Pharmacokinetic Drug-Drug Interaction With Coadministration of Cannabidiol and Everolimus in a Phase 1 Healthy Volunteer Trial

When highly purified cannabidiol (CBD; Epidiolex) and the mammalian target of rapamycin inhibitor everolimus are used concomitantly in the treatment of tuberous sclerosis complex, there is evidence of a pharmacokinetic (PK) interaction, leading to increased everolimus systemic exposure. We evaluated the effect of steady-state CBD exposure following multiple clinically relevant CBD doses on everolimus PK in healthy adult participants in a single-center, fixed-sequence, open-label, phase 1 study. All participants received oral everolimus 5 mg on day 1, followed by a 7-day washout. On days 9-17, participants received CBD (100 mg/mL oral solution) at 12.5 mg/kg in the morning and evening. On the morning of day 13, participants also received a single dose of oral everolimus 5 mg. Medications were taken 30 or 45 minutes (morning or evening dose) after starting a standardized meal. Maximum concentration and area under the concentration-time curve (AUC) from time of dosing to the last measurable concentration and extrapolated to infinity, of everolimus in whole blood were estimated using noncompartmental analysis, with geometric mean ratios and 90% confidence intervals for the ratios of everolimus dosed with CBD to everolimus dosed alone. A single dose of everolimus 5 mg was well tolerated when administered with multiple doses of CBD. Log-transformed everolimus maximum concentration, AUC from time of dosing to the last measurable concentration, and AUC extrapolated to infinity values increased by ≈2.5-fold, and everolimus half-life remained largely unchanged in the presence of steady-state CBD relative to everolimus dosed alone. Everolimus blood concentration monitoring should be strongly advised with appropriate dose reduction when coadministered with CBD.

Development of an integrated conceptual model of multiple sclerosis spasticity

PURPOSE

Spasticity is common in multiple sclerosis (MS), often leading to functional limitations and disability. We developed a conceptual model of spasticity in MS integrating expert opinion, recent literature, and experiences of clinicians and people with MS spasticity.

METHODS

A conceptual model was developed based on a targeted literature review of articles published between 2014 and 2019, followed by input from clinicians, then input from participants with MS spasticity. Multidisciplinary experts on spasticity provided guidance at each step.

RESULTS

Key concepts of the integrated spasticity conceptual model included: moderators; triggers; modifiers; treatment; objective manifestations; subjective experience; physical, functional, social, and emotional/psychological impacts; and long-term consequences. Participants with MS spasticity most frequently endorsed spasms, tightness, and pain as descriptors of spasticity. Some participants with MS spasticity had difficulty distinguishing spasticity from other MS symptoms (e.g. muscle weakness). Some triggers, emotional/psychological impacts, and long-term consequences of spasticity reported by participants with MS spasticity were not previously identified in the published literature.

CONCLUSIONS

This conceptual model of spasticity, integrating published literature with the experience of clinicians, people with MS spasticity, and experts, demonstrates the complex, multidimensional nature of MS spasticity. This model may be used to improve clinician-patient dialogue, research, and patient care.

Efficacy of nabiximols oromucosal spray on spasticity in people with multiple sclerosis: Treatment effects on Spasticity Numeric Rating Scale, muscle spasm count, and spastic muscle tone in two randomized clinical trials

BACKGROUND

To provide a comprehensive assessment of the treatment effects of nabiximols oromucosal spray on multiple sclerosis spasticity in two clinical trials, GWSP0604 and SAVANT.

METHODS

Both studies enriched for responders before randomization, defined by a ≥20% improvement in Spasticity 0-10 numeric rating scale (NRS) score. Additionally, SAVANT used randomized re-titration following washout. Spasticity NRS outcomes, spasm count, and modified Ashworth scale (MAS) scores were analyzed.

RESULTS

Mean change from baseline in average daily Spasticity NRS scores was significantly larger for nabiximols than placebo at all postbaseline timepoints, ranging from -0.36 to -0.89 in GWSP0604 and -0.52 to -1.96 in SAVANT. Percent reduction in geometric mean change from baseline in average daily spasm count for nabiximols ranged from 19-35% versus placebo. A treatment difference favoring nabiximols was observed in overall MAS scores during the randomized part of each study. Treatment effect was larger for combinations of lower limb muscle groups (ranging between -0.16 and -0.37).

CONCLUSIONS

Nabiximols leads to improvement in spasticity that was sustained over the 12-week treatment period as measured by average daily Spasticity NRS scores, daily spasm counts, and MAS scores for combinations of muscle groups, especially the combination of the 6 key muscle groups in the lower limbs in NRS responders to nabiximols treatment.

