The effects of inhibition of fatty acid amide hydrolase (FAAH) by JNJ-42165279 in social anxiety disorder: a double-blind, randomized, placebo-controlled proof-of-concept study.

JNJ-42165279 is a selective inhibitor of fatty acid amide hydrolase (FAAH), the enzyme responsible for the degradation of fatty acid amides (FAA) including anandamide (AEA), palmitoylethanolamide (PEA), and N-oleoylethanolamide (OEA). We assessed the efficacy, safety, tolerability, pharmacokinetics, and pharmacodynamics of treatment with JNJ-42165279 in subjects with social anxiety disorder (SAD). This was a multicenter, double-blind, placebo-controlled study randomizing subjects to 12 weeks of treatment with either JNJ-42165279 (25 mg daily) or placebo (PBO). The primary endpoint was the change in the Liebowitz Social Anxiety Scale (LSAS) total score from baseline to end of study. Secondary endpoints included the Hamilton Anxiety Scale (HAM-A), Hamilton Depression Rating Scale (HDRS17), and the Clinical Global Impression-Improvement (CGI-I). Samples were collected for plasma concentration of AEA, PEA, OEA, and JNJ-42165279. A total of 149 subjects were enrolled with a mean baseline LSAS total score of 102.6 (SD 16.84). The mean change from baseline (SD) in LSAS total score at week 12 was numerically greater for JNJ-42165279: -29.4 (27.47) compared to PBO: -22.4 (23.57) but not significant. The percentage of subjects with ≥30% improvement from baseline in the LSAS total score was significantly higher for JNJ-42165279 (42.4%) compared to PBO (23.6%) (p value = 0.04). The percentage of subjects with a CGI-I score of much or very much improved was also significantly higher for JNJ-42165279 (44.1%) than for PBO (23.6%) (p value = 0.02). The drug was well tolerated. JNJ-42165279 appears to elicit an anxiolytic effect in subjects with SAD although trough concentrations with 25 mg once daily appeared to be insufficient to completely inhibit FAAH activity which may have led to suboptimal efficacy. ClinicalTrials.gov Identifier: NCT02432703.

Correction to: The selective orexin-2 antagonist seltorexant (JNJ-42847922/MIN-202) shows antidepressant and sleep-promoting effects in patients with major depressive disorder.

In the original Article, Tables two and three had formatting issues which affected their clarity. This has been corrected in the PDF and HTML versions of this Article.

The selective orexin-2 antagonist seltorexant (JNJ-42847922/MIN-202) shows antidepressant and sleep-promoting effects in patients with major depressive disorder.

Excessive arousal has a role in the pathophysiology of major depressive disorder (MDD). Seltorexant (JNJ-42847922/MIN-202) is a selective antagonist of the human orexin-2 receptor (OX2R) that may normalize excessive arousal and thereby attenuate depressive symptoms. In this study, the effects of night-time arousal suppression on depressive symptoms were investigated. 47 MDD patients with a total Inventory of Depressive Symptomatology (IDS) score of ≥30 at screening were included in a randomized, double-blind, diphenhydramine-, and placebo-controlled multicentre study. Symptoms of depression were rated using the 17-item Hamilton Depression Rating Scale (HDRS17). Effects on sleep were evaluated by polysomnography and by the Leeds Sleep Evaluation Questionnaire (LSEQ). To investigate the safety and tolerability of seltorexant, vital signs, suicidal ideation and adverse events were monitored. At baseline the severity of depressive symptoms correlated with sleep efficiency (SE), wake after sleep onset (WASO), duration of stage 2 sleep, and ruminations. Ten days of treatment with seltorexant (and not diphenhydramine) resulted in a significant improvement of core depressive symptoms compared to placebo; the antidepressant efficacy of seltorexant was maintained with continued treatment up to 28 days. Compared to placebo, the antidepressant efficacy of seltorexant coincided with an overall increase in (left posterior) EEG power and a relative increase in delta- and decrease in theta-, alpha- and beta power during stage 2 sleep. Treatment with seltorexant was associated with mild, self-limiting adverse drug reactions. Seltorexant affected core symptoms of depression in the absence of overt changes in the hypnogram; in contrast, diphenhydramine was not efficacious.

