Topical bimatoprost: a review of its use in open-angle glaucoma and ocular hypertension

Bimatoprost, a synthetic prostamide analogue, is a new ocular hypotensive agent indicated for the second-line treatment of open-angle glaucoma and ocular hypertension. The drug is formulated as a 0.03% ophthalmic solution. Bimatoprost lowers intraocular pressure (IOP) by increasing aqueous humour outflow. When applied topically once daily in patients with ocular hypertension or glaucoma, bimatoprost 0.03% significantly reduced IOP. Mean IOP was reduced by approximately 7.5 to 9.2mm Hg 12 hours after drug administration in randomised clinical trials. The reduction in IOP was maintained throughout the 24-hour dosage interval. Once-daily treatment with bimatoprost 0.03% was found to be significantly more effective than timolol 0.5% (administered twice daily as an ophthalmic solution or once daily as a gel-forming solution) in randomised comparative trials in patients with ocular hypertension and glaucoma. Furthermore, after 1 to 6 months' treatment, the percentage of patients reaching a target IOP of < or =17mm Hg was significantly greater in the bimatoprost-treated groups than in those receiving timolol. Bimatoprost 0.03% ophthalmic solution was found to be at least as effective as topical latanoprost 0.005% administered once daily in two clinical trials. Reductions in IOP 16 and 20 hours postdose were greater in patients treated with bimatoprost, indicating superior control of IOP at timepoints throughout the dosage interval. In patients refractory to beta-blocker therapy, treatment with bimatoprost 0.03% produced greater reductions in diurnal IOP measurements than combination therapy with topical dorzolamide 2%/timolol 0.5%; approximately twice as many bimatoprost 0.03% recipients achieved an IOP of < or =16mm Hg. The most commonly reported adverse effect during clinical trials of once-daily bimatoprost 0.03% was conjunctival hyperaemia which occurred in 42 to 46% of patients treated. However, most cases were mild and only 1 to 4% of patients withdrew from treatment as a result. Overall withdrawal rates as a result of adverse events during clinical trials ranged from 2.6 to 7%. Bimatoprost has been reported to cause changes in the pigmentation of the periorbital skin, eyelashes and iris, and increase eyelash growth. The long-term consequences of these effects are unknown. Cardiopulmonary adverse effects, which have been associated with the use of beta-blockers such as timolol, were not reported in clinical trials of bimatoprost. Thus, in clinical trials of up to 1-year duration, bimatoprost 0.03% has been found to be effective in significantly lowering IOP and is generally well tolerated. It provides an alternative treatment option for patients in whom beta-blockers are contraindicated. Furthermore, bimatoprost provides an effective second-line treatment option in patients who do not achieve target IOP with other topical ocular hypotensive agents, or who experience unacceptable adverse effects. Wider clinical use of this drug will establish the place of bimatoprost in the treatment of open-angle glaucoma and ocular hypertension.     

Brinzolamide : a review of its use in the management of primary open-angle glaucoma and ocular hypertension

Brinzolamide is a highly specific carbonic anhydrase (CA) inhibitor which lowers intraocular pressure (IOP) by reducing the rate of aqueous humour formation. Formulated as a 1% ophthalmic suspension (Azopt) and administered twice or three times daily, brinzolamide is indicated for the topical management of primary open-angle glaucoma (POAG) and ocular hypertension (OH) as either monotherapy or adjunctive therapy with topical beta-blockers. As monotherapy in patients with POAG or OH, brinzolamide 1% demonstrated IOP-lowering efficacy that was significantly greater than placebo, equivalent to three-times-daily dorzolamide 2% but significantly lower than twice-daily timolol 0.5%. Brinzolamide 1% was equally effective in twice- and three-times-daily regimens producing diurnal mean IOP reductions from baseline in the range of 13.2-21.8%. When used adjunctively twice daily with timolol 0.5%, brinzolamide 1% was as effective as dorzolamide 2% and superior to placebo in lowering IOP in patients with POAG or OH. In clinical trials, brinzolamide 1% was well tolerated causing only nonserious adverse effects that were generally local, transient and mild to moderate in severity. The incidence of the most common adverse events associated with the use of brinzolamide 1% was either similar to (blurred vision and abnormal taste) or significantly lower than (ocular discomfort) with dorzolamide 2%. Topical brinzolamide 1% does not appear to produce the acid-base or electrolyte disturbances and severe systemic adverse effects characteristic of oral CA inhibitors. It can be used in patients unresponsive to beta-blockers or in whom beta-blockers are contraindicated. Brinzolamide 1% administered twice daily is among the least costly alternatives and adjuncts to beta-blocker therapy for glaucoma and is generally associated with less direct medical cost than dorzolamide. CONCLUSION: Brinzolamide 1% ophthalmic suspension administered twice or three times daily, as monotherapy or adjunctive therapy with topical beta-blockers, has good IOP-lowering efficacy in patients with POAG or OH that is equivalent to that of dorzolamide 2% (three times daily as monotherapy, twice daily as adjunctive therapy). Brinzolamide is generally well tolerated and does not produce the systemic adverse effects associated with oral CA inhibitors. It can be used in patients who are unresponsive to, intolerant of, or unable to receive, ophthalmic beta-blockers. Thus, brinzolamide, either as monotherapy or adjunctive therapy with topical beta-blockers, should be regarded as a good second-line option in the pharmacological management of POAG and OH, and may be preferred over dorzolamide because of significantly less ocular discomfort.     