Metabolism and disposition of JNJ-10450232 (NTM-006) in rats, dogs, nonhuman primates and humans

JNJ-10450232 (NTM-006), a novel non-opioid, non-nonsteroidal anti-inflammatory drug with structural similarities to acetaminophen, demonstrated anti-pyretic and/or analgesic activities in preclinical models and humans and reduced potential to cause hepatotoxicity in preclinical species. Metabolism and disposition of JNJ-10450232 (NTM-006) following oral administration to rats, dogs, monkeys and humans are reported. Urinary excretion was the major route of elimination based on recovery of 88.6% (rats) and 73.7% (dogs) of oral dose. The compound was extensively metabolized based on low recovery of unchanged drug in excreta from rats (11.3%) and dogs (18.4%). Clearance is driven by O-glucuronidation, amide hydrolysis, O-sulfation and methyl oxidation pathways. The combination of metabolic pathways driving clearance in human is covered in at least one preclinical species despite a few species-dependent pathways. O-Glucuronidation was the major primary metabolic pathway of JNJ-10450232 (NTM-006) in dogs, monkeys and humans, although amide hydrolysis was another major primary metabolic pathway in rats and dogs. A minor bioactivation pathway to quinone-imine is observed only in monkeys and humans. Unchanged drug was the major circulatory component in all species investigated. Except for metabolic pathways unique to the 5-methyl-1H-pyrazole-3-carboxamide moiety, metabolism and disposition of JNJ-10450232 (NTM-006) are similar to acetaminophen across species.

A phase 1, randomized, pharmacokinetic trial of the effect of different meal compositions, whole milk, and alcohol on cannabidiol exposure and safety in healthy subjects

OBJECTIVE

The pharmacokinetics (PK) and safety of single oral 750-mg doses of a plant-derived pharmaceutical formulation of highly purified cannabidiol (CBD; Epidiolex in the USA and Epidyolex in Europe; 100-mg/mL oral solution) were assessed in healthy adults following a high-fat/calorie meal (n = 15), a low-fat/calorie meal (n = 14), whole milk (n = 15), or alcohol (n = 14), relative to the fasted state (n = 29).

METHODS

Blood samples were collected until 96 hours postdose in each period and evaluated by liquid chromatography and tandem mass spectrometry. PK parameters (maximum observed plasma concentration [C_max ], area under the plasma concentration-time curve from time zero to the last observed quantifiable concentration, area under the concentration-time curve from time zero to infinity [AUC_0-∞ ], and time to maximum plasma concentration [t_max ]) of CBD and its major metabolites were derived using noncompartmental analysis.

RESULTS

CBD exposure increased by 3.8-fold for AUC_0-∞ and 5.2-fold for C_max when CBD was administered with a high-fat/calorie meal versus fasted. To a lesser extent, a low-fat/calorie meal enhanced CBD exposure versus fasted with a 2.7-fold increase in AUC_0-∞ and a 3.8-fold increase in C_max . Similarly, when dosed with whole milk, CBD exposure increased versus fasted by 2.4-fold for AUC_0-∞ and 3.1-fold for C_max . Modest elevations in CBD exposure occurred when it was dosed with alcohol: 1.6-fold for AUC_0-∞ and 1.9-fold for C_max . No clinically relevant effect of any test condition on CBD t_max or t_½ versus the fasted state was apparent. The same trend was seen for the CBD metabolites, except that 7-carboxy-cannabidiol t_max was considerably longer when CBD was administered with alcohol (14 vs 4 hours fasted). Inter- and intrasubject variability in PK parameters was moderate to high during the trial.

SIGNIFICANCE

CBD and metabolite exposures were most affected by a high-fat/calorie meal. CBD exposures also increased with a low-fat/calorie meal, whole milk, or alcohol, but to a lesser extent. CBD was tolerated, and there were no severe or serious adverse events during the trial.

Does Half-Life Matter After Antipsychotic Discontinuation? A Relapse Comparison in Schizophrenia With 3 Different Formulations of Paliperidone

OBJECTIVE

To evaluate the effect of 1 oral and 2 distinct long-acting injectable (LAI) formulations of the same antipsychotic on times to relapse following medication discontinuation.

METHODS

Data were drawn from 3 similarly designed, multicenter, double-blind, placebo-controlled, randomized-withdrawal studies of paliperidone in adults with a schizophrenia diagnosis (according to DSM-IV criteria for ≥ 1 year before screening): once-daily extended-release oral paliperidone (ORAL paliperidone), once-monthly paliperidone palmitate (PP1M), and once-every-3-months paliperidone palmitate (PP3M). In a post hoc analysis, we compared median time to relapse across the treatment-withdrawal arms of the 3 studies using final analysis datasets. Time to relapse in the withdrawal arm of each study was examined using log-rank tests and Cox proportional hazards models.