A pooled analysis evaluating the efficacy and tolerability of tapentadol extended release for chronic, painful diabetic peripheral neuropathy.

BACKGROUND AND OBJECTIVE: Data from two similarly designed studies of tapentadol extended release (ER) for managing neuropathic pain associated with diabetic peripheral neuropathy (DPN; NCT00455520, NCT01041859) in adults were pooled for this analysis, allowing a detailed evaluation of efficacy in patient subgroups and secondary endpoints. METHODS: In each study, patients were titrated to their optimal dose of open-label tapentadol ER [100-250 mg twice daily (bid)] over 3 weeks. Patients with ≥1-point improvement in average pain intensity [11-point numerical rating scale (NRS)] were randomized (1:1) to receive placebo or tapentadol ER during a 12-week, double-blind maintenance period. RESULTS: Mean (standard deviation [SD]) changes in pain intensity from baseline to week 12 of maintenance in the placebo (n = 343) and tapentadol ER (n = 360) groups, respectively, were 1.28 (2.41) and 0.08 (1.87) [least squares mean difference (LSMD): -1.14 (95 % confidence interval [CI]: -1.435, -0.838); P < 0.001, in favour of tapentadol ER]. Significant between-group differences were also observed in changes from the start of the double-blind treatment period to the double-blind endpoint for the Short Form-36 physical functioning, role-physical, bodily pain, social functioning and role-emotional subscale and physical component summary scores, and the EuroQol 5-Dimension health status index (all P < 0.05, in favour of tapentadol ER). No clinically relevant differences were observed in the efficacy of tapentadol ER across patient subgroups divided by age, sex, race, opioid experience and pain intensity. Incidences of treatment-emergent adverse events were 56.0 % (192/343) with placebo and 74.7 % (269/360) with tapentadol ER during maintenance. CONCLUSION: Results of this pooled analysis indicate that tapentadol ER was effective for managing DPN-related pain, and provided consistent analgesic efficacy across different patient subgroups.

Efficacy and safety of oral tapentadol extended release in Japanese and Korean patients with moderate to severe, chronic malignant tumor-related pain.

OBJECTIVE: This phase 3 study evaluated the efficacy and safety of tapentadol extended release (ER) compared with oxycodone controlled release (CR) for the management of moderate to severe, chronic malignant tumor-related cancer pain. RESEARCH DESIGN AND METHODS: This randomized, double-blind, active-controlled study included Japanese and Korean patients with moderate to severe, chronic malignant tumor-related pain. Patients were randomized (1:1) to receive oral tapentadol ER (25-200 mg bid) or oral oxycodone HCl CR (5-40 mg bid) for 4 weeks of double-blind treatment. ClinicalTrials.gov identifier: NCT01165281. MAIN OUTCOME MEASURES: This study was designed to evaluate the non-inferiority of the efficacy provided by tapentadol ER versus oxycodone CR, based on the mean change in average pain intensity (11 point numerical rating scale) from baseline to the last 3 days of study drug administration. Treatment-emergent adverse events (TEAEs) were recorded throughout the study. RESULTS: Of the 374 patients who were screened, 343 were randomized and 236 completed treatment. The least-squares mean difference in the change in pain intensity from baseline to the last 3 days of study treatment between tapentadol ER and oxycodone CR was -0.06 (95% confidence interval [CI], -0.506 to 0.383). The upper limit of the 95% CI was <1 (the predefined threshold value for non-inferiority), indicating that tapentadol ER provided analgesic efficacy that was non-inferior to that of oxycodone CR. The percentage of patients reporting at least one TEAE was similar in the tapentadol ER (87.5% [147/168]) and oxycodone CR (90.1% [155/172]) treatment groups, but the incidence of gastrointestinal TEAEs was lower in the tapentadol ER group (55.4% [93/168]) than in the oxycodone CR group (67.4% [116/172]). CONCLUSIONS: Tapentadol ER (25-200 mg bid) provides analgesic efficacy that is non-inferior to that provided by oxycodone HCl CR (5-40 mg bid) for the management of moderate to severe, chronic malignant tumor-related pain, and is well tolerated overall, with a better gastrointestinal tolerability profile than oxycodone CR.