Ocular carteolol: a review of its use in the management of glaucoma and ocular hypertension

Ocular carteolol (Mikelan), Teoptic, Ocupress) is a nonselective beta-adrenoceptor antagonist with intrinsic sympathomimetic activity (ISA). Ocular carteolol effectively reduces intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) or ocular hypertension (OH). Twice-daily administration of standard carteolol has generally similar IOP-lowering efficacy to other ocular beta-adrenoceptor antagonists such as timolol, betaxolol and metipranolol in patients with OAG or OH. In addition, long-term treatment with carteolol has similar efficacy to timolol and betaxolol in terms of reducing IOP and maintaining visual fields in patients with newly diagnosed primary OAG (POAG). The new long-acting formulation of once-daily carteolol has equivalent efficacy to the standard formulation of carteolol administered twice daily in patients with OAG or OH. Both the standard and long-acting formulations of ocular carteolol are generally well tolerated in terms of topical adverse effects involving the eyes or systemic adverse effects involving the cardiovascular system. Thus, twice-daily carteolol is a well established option in the treatment of glaucoma and OH, and the new once-daily formulation of long-acting carteolol offers similar efficacy and tolerability with a potential for improved patient adherence.     

Latanoprost : an update of its use in glaucoma and ocular hypertension

Latanoprost (Xalatan) is an ester analogue of prostaglandin F2alpha that reduces intraocular pressure (IOP) by increasing uveoscleral outflow. The IOP-lowering efficacy of latanoprost 0.005% lasts for up to 24 hours after a single topical dose, which allows for a once-daily dosage regimen. In patients with ocular hypertension or open-angle glaucoma, a single drop of latanoprost 0.005% solution (about 1.5 microg) administered topically once daily reduced diurnal IOP by 22 to 39% over 1 to 12 months' treatment in well-controlled trials; efficacy was maintained during treatment periods of up to 2 years. At this dosage, latanoprost was significantly more effective than timolol 0.5% twice daily in 3 of 4 large, double-blind, randomised studies, was generally as effective as bimatoprost or travoprost, and was significantly more effective than dorzolamide, brimonidine or unoprostone. Furthermore, in patients whose IOP was poorly controlled with timolol, switching to latanoprost monotherapy was at least as effective at lowering IOP as adding dorzolamide or pilocarpine to the regimen. Latanoprost has also shown significant additive effects when used in combination with one or more other glaucoma medications. The fixed combination of latanoprost plus timolol was significantly more effective than either of its individual components in two double-blind randomised studies and more effective than the fixed combination of dorzolamide and timolol in a 3-month, evaluator-masked study. Data in patients with angle-closure glaucoma are limited, but in patients with elevated IOP after undergoing iridotomy, latanoprost 0.005% once daily was significantly more effective than timolol 0.5% twice daily at reducing IOP over 12 weeks of treatment in a large double-blind, randomised study. Latanoprost is generally well tolerated and, unlike timolol, induces minimal systemic adverse events. In well-controlled, 6-month trials, the most commonly occurring drug-related ocular events in latanoprost recipients were mild to moderate conjunctival hyperaemia (3 to 15%) and iris colour change (2 to 9%); these seldom required patient withdrawal although the latter may be permanent. Latanoprost 0.005% as a single daily drop has shown good IOP-lowering efficacy in patients with open-angle glaucoma or ocular hypertension and does not produce the cardiopulmonary adverse effects associated with beta-blockers. Thus, latanoprost is a valuable addition to the first-line treatment options for patients with open-angle glaucoma or ocular hypertension. In addition, adjunctive treatment with latanoprost in patients who are refractory to beta-blocker therapy is a viable, second-line treatment option. Although preliminary findings are promising, wider clinical experience is required to define the place of latanoprost in the treatment of angle-closure glaucoma.     