RESULTS

Four hundred forty-nine patients were withdrawn from 3 paliperidone formulations: 101 from ORAL paliperidone, 203 from PP1M, and 145 from PP3M. Postwithdrawal median (95% confidence interval [CI]) days to relapse were 58 days (42-114 days) for ORAL paliperidone, 172 days (134-222 days) for PP1M, and 395 days (274 days-not reached) for PP3M (P < .0001, pairwise comparisons). Relapse risk was significantly lower (P < .001) for patients who withdrew from either PP formulation relative to ORAL paliperidone and additionally for patients who withdrew from PP3M relative to PP1M.

CONCLUSIONS

Results demonstrate that 50% of patients who withdrew treatment from ORAL paliperidone, PP1M, or PP3M remained relapse free for approximately 2 months, 6 months, and 13 months, respectively. This may be relevant for risk mitigation strategies in schizophrenia, a condition in which interruptions in maintenance antipsychotic treatment are commonplace and unpredictable. LAI antipsychotic formulations may provide substantial delays over oral equivalents in times to relapse when patients discontinue therapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT00086320, NCT00111189, and NCT01529515.

Practical guidance for dosing and switching from paliperidone palmitate 1 monthly to 3 monthly formulation in schizophrenia

OBJECTIVE

This commentary summarizes recommended dosing strategies for a recently developed 3 monthly long-acting injectable 1 (LAI) formulation of paliperidone palmitate (PP3M) for the treatment of schizophrenia in adults.

METHODS

Recommendations for different dosing scenarios are based on the pharmacokinetic, efficacy and safety outcomes from phase 1 and phase 3 studies, population pharmacokinetic models, and model based simulations.

RESULTS

Switching to PP3M treatment is recommended only in patients previously treated with once monthly paliperidone palmitate LAI (PP1M) for at least 4 months. The first injection of PP3M (175 to 525 mg equivalent [eq.]) should be given at the time of next scheduled injection of PP1M as a 3.5-fold multiple of the last PP1M dose (50-150 mg eq.), with a dosing window of ± 1 week. Following that first injection of PP3M, once-every-three-months maintenance injections with PP3M are recommended, with a dosing window of ± 2 weeks. The doses of PP3M can be administered in either deltoid (≥ 90 kg: 1.5 inch 22 G needle; <90 kg: 1.0 inch 22 G needle) or gluteal muscles (1.5 inch 22 G needle regardless of weight). In patients with mild renal impairment (creatinine clearance: 50-80 mL/min), a 25% dose reduction in PP1M and subsequent switching to a corresponding 3.5-dose multiple of PP3M (but not exceeding 350 mg eq.) is recommended. Appropriate dosing is recommended in elderly patients with diminished renal function not exceeding mild renal impairment. Similarly to PP1M, PP3M is not recommended in patients with moderate/severe renal impairment. Like PP1M, no dosage adjustment is required in patients with mild or moderate hepatic impairment or elderly patients with normal renal function.

CONCLUSIONS

These data provide clinical guidelines for the optimum use of PP3M in patients with schizophrenia previously treated with PP1M for at least 4 months.

REGISTRATION

ClinicalTrials.gov identifier: NCT01559272 and NCT01529515.

Efficacy and Safety of the 3-Month Formulation of Paliperidone Palmitate vs Placebo for Relapse Prevention of Schizophrenia: A Randomized Clinical Trial

IMPORTANCE

Treatment nonadherence and relapse are common problems in patients with schizophrenia. The long-acting 3-month formulation of paliperidone palmitate, owing to its extended elimination half-life, may offer a valuable therapeutic option for these patients.

OBJECTIVE

To evaluate the efficacy and safety of the 3-month formulation of paliperidone palmitate vs placebo in delaying time to relapse of schizophrenia symptoms.

DESIGN, SETTING, AND PARTICIPANTS

This randomized, multicenter trial conducted from April 26, 2012, through April 9, 2014, in 8 countries consisted of 4 phases: 3-week screening phase, flexible-dose 17-week open-label transition phase, 12-week open-label maintenance phase, and open-ended double-blind (DB) phase. Of the 506 patients enrolled (aged 18-70 years; DSM-IV-TR diagnosis of schizophrenia), 305 were randomized to 3-month paliperidone palmitate (n = 160) or placebo (n = 145) in the DB phase.