Efficacy and safety of Tapentadol extended release compared with oxycodone controlled release for the management of moderate to severe chronic pain related to osteoarthritis of the knee: a randomized, double-blind, placebo- and active-controlled phase III study.

BACKGROUND: Tapentadol is a novel, centrally acting analgesic with mu-opioid receptor agonist and norepinephrine reuptake inhibitor activity. OBJECTIVE: to evaluate the efficacy and safety of Tapentadol extended release (ER) compared with oxycodone controlled release (CR) for management of moderate to severe chronic osteoarthritis-related knee pain. METHODS: this was a randomized, double-blind, active- and placebo-controlled, parallel-arm, multicentre, phase III study during which patients received Tapentadol ER, oxycodone CR or placebo for a 3-week titration period followed by a 12-week maintenance period. The study was carried out at sites in Australia, Canada, New Zealand and the US. A total of 1030 patients with chronic osteoarthritis-related knee pain were randomized to receive Tapentadol ER 100-250 mg twice daily, oxycodone HCl CR 20-50 mg twice daily or placebo. Primary endpoints (as determined prior to initiation of the study) were the changes from baseline in average daily pain intensity (rated by patients on an 11-point numerical rating scale) over the last week of maintenance and over the entire 12-week maintenance period; last observation carried forward was used to impute missing values after early treatment discontinuation. RESULTS: efficacy and safety were evaluated for 1023 patients. Tapentadol ER significantly reduced average pain intensity from baseline to week 12 of the maintenance period versus placebo (least squares mean [LSM] difference [95% CI], -0.7 [-1.04, -0.33]), and throughout the maintenance period (-0.7 [-1.00, -0.33]). Oxycodone CR significantly reduced average pain intensity from baseline throughout the maintenance period versus placebo (LSM difference [95% CI], -0.3 [-0.67, -0.00]) but not at week 12 (-0.3 [-0.68, 0.02]). A significantly higher percentage of patients achieved > or =50% improvement in pain intensity in the Tapentadol ER group (32.0% [110/344]) compared with the placebo group (24.3% [82/337]; p = 0.027), indicating a clinically significant improvement in pain intensity, while a significantly lower percentage of patients achieved > or =50% improvement in pain intensity in the oxycodone CR group (17.3% [59/342]; p = 0.023 vs placebo). In the placebo, Tapentadol ER and oxycodone CR groups, respectively, 61.1% (206/337), 75.9% (261/344) and 87.4% (299/342) of patients reported at least one treatment-emergent adverse event (TEAE); incidences of gastrointestinal-related TEAEs were 26.1% (88/337), 43.0% (148/344) and 67.3% (230/342). CONCLUSION: treatment with Tapentadol ER 100-250 mg twice daily or oxycodone HCl CR 20-50 mg twice daily was effective for the management of moderate to severe chronic osteoarthritis-related knee pain, with substantially lower incidences of gastrointestinal-related TEAEs associated with treatment with Tapentadol ER than with oxycodone CR.

Efficacy and safety of tapentadol extended release for the management of chronic low back pain: results of a prospective, randomized, double-blind, placebo- and active-controlled Phase III study.