Candesartan cilexetil: a pharmacoeconomic review of its use in chronic heart failure and hypertension

The addition of candesartan cilexetil (Atacand, Amias, Blopress, Kenzen, Ratacand) to standard therapy for chronic heart failure (CHF) provided important clinical benefits at little or no additional cost in France, Germany and the UK, according to a detailed economic analysis focusing on major cardiovascular events and prospectively collected resource-use data from the CHARM-Added and CHARM-Alternative trials in patients with CHF and left ventricular (LV) systolic dysfunction. Results of a corresponding cost-effectiveness analysis showed that candesartan cilexetil was either dominant over placebo or was associated with small incremental costs per life-year gained, depending on the country and whether individual trial or pooled data were used. Preliminary data from a US cost-effectiveness analysis based on CHARM data also showed favourable results for candesartan cilexetil. Two cost-effectiveness analyses of candesartan cilexetil in hypertension have been published, both conducted in Sweden. Data from the SCOPE trial in elderly patients with hypertension, which showed a significant reduction in nonfatal stroke with candesartan cilexetil-based therapy versus non-candesartan cilexetil-based treatment, were incorporated into a Markov model and an incremental cost-effectiveness ratio of euro12 824 per QALY gained was calculated (2001 value). Another modelled cost-effectiveness analysis of candesartan cilexetil was based on the ALPINE trial, in which the incidence of new-onset diabetes was significantly lower in patients with newly diagnosed hypertension who were randomised to candesartan cilexetil (with or without felodipine) than among those who received hydrochlorothiazide (with or without atenolol). Although candesartan cilexetil was dominant over hydrochlorothiazide, the ALPINE cost-effectiveness analysis relied on a small number of clinical events and did not evaluate the incremental cost of candesartan cilexetil per life-year or QALY gained. In conclusion, despite some inherent limitations, economic analyses incorporating CHARM data and conducted primarily in Europe have shown that candesartan cilexetil appears to be cost effective when added to standard CHF treatment in patients with CHF and compromised LV systolic function. The use of candesartan cilexetil as part of antihypertensive therapy in elderly patients with elevated blood pressure was also deemed to be cost effective in a Swedish analysis, primarily resulting from a reduced risk of nonfatal stroke (as shown in the SCOPE study); however, the generalisability of results to other contexts has not been established. Cost-effectiveness analyses comparing candesartan cilexetil with ACE inhibitors or other angiotensin receptor blockers in CHF or hypertension are lacking, and results reported for candesartan cilexetil in a Swedish economic analysis of ALPINE data focusing on outcomes for diabetes require confirmation and extension.     

An evaluation of the fixed-combination of latanoprost and timolol for use in open-angle glaucoma and ocular hypertension

Glaucoma is one of the leading causes of irreversible blindness worldwide. Although there is no cure for this chronic disease, medical treatment is aimed at reducing levels of intraocular pressure (IOP) using ocular hypotensive agents. Very often, patients require more than one IOP-reducing drug, resulting in complex medication regimens that may be difficult to maintain and that can lead to non-compliance. A fixed-combination (FC) ophthalmic solution consisting of the prostaglandin, latanoprost (0.005%), and the beta-blocker, timolol (0.5%), is now available. The primary mechanism of action of latanoprost is to increase uveoscleral outflow whereas timolol lowers IOP levels by decreasing the formation of aqueous humor in the ciliary epithelium. Due to the unique mechanism of action of latanoprost, once-daily dosing of one drop of FC latanoprost/timolol results in additional IOP reduction compared with either drug administered separately. FC latanoprost/timolol is well-tolerated and has a safety profile similar to that of its individual components. This combination drug provides a safe, effective and convenient alternative for the treatment of patients with elevated IOP levels uncontrolled with monotherapy.     

An evaluation of the fixed-combination of latanoprost and timolol for use in open-angle glaucoma and ocular hypertension

Glaucoma is one of the leading causes of irreversible blindness worldwide. Although there is no cure for this chronic disease, medical treatment is aimed at reducing levels of intraocular pressure (IOP) using ocular hypotensive agents. Very often, patients require more than one IOP-reducing drug, resulting in complex medication regimens that may be difficult to maintain and that can lead to non-compliance. A fixed-combination (FC) ophthalmic solution consisting of the prostaglandin, latanoprost (0.005%), and the β-blocker, timolol (0.5%), is now available. The primary mechanism of action of latanoprost is to increase uveoscleral outflow whereas timolol lowers IOP levels by decreasing the formation of aqueous humor in the ciliary epithelium. Due to the unique mechanism of action of latanoprost, once-daily dosing of one drop of FC latanoprost/timolol results in additional IOP reduction compared with either drug administered separately. FC latanoprost/timolol is well-tolerated and has a safety profile similar to that of its individual components. This combination drug provides a safe, effective and convenient alternative for the treatment of patients with elevated IOP levels uncontrolled with monotherapy.     

