective NSAIDs plus PPIs or non-selective NSAIDs plus misoprostol. The model also suggests that etoricoxib is cost effective in terms of the incremental cost per QALY gained for non-selective NSAIDs alone (pound 19,766) and for non-selective NSAIDs plus H2 antagonists (pound 9350). The incremental cost of etoricoxib per PUB avoided was pound 12,446 versus non-selective NSAIDs alone and pound 6438 versus NSAIDs co-prescribed with H2 antagonists. For patients without the presence of specific GI risk factors (history of GI event, corticosteroid use or disability), etoricoxib may be cost effective for patients over age 56 years, assuming a cost-effectiveness threshold of pound 30,000 per QALY gained. Etoricoxib may also be cost effective in patients of all ages who had at least one specific GI risk factor. CONCLUSIONS: The model suggests, with its underlying assumptions and data, that etoricoxib is a cost-effective alternative to therapeutic regimens involving non-selective NSAIDs for OA or RA, from the UK NHS perspective. Etoricoxib may be cost saving and dominant over non-selective NSAIDs used together with a PPI or misoprostol. When compared with non-selective NSAIDs alone or non-selective NSAIDs co-prescribed with H2 antagonists, the incremental cost per QALY gained with use of etoricoxib was within the generally accepted threshold for cost effectiveness (less than pound 30,000 per QALY gained).     

Therapeutic monitoring of new antipsychotic drugs

Typical antipsychotic drugs qualify for therapeutic drug monitoring (TDM) primarily for the following reasons: control of compliance and avoidance of extrapyramidal side effects by keeping chronic exposure to minimal effective blood levels. For the atypical antipsychotic clozapine, drug safety is another reason to use TDM. With regard to the new antipsychotics risperidone, olanzapine, quetiapine, amisulpride, ziprasidone, and aripiprazole, which have been introduced in the clinic during the last few years, the rationale to use TDM is a matter of debate. Positron emission tomography (PET), which enables measurement of the occupancy of dopamine D2 receptors, revealed that receptor occupancy correlated better with plasma concentrations than with doses of the antipsychotics. Regarding plasma levels related to therapeutic effects, optimal concentrations have been established for clozapine (350-600 ng/mL), risperidone (20-60 ng/mL), and olanzapine (20-80 ng/mL) but not for the other new antipsychotics. Studies that included analyses of drug levels in blood reported mean concentrations of 68 ng/mL for quetiapine and 317 ng/mL for amisulpride under therapeutic doses of the antipsychotic drugs. For ziprasidone or aripriprazole, data on therapeutic drug concentrations are so far lacking. In conclusion, evidence is growing that TDM may improve efficacy and safety in patients treated with the new antipsychotic drugs, especially when patients do not respond or develop side effects under therapeutic doses. The few reported investigations, however, need to be confirmed and extended.     

Pharmacological treatment and other predictors of treatment outcomes in previously untreated patients with schizophrenia: results from the European Schizophrenia Outpatient Health Outcomes (SOHO) study

The present study aimed to compare health outcomes and tolerability according to antipsychotic medication (olanzapine, risperidone or an oral typical antipsychotic) after 6 months of treatment in a group of 919 schizophrenic patients who had never previously been treated with antipsychotics. Demographic and clinical predictors of outcome were also identified. Data were extracted from the Schizophrenia Outpatient Health Outcomes (SOHO) study, a prospective, observational study of schizophrenia treatment in 10 European countries. Patients who initiated olanzapine were more likely to have a clinical response than those in the risperidone cohort, and had a greater improvement in quality of life than patients in the risperidone or typical antipsychotic cohorts. High negative and depression symptom scores at baseline and the presence of extrapyramidal symptoms at baseline predicted a worse clinical response, whereas hostile behaviour, paid employment and substance abuse predicted a better clinical outcome. The olanzapine cohort gained more weight than patients in the risperidone cohort, but no significant difference in weight gain was observed between olanzapine and the oral typical antipsychotic cohort. The results should be interpreted conservatively due to the observational study design.     