OBJECTIVE: To evaluate the efficacy and safety of tapentadol extended release (ER) for the management of moderate to severe chronic low back pain. RESEARCH DESIGN: Patients (N = 981) were randomized 1:1:1 to receive tapentadol ER 100 - 250 mg b.i.d., oxycodone HCl controlled release (CR) 20 - 50 mg b.i.d., or placebo over 15 weeks (3-week titration period, 12-week maintenance period). MAIN OUTCOME MEASURES: Efficacy was assessed as change from baseline in average pain intensity (11-point NRS) at week 12 of the maintenance period and throughout the maintenance period; last observation carried forward was used to impute missing pain scores. Adverse events (AEs) were monitored throughout the study. RESULTS: Tapentadol ER significantly reduced average pain intensity versus placebo at week 12 (least squares mean difference vs placebo [95% confidence interval], -0.8 [-1.22, -0.47]; p < 0.001) and throughout the maintenance period (-0.7 [-1.06,-0.35]; p < 0.001). Oxycodone CR significantly reduced average pain intensity versus placebo at week 12 (-0.9 [-1.24,-0.49]; p < 0.001) and throughout the maintenance period (-0.8 [-1.16,-0.46]; p < 0.001). Tapentadol ER was associated with a lower incidence of treatment-emergent AEs (TEAEs) than oxycodone CR. Gastrointestinal TEAEs, including constipation, nausea, and vomiting, were among the most commonly reported TEAEs (placebo, 26.3%; tapentadol ER, 43.7%; oxycodone CR, 61.9%). The odds of experiencing constipation or the composite of nausea and/or vomiting were significantly lower with tapentadol ER than with oxycodone CR (both p < 0.001). CONCLUSIONS: Tapentadol ER (100 - 250 mg b.i.d.) effectively relieved moderate to severe chronic low back pain over 15 weeks and had better gastrointestinal tolerability than oxycodone HCl CR (20 - 50 mg b.i.d.).

Risperidone for the treatment of acute mania in children and adolescents with bipolar disorder: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: To evaluate the efficacy, safety, and tolerability of risperidone monotherapy for the treatment of an acute mixed or manic episode in children and adolescents with bipolar I disorder. METHODS: This randomized, placebo-controlled, double-blind, 3-arm study (N = 169) included children and adolescents (ages 10-17 years) with a DSM-IV diagnosis of bipolar I disorder, experiencing a manic or mixed episode. Study participants were randomized to placebo (n = 58), risperidone 0.5-2.5 mg/day (n = 50), or risperidone 3-6 mg/day (n = 61) for 3 weeks. The primary efficacy measure was change in Young Mania Rating Scale (YMRS) total score from baseline to end point. Safety assessments included adverse event (AE) monitoring and scores on extrapyramidal symptom rating scales. RESULTS: Improvement in mean YMRS total score was significantly greater in risperidone-treated subjects than in placebo-treated subjects [mean change (SD) -9.1 (11.0) for placebo; -18.5 (9.7) for risperidone 0.5-2.5 mg (p < 0.001); -16.5 (10.3) for risperidone 3-6 mg (p < 0.001)]. The most common risperidone-associated AEs were somnolence, headache, and fatigue. Mean (SD) weight gain was 0.7 (1.9) kg, 1.9 (1.7) kg, and 1.4 (2.4) kg in the placebo, risperidone 0.5-2.5 mg, and risperidone 3-6 mg groups, respectively, during this 3-week study. CONCLUSIONS: At daily doses of 0.5-2.5 mg and 3-6 mg, risperidone was effective and well tolerated in children and adolescents experiencing acute manic or mixed episodes of bipolar I disorder. Results indicate that risperidone 0.5-2.5 mg has a better benefit-risk profile than risperidone 3-6 mg.

Efficacy and tolerability of tapentadol immediate release and oxycodone HCl immediate release in patients awaiting primary joint replacement surgery for end-stage joint disease: a 10-day, phase III, randomized, double-blind, active- and placebo-controlled study.