Escitalopram: a pharmacoeconomic review of its use in depression

Escitalopram (Cipralex), a new highly selective serotonin reuptake inhibitor (SSRI), is the active S-enantiomer of RS-citalopram. It is effective in the treatment of patients with major depressive disorder (MDD) and may have a faster onset of therapeutic effect than citalopram. It has also been shown to lead to improvements in measures of QOL. Escitalopram is generally well tolerated, with nausea being the most common adverse event associated with its use. Modelled pharmacoeconomic analyses found escitalopram to have a cost-effectiveness and cost-utility advantage over other SSRIs, including generic citalopram and fluoxetine and branded sertraline, and also over the serotonin-noradrenaline reuptake inhibitor (SNRI) venlafaxine extended-release (XR). These studies used a decision-analytic approach with a 6-month time horizon and were performed in Western Europe (year of costing 2000 or 2001). Cost-effectiveness ratios for escitalopram, in terms of cost per successfully treated patient over 6 months, ranged from Euro 871 to Euro 2598 in different countries, based on direct costs and remission rates, and were consistently lower (i.e. more favourable) than the ratios for comparators (Euro 970 to Euro 3472). Outcomes similarly favoured escitalopram when indirect costs (represented by those associated with sick leave and loss of productivity) were included. The results of comparisons with citalopram, fluoxetine and sertraline were not markedly affected by changes to assumptions in sensitivity analyses, although comparisons with venlafaxine XR were sensitive to changes in the remission rate. The mean number of QALYs gained during the 6-month period was similar for all drugs evaluated, but direct costs were lower with escitalopram, leading to lower cost-utility ratios than for comparators. Incremental analyses performed in two of the studies confirmed the cost-effectiveness and cost-utility advantage of escitalopram. A prospective, 8-week comparative pharmacoeconomic analysis found that escitalopram achieved similar efficacy to venlafaxine XR, but was associated with 40% lower direct costs (Euro 85 vs Euro 142 per patient over 8 weeks; 2001 costs), although this difference did not reach statistical significance. In both the modelled and prospective analyses, the differences in overall direct costs were mainly due to lower secondary care costs (in particular those related to hospitalisation) with escitalopram. In the prospective analysis, escitalopram had lower estimated drug acquisition costs than venlafaxine XR. CONCLUSION: Escitalopram, the S-enantiomer of RS-citalopram and a highly selective SSRI, is an effective antidepressant in patients with MDD, has a favourable tolerability profile, and, on the basis of available data, appears to have a rapid onset of therapeutic effect. Modelled pharmacoeconomic analyses from Western Europe suggest that it may be a cost-effective alternative to generic citalopram, generic fluoxetine and sertraline. Although the available data are less conclusive in comparison with venlafaxine XR, escitalopram is at least as cost effective as the SNRI based on a prospective study, and potentially more cost effective based on modelled analyses. Overall, clinical and pharmacoeconomic data support the use of escitalopram as first-line therapy in patients with MDD.     

Brinzolamide/timolol fixed combination: a new ocular suspension for the treatment of open-angle glaucoma and ocular hypertension

For the treatment of open-angle glaucoma, the most frequent cause of irreversible visual loss, fixed combinations of different topical intraocular pressure (IOP) lowering molecules have gained an important role in recent years. The use of fixed combinations reduces the number of daily instillations, which promotes adherence to the prescribed medication and diminishes the exposition of the ocular surface to preservatives. The fixed combination of brinzolamide and timolol was recently approved by the European Medicines Agency (EMEA) and is now available in several countries in Europe. It contains two molecules widely used to treat glaucoma: timolol 0.5% (5 mg/ml) and brinzolamide 1% (10 mg/ml) in ophthalmic suspension formulation. This fixed combination is approved for twice-daily instillation to reduce elevated IOP in open-angle glaucoma and ocular hypertension. The brinzolamide/timolol fixed combination provides an approximately 30 – 33% IOP reduction from the untreated baseline IOP of 25 – 27 mmHg; thus, it is more potent than either of its ingredients alone. It is similarly effective but better tolerated than the dorzolamide/timolol fixed combination, which consists of molecules from the same pharmacological classes. The brinzolamide/timolol fixed combination can be used by itself as a separate therapy, but owing to the additivity of its ingredients to IOP-lowering drugs belonging to other classes, it may also be administered adjunctive to other IOP-reducing molecules, most importantly topical prostaglandin analogues. The ocular and systemic tolerance of the brinzolamide/ timolol fixed combination was reported favorable in Phase III studies, but no long-term clinical experience with this preparation is available at present.     