INTERVENTIONS

Patients received once-monthly doses of the 1-month formulation of paliperidone palmitate (50, 75, 100, or 150 mg eq) during the transition phase, followed by a single dose of the 3-month formulation (3.5 times the stabilized dose of once-monthly paliperidone palmitate) during the maintenance phase. Stabilized patients were randomized to receive either a fixed dose of 3-month paliperidone palmitate (175, 263, 350, or 525 mg eq) or placebo once every 3 months during the DB phase.

MAIN OUTCOMES AND MEASURES

Time from randomization to the first relapse event (time to relapse) in the DB phase.

RESULTS

In the interim analysis, time to first relapse was significantly different in favor of the paliperidone palmitate group vs the placebo group (hazard ratio = 3.45; 95% CI, 1.73-6.88; P < .001); median time to relapse was 274 days for placebo but not estimable for 3-month paliperidone palmitate. An independent data monitoring committee recommended early study termination due to efficacy. In the DB phase, 183 of 305 patients (62% with 3-month paliperidone palmitate; 58% with placebo) had at least 1 treatment-emergent adverse event; those noted more frequently in the group receiving paliperidone palmitate than in the placebo group were headache (9% vs 4%), weight increased (9% vs 3%), nasopharyngitis (6% vs 1%), and akathisia (4% vs 1%).

CONCLUSIONS AND RELEVANCE

Compared with placebo, the 3-month formulation of paliperidone palmitate administered 4 times yearly significantly delayed time to relapse in patients with schizophrenia. The 3-month formulation was generally tolerable and has a safety profile consistent with other marketed paliperidone formulations.

TRIAL REGISTRATION

clinicaltrials.gov Identifier:NCT01529515.

Doctor shopping for medications used in the treatment of attention deficit hyperactivity disorder: shoppers often pay in cash and cross state lines

BACKGROUND

Doctor shopping, defined by filling overlapping prescriptions from more than one prescriber at more than two pharmacies, is a way to obtain scheduled medications for diversion or abuse. Little is known about how far attention deficit hyperactivity disorder (ADHD) medication shoppers travel, how often they cross state lines to fill their ADHD prescriptions and how often they pay for their medication in cash, i.e. entirely out of pocket.

OBJECTIVE

We sought to describe the pattern of doctor shopping for ADHD medications: how far shoppers travel, how often they cross state lines to fill their prescriptions, and how often they pay in cash.

METHODS

Retrospective cohort study using LRx, a large US retail prescription database. We included subjects with any ADHD medication dispensed between 2011 and 2012. Subjects were followed for 18 months.

RESULTS

Of a total of 4 402 464 subjects exposed to ADHD medications, 0.4% developed shopping behavior. Women were more likely to become shoppers. Shoppers travelled a median of 91.9 miles and non-shoppers 0.2 miles to fill their ADHD prescriptions. Almost 28% of the shoppers filled prescriptions in >1 state compared with 4.3% of non-shoppers. Of the shoppers, 27.3% paid at least one prescription in cash compared to 14.4% of the non-shoppers.

CONCLUSIONS

Shoppers travelled larger distances, visited more states and paid in cash for ADHD medications more often than non-shoppers. Data sharing among prescriptions monitoring programs can improve their effectiveness and drug utilization studies should take account of cash purchases.

A single-dose, open-label, parallel, randomized, dose-proportionality study of paliperidone after intramuscular injections of paliperidone palmitate in the deltoid or gluteal muscle in patients with schizophrenia

Paliperidone palmitate (PP) is a long-acting injectable (LAI) antipsychotic, developed for monthly intramuscular (i.m.) administration into deltoid/gluteal muscle, approved for the treatment of schizophrenia in many countries. To assess the options for i.m. injection sites, dose-proportionality of PP was investigated after injection of a single dose (25-150 mg eq.) of PP in either gluteal (n = 106) or deltoid (n = 95) muscle of schizophrenic patients. Overall, mean (geometric) area under plasma concentration-time curve from time zero to infinity (AUC∞ ) of paliperidone increased proportionally with increasing PP doses, regardless of injection site. Mean maximum plasma concentration (Cmax ) was slightly less than dose-proportional for both injection sites at PP doses >50 mg eq. Mean Cmax was higher after injection in the deltoid compared with the gluteal muscle, except for the 100 mg eq. dose, while AUC∞ for both injection sites was comparable at all doses. Median time to reach Cmax (tmax ) ranged from 13-14 days after deltoid and 13-17 days after gluteal injection across all doses. Single PP injections in deltoid and gluteal muscles in the dose range of 25-150 mg eq. were generally tolerable both locally and systemically.