OBJECTIVES: The primary objective of this study was to assess the efficacy and tolerability of tapentadol immediate release (IR) in patients who were candidates for joint replacement surgery due to end-stage joint disease. A secondary objective was to compare tapentadol IR with oxycodone HCl IR with respect to efficacy and prespecified tolerability end points. METHODS: This 10-day, Phase III, randomized, double-blind, active- and placebo-controlled study compared the efficacy and tolerability of tapentadol IR, oxycodone HCl IR, and placebo in patients with uncontrolled osteoarthritis pain who were candidates for primary replacement of the hip or knee as a result of end-stage degenerative joint disease. Patients received tapentadol IR 50 mg, tapentadol IR 75 mg, oxycodone HCl IR 10 mg, or placebo every 4 to 6 hours during waking hours. The primary end point was the sum of pain intensity difference (SPID) over 5 days. Secondary efficacy end points included 2- and 10-day SPID; 2-, 5-, and 10-day total pain relief (TOTPAR); and the sum of total pain relief and pain intensity difference (SPRID). Prespecified noninferiority comparisons with oxycodone HCl IR were performed with respect to efficacy (based on 5-day SPID) and tolerability (based on incidence of the reported adverse events (AEs) of nausea and/or vomiting and constipation). RESULTS: Of 666 patients originally enrolled, 659 were included in the efficacy analysis (51% male; 91% white; mean age, 61.2 years; mean weight, 97 kg). Five-day SPID was significantly lower in those treated with tapentadol IR (tapentadol IR 50 mg: least squares mean difference [LSMD] = 101.2 [95% CI, 54.58- 147.89]; tapentadol IR 75 mg: LSMD = 97.5 [95% CI, 51.81-143.26]) or oxycodone HCl IR (LSMD = 111.9 [95% CI, 66.49-157.38]) (all, P < 0.001). Tapentadol IR 50 and 75 mg and oxycodone HCl IR 10 mg were associated with significant reductions in pain intensity compared with placebo, based on 2- and 10-day SPID and 2-, 5-, and 10-day TOTPAR and SPRID (all, P < 0.001). The efficacy of tapentadol IR 50 and 75 mg was noninferior to that of oxycodone HCl IR 10 mg; however, the incidence of selected gastrointestinal AEs (nausea, vomiting, and constipation) was significantly lower for both doses of tapentadol IR compared with oxycodone HCl IR 10 mg (nominal P < 0.001). The odds ratios for nausea and/or vomiting for tapentadol IR 50 and 75 mg relative to oxycodone HCl IR 10 mg were 0.21 (95% CI, 0.128-0.339) and 0.32 (95% CI, 0.204-0.501), respectively; for constipation, the corresponding odds ratios were 0.13 (95% CI, 0.057-0.302) and 0.20 (95% CI, 0.098-0.398). Rates of treatment discontinuation were 18% (28/157) in the tapentadol IR 50-mg group, 26% (43/168) in the tapentadol IR 75-mg group, 35% (60/172) in the oxycodone HCl IR 10-mg group, and 10% (17/169) in the placebo group. In a post hoc analysis, tapentadol IR 50 mg was associated with a significantly lower incidence of treatment discontinuation than was oxycodone HCl IR 10 mg (P < 0.001). CONCLUSIONS: In these patients with uncontrolled osteoarthritis pain who were awaiting joint replacement surgery, tapentadol IR 50 and 75 mg were associated with analgesia that was noninferior to that provided by oxycodone HCl IR 10 mg. Tapentadol treatment was associated with improved gastrointestinal tolerability.

Long-term safety and tolerability of long-acting injectable risperidone in patients with schizophrenia or schizoaffective disorder.