Early changes of plasma lipids during treatment with atypical antipsychotics

Metabolic side effects have been found earlier during treatment with second-generation antipsychotics. Among those disturbances serum lipids are less investigated. We conducted a prospective, open study in schizophrenia patients in order to compare body weight and serum lipids during treatment with amisulpride, ziprasidone, clozapine or olanzapine over a period of 4 weeks. Body mass index, total cholesterol and triglycerides increased in patients treated with clozapine and olanzapine whereas high-density lipoprotein cholesterol decreased in those patients. In patients treated with amisulpride or ziprasidone, we found a decrease in body mass index and total cholesterol whereas high-density lipoprotein cholesterol increased. Our results indicate that treatment with ziprasidone and amisulpride is more favourable than treatment with clozapine and olanzapine with respect to the risk to induce weight gain and hyperlipidaemia. These results are important with regard to the increased risk for cardiovascular complications in patients with schizophrenia.     

A systematic review of the use of atypical antipsychotics in autism

Conventional antipsychotic medication is commonly prescribed to patients with autistic spectrum disorder. However, a high incidence of severe adverse reactions highlights the need to find more favourable treatments. Atypical antipsychotics may combine efficacy in ameliorating some autistic symptoms with a lower incidence of some adverse reactions. This article reviews the use of atypical antipsychotics in autistic disorder, with particular focus on behaviour, cognition and physical well-being. Thirteen studies using risperidone, three using olanzapine, one using clozapine, one using amisulpride and one using quetiapine were identified. Few firm conclusions can be drawn due to the limitations of the studies; however, there is an indication that risperidone may be effective in reducing hyperactivity, aggression and repetitive behaviours, often without inducing severe adverse reactions. Olanzapine and clozapine may also be effective; however, there is little evidence for using amisulpride or quetiapine in this population. Randomized trials are required to clarify the effectiveness of these agents.     

Atypical antipsychotic drugs: current issues of safety and efficacy in the management of schizophrenia

This review focuses on the comparative safety and efficacy profile of nine atypical antipsychotic drugs (amisulpride, aripiprazole, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone and zotepine), which may ultimately affect the therapeutic options available for patients with schizophrenia. These antipsychotic compounds differ markedly in their potential to impact a number of quality-of-life measures. Furthermore, their differential effects on anxiety disorders, treatment-resistant depressive illness, cognitive functions and manic disorders may influence the selection of atypical antipsychotics for conditions associated with schizophrenia. The possible relevance of these parameters in evaluating the risk/benefit equation and probable involvement of varying receptor mechanisms is also discussed.     

Cost-Effectiveness of Treating Upper Limb Spasticity Due to Stroke with Botulinum Toxin Type A: Results from the Botulinum Toxin for the Upper Limb after Stroke (BoTULS) Trial

Stroke imposes significant burdens on health services and society, and as such there is a growing need to assess the cost-effectiveness of stroke treatment to ensure maximum benefit is derived from limited resources. This study compared the cost-effectiveness of treating post-stroke upper limb spasticity with botulinum toxin type A plus an upper limb therapy programme against the therapy programme alone. Data on resource use and health outcomes were prospectively collected for 333 patients with post-stroke upper limb spasticity taking part in a randomized trial and combined to estimate the incremental cost per quality adjusted life year (QALY) gained of botulinum toxin type A plus therapy relative to therapy alone. The base case incremental cost-effectiveness ratio (ICER) of botulinum toxin type A plus therapy was £93,500 per QALY gained. The probability of botulinum toxin type A plus therapy being cost-effective at the England and Wales cost-effectiveness threshold value of £20,000 per QALY was 0.36. The point estimates of the ICER remained above £20,000 per QALY for a range of sensitivity analyses, and the probability of botulinum toxin type A plus therapy being cost-effective at the threshold value did not exceed 0.39, regardless of the assumptions made.     