Infliximab: a pharmacoeconomic review of its use in rheumatoid arthritis

Infliximab (Remicade), a biological disease-modifying antirheumatic drug (DMARD), binds to and inhibits the activity of tumour necrosis factor-alpha, which is thought to play an important role in the pathophysiology of rheumatoid arthritis. Intravenous infliximab plus methotrexate is recommended in patients with rheumatoid arthritis who have not achieved satisfactory disease control with adequate courses of other DMARDs. Pharmacoeconomic analyses have been based on efficacy data from the pivotal placebo-controlled Anti-Tumour Necrosis Factor Trial in Rheumatoid Arthritis with Concomitant Therapy (ATTRACT) trial in patients with active, refractory rheumatoid arthritis. Infliximab every 8 weeks plus methotrexate demonstrated rapid and sustainable improvements in clinical response, delayed radiographic progression, and/or improved functional status and health-related QOL compared with placebo plus methotrexate at weeks 30, 54 and 102. In cost-utility analyses of infliximab plus methotrexate conducted from a healthcare payer and/or societal perspective in the US, Europe, Portugal, Sweden and the UK, infliximab 3 mg/kg every 8 weeks plus methotrexate was associated with acceptable (<$US50,000 per discounted QALY gained) cost-utility ratios relative to methotrexate alone in patients with active, refractory rheumatoid arthritis. When only direct costs were considered, the lifetime incremental cost per discounted QALY gained with infliximab plus methotrexate relative to methotrexate alone was $US30,500-38,700 (year of costing 1998 or not reported; treatment duration 54 or 102 weeks or lifelong) in the US and Europe analyses, and euro39 500 (year of costing not reported; lifelong treatment) in the Portuguese analysis. The cost-utility ratios were more favourable when lost productivity costs or the additional benefit of infliximab on radiographic stabilisation were considered. In the Swedish and UK analyses with a 10-year time horizon, infliximab plus methotrexate for 1 or 2 years was associated with cost-utility ratios of euro28 600-56 100 (year of costing not reported) when direct costs were considered, and euro3440-48 200 when direct costs plus loss-of-productivity costs were considered. In conclusion, cost-utility analyses, which were based on modelling of data from the pivotal clinical trial of infliximab plus methotrexate, indicate that infliximab plus methotrexate is associated with acceptable cost-effectiveness ratios (<$US50,000 per discounted QALY gained) relative to methotrexate monotherapy in patients with active rheumatoid arthritis who have not responded to previous methotrexate or other DMARD therapy. The cost effectiveness of infliximab versus other DMARDs is at present unclear, but will be clarified when appropriate data from directly comparative clinical and/or pharmacoeconomic studies become available. In patients in whom adequate courses of other DMARDs have failed to achieve satisfactory disease control, infliximab plus methotrexate may prevent or delay disability, which may produce reductions in nondrug costs that can help offset its acquisition cost.     

他氟前列素治疗开角型青光眼和高眼压症的有效性及安全性评价

目的:综述他氟前列素滴眼液降低开角型青光眼和高眼压症患者眼内压的有效性及安全性评价。方法:使用"他氟前列素"、"开角型青光眼"、"高眼压症"、"有效性"、"安全性"作为检索词在PubMed数据库和中文数据库维普全文、电子期刊等对已发表的文献进行检索,检索2004年至2015年英文文献共52篇及中文文献多篇,包括多中心临床研究及药品信息资料,并对检索结果进行归纳性分析。结果:现有的研究已显示,他氟前列素是一种有效降低眼内压的药物。循证医学也发现他氟前列素安全有效,患者依从性良好。不含防腐剂他氟前列素的降眼压效果与含防腐剂的相同。结论:研究提示,他氟前列素每日1次滴眼可安全有效地降低开角型青光眼及高眼压症患者的眼内压。     

