The threshold rate of oral atypical anti-psychotic adherence at which paliperidone palmitate is cost saving.

OBJECTIVE: To identify, estimate, and compare 'real world' costs and outcomes associated with paliperidone palmitate compared with branded oral atypical anti-psychotics, and to estimate the threshold rate of oral atypical adherence at which paliperidone palmitate is cost saving. METHODS: Decision analytic modeling techniques developed by Glazer and Ereshefsky have previously been used to estimate the cost-effectiveness of depot haloperidol, LAI risperidone, and, more recently, LAI olanzapine. This study used those same techniques, along with updated comparative published clinical data, to evaluate paliperidone palmitate. Adherence rates were based on strict Medication Event Monitoring System (MEMS) criteria. The evaluation was conducted from the perspective of US healthcare payers. RESULTS: Paliperidone palmitate patients had fewer mean annual days of relapse (8.7 days; 6.0 requiring hospitalization, 2.7 not requiring hospitalization vs 17.8 days; 12.4 requiring hospitalization, 5.4 not requiring hospitalization), and lower annual total cost ($20,995) compared to oral atypicals (mean $22,481). Because paliperidone palmitate was both more effective and less costly, it is considered economically dominant. Paliperidone palmitate saved costs when the rate of adherence of oral atypical anti-psychotics was below 44.9% using strict MEMS criteria. Sensitivity analyses showed results were robust to changes in parameter values. For patients receiving 156 mg paliperidone palmitate, the annual incremental cost was $1216 per patient (ICER = $191 per day of relapse averted). Inclusion of generic risperidone (market share 18.6%) also resulted in net incremental cost for paliperidone palmitate ($120; ICER = $13). Limitations of this evaluation include use of simplifying assumptions, data from multiple sources, and generalizability of results. CONCLUSIONS: Although uptake of LAIs in the US has not been as rapid as elsewhere, many thought leaders emphasize their importance in optimizing outcomes in patients with adherence problems. The findings of this analysis support the cost-effectiveness of paliperidone palmitate in these patients.

Are the long-acting intramuscular formulations of risperidone or paliperidone palmitate associated with post-injection delirium/sedation syndrome? An assessment of safety databases.

Long-acting injectable (LAI) formulations of antipsychotics are valuable treatment alternatives for patients with psychotic disorders, and understanding their safe use is critical. Post-injection delirium/sedation syndrome (PDSS) has been reported following treatment with one atypical antipsychotic LAI. Clinical databases of risperidone LAI and paliperidone palmitate were explored to identify if cases of PDSS had been observed. No cases of PDSS were identified in 15 completed trials of 3,164 subjects (approximately 115,000 injections) or the postmarketing safety database of risperidone LAI. Only one case of PDSS was identified among 10 completed trials (3,817 subjects, 33,906 injections) of paliperidone palmitate-that case having been reported in a patient randomized to treatment with placebo. Examination of these prospective databases finds no evidence that risperidone LAI and paliperidone palmitate are associated with PDSS and suggest that findings seen with another antipsychotic LAI are not generalizable.

Paliperidone palmitate - review of the efficacy, safety and cost of a new second-generation depot antipsychotic medication.

OBJECTIVE: To describe the efficacy, safety and cost of paliperidone palmitate, a depot antipsychotic medication recently approved for the treatment of schizophrenia. DATA SOURCES: A literature search was conducted by querying the websites http://www.pubmed.gov, http://www.fda.gov, http://www.accessdata.fda.gov/scripts/cder/drugsatfda and http://www.clinicaltrials.gov for the search term 'paliperidone palmitate'. Cost information was obtained from the pharmaceutical vendor servicing a local state-operated psychiatric facility. STUDY SELECTION: All available reports of studies were identified. Product labelling provided additional information. DATA EXTRACTION: Descriptions of the principal results and calculation of the number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the study reports and synopses. Additional safety outcomes subject to NNH analysis were obtained from product labelling. DATA SYNTHESIS: Paliperidone palmitate is a newly available depot formulation of paliperidone (the 9-OH metabolite of risperidone). Upon injection into the deltoid or gluteal muscle, the release of the drug starts as early as day 1, reaches maximum plasma concentrations at 13 days and lasts for as long as 126 days. Maximum concentration following deltoid injection is approximately 28% higher compared with injection into the gluteal muscle, and thus paliperidone palmitate requires initiation by two initial deltoid injections spread 1 week apart to achieve therapeutic concentrations rapidly. Subsequent injections are at 4-week intervals. Acute efficacy was evidenced by four short-term double-blind, randomised, placebo-controlled, fixed-dose studies of acutely relapsed adult inpatients who met DSM-IV criteria for schizophrenia. NNT for a 30% or greater decrease in the Positive and Negative Syndrome Scale total score compared with placebo was consistently lower for the higher dose strengths of 156 and 234 mg, suggesting a therapeutic dose-response. Treatment with paliperidone palmitate at doses between 39 and 156 mg significantly delayed the time to recurrence of symptoms of schizophrenia after 24 weeks of maintained symptom stability. The NNT vs. placebo to avoid a recurrence of symptoms was 5 (95% CI 4-7). Overall, paliperidone palmitate was reasonably well tolerated, with low rates of extrapyramidal symptoms or body weight gain; however, these may be more common at higher doses. Injection site reactions occurred at a rate ranging from 4% to 10%, depending on the dose regimen, compared with 2% for the pooled placebo arms. The acquisition cost of a maintenance dose of paliperidone palmitate calculated on a per day basis is similar to that for risperidone microspheres, but about double the cost for oral paliperidone and approximately 19 times the cost of oral generic risperidone. CONCLUSIONS: Paliperidone palmitate is efficacious for the acute and maintenance treatment of schizophrenia and is reasonably well tolerated. It offers several advantages over other available second-generation depot antipsychotics: it comes in prefilled syringes in a number of different dosage strengths; it does not require refrigeration; it does not require supplementation with oral antipsychotics; it can be administered once monthly; it can be administered with a very small bore needle; the injection volume is small; the injection site can be either the deltoid or gluteal muscles; it does not require an additional precautionary observation period after the injection. For patients for whom oral risperidone or paliperidone is otherwise effective, paliperidone palmitate offers a guaranteed delivery system that enhances adherence. However, the high acquisition cost of paliperidone palmitate will likely be an important obstacle to its routine use.

Assessment in rats of a new bioerodible bone-wax-like polymer.

Holes drilled in rats' skull, iliac crest, and tibia were filled with beeswax or with a new, wax-like, bioerodible polyorthoester (Alzamer). Empty drill-holes served as controls. In addition, beeswax and polyorthoester were deposited between the left and the right oblique abdominal muscles, respectively. In muscle, both the beeswax and polyorthoester elicited a transient foreign body reaction. The beeswax was not resorbed in bone or muscle, whereas the polyorthoester was. Bone healing was inhibited in the iliac crest and the tibiae filled with beeswax, whereas holes filled with polyorthoester healed readily.