Subjects were patients with schizophrenia or schizoaffective disorder enrolled in extension studies (Study A and Study B) after participating in 12-week studies of long-acting injectable risperidone [Kane, J.M., Eerdekens, M., Lindenmayer, J.-P., Keith, S.J., Lesem, M., Karcher, K., 2003. Long-acting injectable risperidone: efficacy and safety of the first long-acting atypical antipsychotic. Am. J. Psychiatry 160, 1125-1132; Lindenmayer, J.-P., Eerdekens, L., Berry, S., Eerdekens, M., 2004. Safety and efficacy of long-acting risperidone in schizophrenia: a 12-week, multicenter, open-label study in stable patients switched from typical and atypical oral antipsychotics. J. Clin. Psychiatry 65, 1084-1089]. Twelve months of treatment were completed by 55% of Study A patients and 52% of Study B patients. The median modal dose of long-acting injectable risperidone was 50 mg/14 days in both studies. Most frequent adverse events were psychosis, headache, insomnia, agitation, and rhinitis. EPS-related adverse events were reported in 33% of patients in Study A and 22% in Study B. Patients with Clinical Global Impressions ratings of "not ill" and "mild" increased from 14% at baseline to 54% at endpoint in Study A and from 42% to 65% in Study B. It is concluded that treatment with long-acting injectable risperidone for 1 year or longer appeared to be safe and well tolerated in patients with schizophrenia or schizoaffective disorder.

Risperidone in the treatment of psychosis of Alzheimer disease: results from a prospective clinical trial.

OBJECTIVE: The objective of this study was to evaluate efficacy and safety of low-dose risperidone for treating psychosis of Alzheimer disease (AD). METHOD: The authors conducted a randomized, eight-week, double-blind, placebo-controlled, multicenter trial involving nursing home residents diagnosed with AD and psychosis. Four hundred seventy-three patients were randomly assigned to placebo (N = 238) or 1.0 to 1.5 mg risperidone per day (N = 235). Coprimary efficacy end points were: changes in scores on the Behavioral pathology in Alzheimer's Disease (BEHAVE-AD) Psychosis subscale and Clinical Global Impression of Change (CGI-C). Protocol-specified subgroup analyses were performed by demographics and dementia severity. RESULTS: Efficacy analysis included 416 patients. Both groups improved significantly on the BEHAVE-AD Psychosis subscale and CGI-C with no significant difference between groups. In the subgroups analyses, a statistically significant treatment by Mini-Mental Status Examination (MMSE) interaction on the CGI-C (F([2,381]) = 3.90, p = 0.021) was observed with patients with more severe dementia (MMSE <10) showing significant differences at end point favoring risperidone treatment (chi(2) ([1]) = 5.11, p = 0.024). Mean risperidone dose was 1.03 +/- 0.24 mg per day. All-cause discontinuation rates were 25% for both risperidone and placebo. Treatment-emergent adverse events occurred in 74% risperidone versus 64% placebo patients, with somnolence occurring significantly more frequently with risperidone (16.2% versus 4.6%). Nine (3.8%) risperidone- and six (2.5%) placebo patients died during or within 30 days after treatment. CONCLUSION: This trial did not confirm earlier findings in this population.

Risperidone and haloperidol in first-episode psychosis: a long-term randomized trial.