Quetiapine: a pharmacoeconomic review of its use in bipolar disorder

This article briefly summarizes the burden of bipolar disorder and the clinical profile of quetiapine (Seroquel?) in the management of bipolar disorder, followed by a detailed review of pharmacoeconomic analyses. Quetiapine is an atypical antipsychotic that is available in numerous countries as immediate-release and extended-release tablets for the treatment of major psychiatric disorders, including bipolar disorder. Randomized, double-blind, placebo-controlled trials with quetiapine have demonstrated its efficacy in bipolar I and II disorders, and the drug has been generally well tolerated in clinical trials. Three cost-effectiveness analyses of maintenance therapy in bipolar I disorder, which used similar Markov models and incorporated data from key clinical trials and a number of other sources, showed that quetiapine, as adjunctive therapy with mood stabilizers (lithium or divalproex), was a cost-effective treatment option from the healthcare payer perspective in the UK and the US. Quetiapine either dominated comparators (typically mood stabilizers alone) or was associated with incremental cost-effectiveness ratios that were usually well below widely accepted thresholds of cost effectiveness. One of the studies evaluated extended-release quetiapine, although clinical efficacy data used in the Markov model were for the immediate-release formulation. In another analysis, which used a discrete-event simulation model and was conducted from the perspective of the UK healthcare payer, quetiapine monotherapy was cost effective compared with olanzapine monotherapy as maintenance treatment for all phases of bipolar I or II disorder. In this model, favourable results were also shown for quetiapine (with or without mood stabilizers) compared with a wide range of maintenance therapy regimens. Another modelled analysis conducted from the UK healthcare payer perspective showed that quetiapine was dominated by haloperidol in the short-term treatment of a manic episode in patients with bipolar I disorder. Both favourable and unfavourable results have been reported in cost analyses of quetiapine in bipolar disorder (type I or type not specified). Possible explanations for some of the variability in results of the pharmacoeconomic analyses include heterogeneity among the models in terms of input parameters or assumptions in the base-case analyses, country- or region-specific differences in estimates of healthcare resource use and associated costs, variability in treatment alternatives, and differences in the year of costing and discounting used in the analyses. In addition, some of the studies had short time horizons and focused on acute manic episodes only, whereas others were longer-term analyses that considered the full spectrum of health states in patients with bipolar disorder. Various limitations of the studies have been recognized, and results from one country may not be applicable to other countries. In conclusion, results of available pharmacoeconomic analyses provide evidence of the cost effectiveness of quetiapine as an adjunct to mood stabilizers for maintenance therapy in (primarily type I) bipolar disorder from a healthcare payer perspective in the UK and the US. Some evidence is available to support the cost effectiveness of quetiapine monotherapy or the use of extended-release quetiapine as adjunctive therapy with mood stabilizers in this setting, although further analyses appear to be warranted. Whether these findings apply to other geographical regions requires further study. Evidence for the long-term (>2-year) cost effectiveness of quetiapine in bipolar disorder is currently limited and further studies are also needed to address the cost effectiveness of quetiapine from a societal perspective and in bipolar II disorder.     

Galantamine: a pharmacoeconomic review of its use in Alzheimer's disease

Galantamine is one of several orally administered cholinesterase inhibitors that improve cognition in patients with mild to moderate Alzheimer's disease. Compared with placebo, galantamine 16 or 24 mg/day improved cognition and activities of daily living, delayed emergence of behavioural symptoms and reduced caregiver burden in three pivotal randomised studies of 5 or 6 months' duration. Galantamine may reduce the considerable economic burden of Alzheimer's disease by delaying the need for full-time care (FTC) in patients with mild to moderate Alzheimer's disease. In pharmacoeconomic analyses with a time horizon of 10 years conducted in Canada, Sweden, The Netherlands and the US, data from the pivotal trials were incorporated into a model to examine economic implications associated with galantamine treatment. FTC was defined in the model as the consistent requirement for caregiving and supervision for the greater part of each day regardless of the location of care and the identity of caregiver. When the effect of galantamine 16 or 24 mg/day was analysed from the perspective of a comprehensive healthcare payer, treatment was associated with cost savings (inclusive of drug costs) relative to no treatment, regardless of country for which the model was customised. Cost savings resulted from the delay in the time until FTC was required in patients with mild to moderate disease. In sensitivity analyses, cost savings were most sensitive to the cost of institutional care. In the analyses that considered the effect of galantamine 24 mg/day solely on cognition, galantamine was predicted to reduce the time FTC was required by approximately 10% in patients with mild to moderate Alzheimer's disease compared with no pharmacological treatment. Greater reductions in the time that FTC was required were predicted when the effects of galantamine 16 or 24 mg/day on behavioural symptoms in addition to cognition were considered in the US analysis or in sensitivity analyses in studies in other countries. In conclusion, pharmacoeconomic analyses, which were based on modelling of data from pivotal clinical trials with galantamine and included drug costs, indicate that galantamine treatment may result in cost savings from a healthcare payer perspective. The effects of galantamine on cognition and behavioural symptoms in patients with mild to moderate Alzheimer's disease are predicted to delay the need for FTC, which may result in cost savings. From a societal perspective, the caregiver burden of caring for a patient with Alzheimer's disease in the community may be decreased and the time that patients have without severe disease may be prolonged.     

Etanercept: a pharmacoeconomic review of its use in rheumatoid arthritis

Etanercept (Enbrel), which inhibits the activity of tumour necrosis factor-alpha, is indicated in the treatment of patients with active rheumatoid arthritis (RA). A lifetime cost-utility analysis in patients with severe disease-modifying antirheumatic drug (DMARD)-resistant RA in the UK suggested that etanercept is associated with acceptable cost-utility ratios relative to traditional nonbiological DMARDs. In a 12-month cost-utility study in Spain, etanercept was predicted to be dominant over infliximab plus methotrexate in patients with active, refractory RA with regards to the cost per QALY gained and cost per American College of Rheumatology (ACR) 20 response achieved. In short-term cost-effectiveness analyses conducted in the US, the cost effectiveness of etanercept relative to other treatments in patients with methotrexate-naive or -resistant RA depends on whether predicted incremental cost-effectiveness ratios of at least USD 41,900 per ACR 20 response or USD 34,800 per ACR 70 weighted response over a 6-month period are considered acceptable (1999 values). The relative efficacy and cost effectiveness of etanercept and other biological DMARDs will be clarified when appropriate data from directly comparative clinical and/or long-term pharmacoeconomic studies become available. Etanercept may prevent or delay disability, which may produce reductions in nondrug costs that could help offset its acquisition cost.     

