Clinical spectrum of the osmotic-controlled release oral delivery system (OROS), an advanced oral delivery form

Composite nanoparticles take aim at cancer

Nanoparticles have properties that are useful for the diagnosis and treatment of cancer, including their size-dependent properties, stability in solvent, ideal size for delivery within the body, and tunable surface chemistry for targeted delivery. Several different nanoparticle building blocks possessing varied functionality can be assembled into one multifunctional composite nanoparticle, further expanding their potential use in cancer diagnostics and therapeutics. Here, we present several examples of the types of functional composite nanoparticles that have been studied, in addition to highlighted applications of their uses.

Costs and effects of paliperidone extended release compared with alternative oral antipsychotic agents in patients with schizophrenia in Greece: a cost effectiveness study

BACKGROUND

To compare the costs and effects of paliperidone extended release (ER), a new pharmaceutical treatment for the management of schizophrenia, with the most frequently prescribed oral treatments in Greece (namely risperidone, olanzapine, quetiapine, aripiprazole and ziprasidone) over a 1-year time period.

METHODS

A decision tree was developed and tailored to the specific circumstances of the Greek healthcare system. Therapeutic effectiveness was defined as the annual number of stable days and the clinical data was collected from international clinical trials and published sources. The study population was patients who suffer from schizophrenia with acute exacerbation. During a consensus panel of 10 psychiatrists and 6 health economists, data were collected on the clinical practice and medical resource utilisation. Unit costs were derived from public sources and official reimbursement tariffs. For the comparators official retail prices were used. Since a price had not yet been granted for paliperidone ER at the time of the study, the conservative assumption of including the average of the highest targeted European prices was used, overestimating the price of paliperidone ER in Greece. The study was conducted from the perspective of the National Healthcare System.

RESULTS

The data indicate that paliperidone ER might offer an increased number of stable days (272.5 compared to 272.2 for olanzapine, 265.5 f risperidone, 260.7 for quetiapine, 260.5 for ziprasidone and 258.6 for aripiprazole) with a lower cost compared to the other therapies examined (euro 7,030 compared to euro 7,034 for olanzapine, euro 7,082 for risperidone, euro 8,321 for quetiapine, euro 7,713 for ziprasidone and euro 7,807 for aripiprazole). During the sensitivity analysis, a +/- 10% change in the duration and frequency of relapses and the economic parameters did not lead to significant changes in the results.

CONCLUSION

Treatment with paliperidone ER can lead to lower total cost and higher number of stable days in most of the cases examined.

Diagnostic and treatment challenges of chronic fatigue syndrome: role of immediate-release methylphenidate

Chronic fatigue syndrome (CFS) is a distinct entity belonging to the group of persistent fatigue that can be challenging to diagnose and to treat. It is characterized by a combination of prolonged fatigue, other nonspecific somatic manifestations and neuropsychological symptoms, including difficulties with concentration, short-term memory and thinking, as well as impaired attention and slowed processing speed. Neurostimulants increasing dopamine and norepinephrine activity, such as bupropion, dextroamphetamine and recently immediate-release methylphenidate have been advocated to improve neurocognitive deficits. The use of immediate-release methylphenidate in CFS has been shown in one small study. Using the positive results of this study and the well-known beneficial effects of the drug on a range of similar cognitive symptoms in attention-deficit/hyperactivity disorder, this perspective addresses CFS and other related disorders and provides a discussion on the potential promising role of methylphenidate in the therapeutic armamentarium of CFS.

Paliperidone extended-release tablets in schizophrenia patients previously treated with risperidone

To assess the effect of paliperidone extended-release (ER) tablets in patients with acute symptoms who had previously received risperidone. Data for this post-hoc analysis were pooled from three 6-week, double-blind, placebo-controlled trials in patients treated with paliperidone ER 3-12 mg/day or placebo. Patients had to have received risperidone for > or =4 weeks within 2 weeks of study entry. Assessments were done using the Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity scale, Personal and Social Performance scale, the Simpson-Angus Scale , and adverse event (AE) reports. Altogether, 198 patients (paliperidone ER, n=142; placebo, n=56) met the established criteria. Mean (SD) duration of prior risperidone treatment and dose were 418.8 (572.8) days and 4.4 (2.5) mg/day for paliperidone ER and 527.0 (805.3) days and 4.1 (2.5) mg/day for placebo. Study completion rates were 61.3% for paliperidone ER versus 42.9% for placebo. At endpoint, paliperidone ER showed significant improvement versus placebo (P<0.05) in Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity, and Personal and Social Performance scores. Mean baseline Simpson-Angus Scale scores were low, with no significant changes at endpoint in either group. AEs > or =10% with paliperidone ER versus placebo were headache (16.2 vs. 16.1%), insomnia (14.1 vs. 16.1%), and agitation (8.5 vs. 10.7%). AE-related discontinuations were 2.1% with paliperidone ER and 5.4% with placebo. In patients who had received risperidone previously but remained sufficiently symptomatic for enrollment, paliperidone ER was significantly more effective than placebo in reducing symptoms and producing functional gains.

Efficacy and safety of paliperidone extended-release tablets: results of a 6-week, randomized, placebo-controlled study

BACKGROUND

Paliperidone extended-release tablet (paliperidone ER; Invega, Janssen L.P., Titusville, New Jersey) is an oral psychotropic for schizophrenia treatment.

METHODS

Efficacy and safety of once-daily paliperidone ER (6 and 12 mg) were assessed versus placebo in 444 patients with acute schizophrenia in a 6-week, multicenter, double-blind, randomized, parallel-group study. An olanzapine (10 mg) treatment arm was included to confirm trial validity.