OBJECTIVE: The first episode of psychotic illness is a key intervention point. The initial experience with medication can affect willingness to accept treatment. Further, relapse prevention is a treatment cornerstone during the first years of illness because active psychotic illness may affect lifetime outcomes. Thus, initial treatment of active symptoms and subsequent relapse prevention are central goals of pharmacotherapy. This study compared long-term effectiveness of risperidone versus haloperidol in first-episode psychosis patients. METHOD: First-episode psychosis patients (N=555, mean age=25.4 years) participated in a double-blind, randomized, controlled flexible-dose trial that compared risperidone (mean modal dose=3.3 mg) and haloperidol (mean modal dose=2.9 mg). The median treatment length was 206 days (maximum=1,514). RESULTS: Positive and Negative Syndrome Scale scores and Clinical Global Impression ratings improved significantly relative to baseline, with no significant differences between groups. Three-quarters of the patients achieved initial clinical improvement, defined as >20% reduction in total Positive and Negative Syndrome Scale score. However, among those who achieved clinical improvement, 42% of the risperidone group experienced a relapse compared with 55% of the haloperidol group. The median time to relapse was 466 days for risperidone-treated subjects and 205 days for those given haloperidol. These differences were statistically significant based on Kaplan-Meier survival analysis. Adverse effects distinguished the treatments: there were significantly more extrapyramidal signs and symptoms and adjunctive medication use in the haloperidol group and greater prolactin elevation in the risperidone group. There was less weight gain with haloperidol initially but no significant differences between groups at endpoint. CONCLUSIONS: Relatively low doses of antipsychotic drugs lead to significant symptom amelioration in the majority of first-episode psychosis patients. In the long term, risperidone prevents relapse in more patients and for a longer time and also induces less abnormal movements than haloperidol.

Short- and long-term efficacy and safety of risperidone in adults with disruptive behavior disorders.

RATIONALE: Function in society can be severely affected by disruptive behaviors in adults. OBJECTIVES: To examine the efficacy and safety of risperidone in the treatment of disruptive behavior disorders in intellectually disabled adults. METHODS: Intellectually disabled patients with disruptive behavior disorder were randomly assigned to receive risperidone (n = 39) in a flexible dosage ranging from 1 to 4 mg/day (mean dosage, 1.45+/-0.08 mg/day) or placebo (n = 38) for 4 weeks of double-blind treatment. Efficacy at endpoint was measured primarily by using the Aberrant Behavior Checklist (ABC); secondary efficacy measures included the Behavior Problems Inventory and Clinical Global Impressions scales. After this 4-week period, patients could enter open-label treatment with risperidone for 48 weeks. RESULTS: Risperidone was well tolerated, and patients treated with risperidone demonstrated significantly greater improvement at endpoint on the ABC than those who received placebo [-27.3 points (52.8% improvement) versus -14.9 points (31.3% improvement); P = 0.036] and also improved on Behavior Problems Inventory and Clinical Global Impressions ratings. Over the 48-week, open-label follow-up period, there was a further decrease of 6.3 points (P < or = 0.05) on the ABC for patients who initially received risperidone and a decrease of 11.3 points (P < or = 0.05) for patients who initially received placebo and were switched to open-label risperidone. These results were achieved with a mean modal dosage of 1.8 mg/day. CONCLUSION: Risperidone is efficacious and well tolerated in managing disruptive behavior disorders in adults with intellectual disability.

Pharmacokinetics and tolerability of long-acting risperidone in schizophrenia.

The pharmacokinetics and tolerability of long-acting risperidone (Risperdal Consta) were evaluated in a multicenter, prospective, open-label, 15-week study of 86 patients with schizophrenia. Subjects stabilized on 2, 4 or 6 mg of oral risperidone once daily for at least 4 weeks were assigned to receive i.m. injections of 25, 50 or 75 mg of risperidone, respectively, every 2 weeks for 10 weeks. The 90% confidence intervals for the i.m./oral ratios of the mean steady-state plasma-AUC, corrected for dosing interval, and of the average plasma concentration of the active moiety (risperidone plus 9-hydroxyrisperidone) were within the range of 80-125%, indicating bioequivalence of the i.m. and oral formulations. However, mean steady-state peak concentrations of the active moiety were 25-32% lower with i.m. than oral dosing (P < 0.05) and fluctuations in plasma active-moiety levels were 32-42% lower with the i.m. than oral regimen. Symptoms of schizophrenia continued to improve after switching from oral to i.m. dosing. Long-acting risperidone was well tolerated locally and systematically. Although overall bioequivalence of the two formulations was established, the differences in pharmacokinetic profiles between the two formulations indicate potential benefits for long-acting risperidone.