Memantine: a pharmacoeconomic review of its use in moderate-to-severe Alzheimer's disease

Memantine (Ebixa, Namenda, Axura) is an uncompetitive NMDA receptor antagonist used in the management of patients with moderate-to-severe Alzheimer's disease. It is currently the only drug approved for use in these more advanced stages of the disease. Significant reductions in functional and cognitive decline have been demonstrated with memantine relative to placebo in randomised, double-blind trials in this patient population. Clinical trial and postmarketing surveillance data indicate that the drug is generally well tolerated.Two fully published modelled cost-effectiveness analyses of memantine in moderate-to-severe Alzheimer's disease have been conducted in the UK and Finland, in which patient progression was simulated through health states related to dependency, residential setting and cognitive function. Although the specific costs included in the analyses varied, as did the study perspective and geographical location, results of the base-case analyses consistently showed that memantine was dominant over no pharmacological treatment. In the UK and Finnish analyses, memantine increased the duration of independence by 1.3 and 4.1 months, respectively, and the time to institutionalisation by 0.8 and 1 month. Mean total per-patient costs were reduced by 1963 pounds over 2 years (2003 costs) in the UK analysis and by 1687 eurossover 5 years (2001 costs) in the Finnish analysis. Memantine was also associated with a small gain in quality-adjusted life expectancy in the UK model. In sensitivity analyses, memantine remained dominant for almost all plausible changes to key variables.Memantine reduced total societal costs by $1090 per patient per month (1999 costs) compared with no pharmacological treatment over 28 weeks in a resource utilisation and cost analysis conducted alongside a pivotal US trial in patients with moderate-to-severe Alzheimer's disease. Results were primarily driven by reductions in total caregiver costs, which included the opportunity cost of time spent in caregiving tasks, and in direct nonmedical costs, which included the cost of care in a nursing home or similar institution.In conclusion, in patients with moderate-to-severe Alzheimer's disease, memantine is associated with significant reductions in functional and cognitive decline compared with no pharmacological treatment. Available pharmacoeconomic data from Europe and the US, despite some inherent limitations, support the use of memantine as a cost-effective treatment in this patient population, although definitive conclusions are not feasible because of limited data.     

Linezolid: a pharmacoeconomic review of its use in serious Gram-positive infections

Linezolid (Zyvox), the first available oxazolidinone antibacterial agent, has good activity against Gram-positive pathogens, including multidrug-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Randomised multicentre trials in patients with various types of serious Gram-positive infections showed that clinical cure rates with linezolid were similar to those with vancomycin or teicoplanin. In some subgroup analyses, which must be interpreted with a degree of caution, clinical advantages were noted for linezolid (e.g. versus vancomycin in confirmed MRSA nosocomial pneumonia and MRSA-complicated skin and soft tissue infections). Although generally well tolerated, gastrointestinal adverse effects are relatively common with linezolid and it has been associated with thrombocytopenia and myelosuppression. The oral bioavailability of linezolid is approximately 100%, thus allowing sequential intravenous-to-oral administration without changing the drug or dosage regimen. Healthcare resource use data from various countries indicate that this practical advantage translates into at least a trend towards reduced length of hospital stay compared with vancomycin, which may offset its several-fold higher acquisition cost. Modelled analyses from the US, despite some limitations, indicate that, compared with vancomycin, linezolid is associated with lower total hospitalisation costs for the treatment of patients with cellulitis and has a favourable incremental cost-effectiveness ratio of approximately US30,000 dollars per QALY gained (2001 value) for patients with ventilator-associated pneumonia. Broadly similar results have also been reported in modelled analyses from other countries. In conclusion, for patients with serious Gram-positive infections, including those caused by suspected or proven multidrug-resistant pathogens such as MRSA, linezolid is an effective and generally well tolerated therapeutic option. Linezolid is currently the only antibacterial agent with good activity against MRSA that can be administered orally (as well as intravenously). It may be particularly useful as an alternative to vancomycin in patients who have impaired renal function, poor or no intravenous access, require outpatient therapy, or who have been unable to tolerate glycopeptides. Healthcare resource use studies and pharmacoeconomic analyses generally support the use of linezolid in some subgroups of patients, although results should be interpreted with due consideration of the study limitations.     