Clozapine: an appraisal of its pharmacoeconomic benefits in the treatment of schizophrenia

Clozapine, an antipsychotic agent with relatively weak central antidopaminergic activity, displays atypical pharmacological and clinical properties vis-a-vis the classic antipsychotics. Thus, clozapine is effective against both the positive and negative symptoms of schizophrenia and has a low propensity to cause extrapyramidal effects. Furthermore, clozapine is effective in a substantial proportion (up to 60%) of patients who are refractory to or intolerant of standard antipsychotic therapy. Despite its promising therapeutic potential, the relatively high incidence of clozapine-induced agranulocytosis (approximately 1% of patients) and the associated need for regular haematological monitoring currently restricts the drug's use to the treatment of chronic and severe schizophrenia refractory to standard antipsychotic therapy, and to those patients unable to tolerate such therapy. In the US, the current wholesale price of clozapine (exclusive of monitoring) is $US2.85 per 100mg tablet, amounting to $US4160 annually (1992 dollars) at the most commonly prescribed dose of 400 mg/day ($US2.40 per tablet and $US3510 annually to state programmes through Medicaid reimbursement legislation). In the UK, the annual cost of clozapine (at the average dose of 300 mg/day), inclusive of blood monitoring, is 1806 British pounds sterling (1992 pounds). Although the acquisition cost of clozapine is high in comparison with that of standard antipsychotics, preliminary cost-effectiveness estimates in patients with treatment-resistant schizophrenia suggest that the clinical benefits of the drug (viz. improved psychopathology, social functioning and quality of life) may confer medium to long term economic benefits, primarily by reducing the need for psychiatric hospital services. This effect is most likely to be seen on long term ( greater than or equal to 2 years) maintenance therapy with clozapine. Savings in hospital costs are, however, likely to be offset, at least initially, by increased reliance on outpatient services, and clozapine may therefore confer additional economic costs during the first year or so of treatment. In the longer term, however, the initial cost investment may be recouped in the form of savings to psychiatric institutions and insurers.     

Modelling the cost effectiveness of cholinesterase inhibitors in the management of mild to moderately severe Alzheimer's disease

OBJECTIVE: To estimate the cost effectiveness (from the UK NHS and personal social services perspective) of the cholinesterase inhibitors donepezil, rivastigmine and galantamine compared with usual care in the treatment of mild to moderately severe Alzheimer's disease. Patients had a mean age of 74 years, a mean disease duration of 1 year and a mean Alzheimer's disease assessment scale-cognitive subscale score of 24. METHODS: A pharmacoeconomic model was used to predict long-term outcomes over a 5-year time horizon and to estimate the cost effectiveness of cholinesterase inhibitors for the management of Alzheimer's disease. The model structure is informed by a systematic review of the literature on the clinical and cost effectiveness of cholinesterase inhibitors and a review of the literature on the costs and outcomes associated with treatment for Alzheimer's disease. The main outcome measure used was the cost per quality-adjusted life-year (QALY) gained. All healthcare costs (excluding cholinesterase inhibitor costs) were indexed to pounds sterling (2003 values). Drug costs are 2005 values. Multivariate probabilistic sensitivity analysis and scenario analysis were undertaken to assess uncertainty in the results. RESULTS: The clinical benefits on cognition from treatment with cholinesterase inhibitors resulted in an incremental cost per QALY gained ranging from 53,780 pounds sterling to 74,735 pounds sterling, over 5 years (vs usual care). Uncertainty analysis suggests that the probability of any of these treatments having an incremental cost per QALY of < 30,000 pounds sterling is < 21%. The key determinants of cost effectiveness were the effectiveness of treatment, the mean treatment cost and the cost savings associated with an expected delay in disease progression. CONCLUSIONS: Results presented in this paper suggest that the use of cholinesterase inhibitors may not be a cost-effective use of NHS resources. Guidance from the National Institute for Health and Clinical Effectiveness (NICE) in the UK on their judgements surrounding the acceptability of technologies as an effective use of resources, indicates there would need to be special reasons for accepting cholinesterase inhibitors as a cost-effective use of NHS resources.