RESULTS

Both doses of paliperidone ER demonstrated significant improvement in Positive and Negative Syndrome Scale (PANSS) total score (p < or = .006) and certain PANSS Marder factor scores compared with placebo (p < or = .025); PANSS total score also improved in the olanzapine treatment arm. Paliperidone ER 6 mg (p < or = .008), but not 12 mg, was associated with significant improvements in personal and social performance. The incidence of treatment-emergent adverse events (AEs) for paliperidone ER 6 mg was comparable with placebo and slightly greater with paliperidone ER 12 mg. Changes in blood glucose and lipid levels with paliperidone ER were comparable with placebo. Two patients treated with paliperidone ER experienced glucose-related AEs. Body-weight increases of 1-2 kg were observed with paliperidone ER. Although there were increases in plasma prolactin levels with paliperidone ER treatment, the incidence of prolactin-related AEs was < or =1%.

CONCLUSIONS

In this study, paliperidone ER, particularly the 6-mg dose, was effective and well tolerated, and provides a valuable new treatment option for schizophrenia.

Paliperidone ER: a review of the clinical trial data

Paliperidone extended-release tablet (paliperidone ER; INVEGA()) is an oral antipsychotic for the treatment of schizophrenia. The recommended dose range is 3-12 mg per day. Paliperidone ER utilizes the OROS((R)) delivery system, which allows for once-daily dosing. Its pharmacokinetic profile results in a more stable serum concentration. Paliperidone is 9-hydroxyrisperidone, the chief active metabolite of risperidone. It undergoes limited hepatic metabolism, thereby minimizing the risks of hepatic drug-drug and drug-disease interactions. Three 6-week trials in patients with acute schizophrenia reported that paliperidone ER was effective, well tolerated, and produced clinically meaningful improvements in personal and social functioning compared with placebo. Post-hoc analysis of these trials in various populations, including recently diagnosed, elderly and more severely ill patients, those with sleep disturbances and those with predominant negative symptoms demonstrated improvement as well. Paliperidone ER was also significantly better than placebo in the prevention of symptom recurrence in a 6-month maintenance study. The most common clinically relevant adverse events associated with paliperidone ER were extrapyramidal symptoms, tachycardia and somnolence. The incidence of Parkinsonism, akathisia and use of anticholinergic medications increased in a dose-related manner. Further, modest QTc interval prolongation was observed but did not produce clinical symptoms. Similar to risperidone, paliperidone ER is associated with increases in serum prolactin levels. Overall, paliperidone ER was effective, well tolerated and provides a new treatment option for patients with schizophrenia.

Paliperidone Extended-Release Tablets: A New Atypical Antipsychotic

This article reviews the use of the new atypical antipsychotic drug paliperidone extended-release (Pal-ER). Pal-ER is a delayed-release formulation that provides continual drug delivery over 24 hours and reduces fluctuations in serum drug concentrations. This delayed release minimizes side effects related to high serum levels that occur with immediate-release formulations. Pal-ER is effective, safe, and relatively well tolerated. Although Pal-ER does not have any major advantages or disadvantages compared with other antipsychotic drugs, it has unique pharmacological properties and may be a beneficial alternative medication for some patients.

Antipsychotic efficacy: relationship to optimal D2-receptor occupancy

Clinically important differences exist between antipsychotic agents and formulations in terms of safety and tolerability. Features of the biochemical interaction between the antipsychotic and the D2-receptor may underlie these differences. This article reviews current information on the relationship between antipsychotic receptor occupancy and clinical response. A literature search was performed using the keywords 'antipsychotic or neuroleptic', 'receptor' and 'occupancy' and 'dopamine' and 'D2' supplemented by the authors' knowledge of the literature. Imaging and clinical data have generally supported the hypotheses that optimal D2-receptor occupancy in the striatum lies in a 'therapeutic window' between approximately 65 and approximately 80%, however, pharmacokinetic and pharmacodynamic properties of a drug should also be taken into account to fully evaluate its therapeutic effects. Additional research, perhaps in preclinical models, is needed to establish D2-receptor occupancy in various regions of the brain and the optimal duration of D2-receptor blockade in order to maximise efficacy and tolerability profiles of atypical antipsychotics and thereby improve treatment outcomes for patients with schizophrenia.

Paliperidone: quo vadis?

Paliperidone, the 9-hydroxy metabolite of risperidone, was approved on 20 December, 2006 by the US Food and Drug Administration for the treatment of schizophrenia. It is also being tested for the treatment of bipolar mania. An on-line query of http://www.pubmed.gov and http://www.clinicaltrials.gov for 'paliperidone' and '9-hydroxy-risperidone' was done, along with an examination of poster presentations at scientific meetings held in 2006. Three 6-week pivotal clinical trials of paliperidone extended-release at fixed doses ranging from 3 to 15 mg administered orally once daily in the treatment of acute schizophrenia demonstrated superior efficacy to placebo. A favourable tolerability profile was also evidenced, except for prolactin elevation and dose-related extra-pyramidal effects. A relapse prevention study provides evidence of superiority of paliperidone over placebo in the maintenance of response. Safety has also been assessed in patients with schizophrenia who are 65 years or older. At present there are no studies available that are powered to directly compare paliperidone to other second-generation antipsychotics, including risperidone. With the impending availability of oral risperidone as a generic medication, cost of oral paliperidone will likely become a significant obstacle to its use.