Trastuzumab: a pharmacoeconomic review of its use in early breast cancer

Trastuzumab (Herceptin) is a monoclonal antibody approved for the treatment of breast cancer that overexpresses human epidermal growth factor receptor 2 (HER2). Well designed clinical trials in women with early breast cancer have demonstrated that 1 years' therapy with adjuvant intravenous trastuzumab (a loading dose followed by 6 mg/kg every 3 weeks or 2 mg/kg weekly) significantly improves disease-free survival and overall survival compared with observation (subsequent to chemotherapy) or chemotherapy alone in women with HER2-positive disease. In the HERA trial, disease-free survival was estimated to improve by 6.3% at 3 years in the trastuzumab group compared with the observation group. Trastuzumab is generally well tolerated. The most common adverse events are infusion-related symptoms, such as fever and chills, which usually occur with administration of the first dose. Cardiotoxicity occurs in a small proportion of patients receiving trastuzumab, particularly when coadministered with anthracyclines, and cardiac assessment is recommended for all patients at baseline and at 3-monthly intervals. In modelled cost-effectiveness analyses based on data from clinical trials in patients with HER2-positive early breast cancer, adjuvant trastuzumab was predicted to be cost effective from a healthcare payer or societal perspective in several countries. Incremental costs per QALY or life-year gained with trastuzumab administered subsequent to or concurrent with chemotherapy compared with chemotherapy alone were consistently within accepted local thresholds for cost effectiveness. Sensitivity analyses demonstrated that these results remained generally robust to plausible changes in key model assumptions. In conclusion, in patients with HER2-positive early breast cancer, the addition of adjuvant trastuzumab is clinically effective in improving disease-free survival. Available pharmacoeconomic data from several countries, despite some inherent limitations, support the use of adjuvant trastuzumab for 1 year as a cost-effective treatment relative to chemotherapy alone in this patient population.     

Ocular carteolol. A review of its pharmacological properties, and therapeutic use in glaucoma and ocular hypertension.

Carteolol is a relatively potent nonselective beta-adrenoceptor antagonist with partial agonist activity. It is used topically to reduce elevated intraocular pressure (IOP) in patients with glaucoma or ocular hypertension. Twice-daily ocular administration of carteolol 1 or 2% lowers IOP by approximately 32% on average in patients with these conditions, an efficacy equivalent to that of timolol 0.25 or 0.5%. Carteolol eyedrops lack local anaesthetic activity, appear to cause less local irritation than timolol, and produce less pronounced decreases in heart rate or dyspnoea, possibly due to partial agonist activity. The latter activity may also improve retinal perfusion. Thus, although additional comparative trials are needed to accurately assess the precise place of carteolol in therapy, this drug offers a useful alternative to timolol in the management of conditions associated with a raised IOP, and may have advantages in older patients with regard to its tolerability profile, although careful monitoring is still wise.     

Insulin lispro: a pharmacoeconomic review of its use in diabetes mellitus

Insulin lispro is a recombinant insulin analogue with transposed amino acids (proline and lysine) at positions 28 and 29 near the C-terminus of the B-chain. The most prominent practical advantage of insulin lispro over human soluble insulin lies in its very rapid onset of action. This property allows it to be injected immediately before meals and minimises the demands made on patients with type 1 diabetes mellitus, and those with type 2 disease who require insulin, by the ongoing need for careful meal planning and timing. Numerous clinical studies have shown significant improvements in postprandial glycaemic control, with some evidence of reduced rates of severe or nocturnal hypoglycaemia, relative to conventional human insulin in patients receiving lispro-based insulins. Quality-of-life studies show consistent preferences by patients for and increased treatment satisfaction with insulin lispro over human soluble insulin, particularly with variations of the Diabetes Treatment Satisfaction Questionnaire. Willingness of patients and taxpayers to pay additional costs for insulin lispro or a premixed lispro-based formulation over conventional human insulins, and cost benefits favouring formulary inclusion, have been shown in well designed studies carried out in Australia and Canada. Spanish data suggest cost effectiveness in terms of episodes of severe hypoglycaemia avoided, and preliminary German resource utilisation data indicate cost savings related to reduced hospitalisation and general practice costs, with insulin lispro relative to human soluble insulin. CONCLUSIONS: Insulin lispro and premixed formulations of lispro-based insulins offer quality-of-life improvements relative to conventional human insulins in patients with diabetes mellitus. Participants in well designed studies have expressed a preference for lispro-based insulins and have been shown to be willing to pay for the advantages they offer, and current cost-benefit data favour the inclusion of these insulins in formularies and their reimbursement by third party payers. Further research into the pharmacoeconomic implications of insulin lispro use in the long term is needed, particularly with respect to effects on indirect costs and those associated with complications of diabetes mellitus.