Limited utility of number needed to treat and the polarity index for bipolar disorder to characterize treatment response

The medical community increasingly supports the use of simplifying constructs or ratios to facilitate incorporation of evidence-based medicine into clinical practice such as number needed to treat (NNT) and polarity index (PI). Clinicians and teachers find them to be an appealing, easy-to remember integer that can be readily translated into clinical practice. However, serious questions have been raised with respect to the validity, reliability and value of these descriptors of response. This commentary identifies some of the specific limitations of the NNT and PI constructs when applied to treatments of bipolar disorder.

Efficacy and safety of prolonged-release OROS methylphenidate in adults with attention deficit/hyperactivity disorder: a 13-week, randomized, double-blind, placebo-controlled, fixed-dose study

OBJECTIVES

Methylphenidate (MPH) is effective for adults with attention-deficit/hyperactivity disorder (ADHD). This study aimed to evaluate the efficacy and safety of OROS MPH in adults with ADHD.

METHODS

Randomized, double-blind study; 279 subjects received OROS MPH 54 or 72 mg/day, or placebo, for 13 weeks. Primary endpoint was the Conners' Adult ADHD Rating Scale - Screening Version (CAARS-O:SV). Secondary outcomes included CAARS Self Report - Short Version (CAARS-S:S), Sheehan Disability Scale (SDS) and ADHD Impact Module - Adult (AIM-A).

RESULTS

Improvements in CAARS-O:SV were significantly greater with OROS MPH 72 mg vs. placebo (P = 0.0024). CAARS-S:S scores decreased significantly vs. placebo in both OROS MPH arms (P < 0.05). There was no significant change in SDS score from baseline in either treatment arm, although significant benefit vs. placebo was observed on several AIM-A subscales. Treatment was well tolerated.

CONCLUSIONS

OROS MPH provided overall benefits in the treatment of adults with ADHD.

A randomized, placebo- and active-controlled study of paliperidone extended-release as maintenance treatment in patients with bipolar I disorder after an acute manic or mixed episode

BACKGROUND

Paliperidone ER monotherapy was efficacious in treating acute mania in two 3-week studies in patients with bipolar I disorder. We assessed its efficacy in a study investigating maintenance treatment of clinically stable patients with this disorder.

METHODS

Patients (n=766), aged 18 to 65 years inclusive, with current manic or mixed episodes were initially randomized (4:1) to flexibly-dosed paliperidone ER (3-12 mg/day) or olanzapine (5-20 mg/day; 3-week acute treatment phase); responders continued the same treatment (12-week continuation phase). Patients on paliperidone ER who achieved remission during this phase were randomized (1:1) to fixed-dose paliperidone ER (n=152) or placebo (n=148); those on olanzapine continued to receive that at fixed dose (n=83) (maintenance phase).

RESULTS

Median time to recurrence of any mood symptoms (primary endpoint) was: 558 days (paliperidone ER), 283 days (placebo) and not observed with olanzapine (<50% of patients experienced recurrence). Time to recurrence of any mood symptoms was significantly longer with paliperidone ER than placebo (p=0.017; based on weighted Z-test at 0.0198 significance level; hazard ratio [placebo: paliperidone ER; unweighted 95% confidence interval]: 1.43 [1.03; 1.98]); the difference was significant for preventing recurrence of manic, but not depressive, symptoms. Treatment-emergent adverse events (maintenance phase) occurred more often in olanzapine group (64%) than placebo (59%) or paliperidone ER groups (55%).

LIMITATIONS

Responder-enriched design prevents extrapolation of data to patients not previously stabilized on paliperidone ER.

CONCLUSIONS

Paliperidone ER significantly delayed the time to recurrence of any mood symptoms, versus placebo, in patients with bipolar I disorder. No new safety concerns emerged.

Evaluation of the efficacy and safety of paliperidone extended-release in the treatment of acute mania: a randomized, double-blind, dose-response study

BACKGROUND

Atypical antipsychotics are effective in the treatment of bipolar I disorder. In this 3-week double-blind study, the efficacy and safety of paliperidone extended-release (ER) tablets were assessed in patients with acute mania.

METHODS

Patients experiencing a manic or mixed episode (Young Mania Rating Scale [YMRS] total score ≥20), were randomly assigned to 1 of 3 fixed doses of once-daily paliperidone ER (3, 6, or 12-mg), or placebo (1:1:1:1 ratio).

RESULTS

In total, 469 patients were randomly assigned to treatment with paliperidone ER 3mg (n=112), 6 mg (n=120), or 12 mg (n=115); or placebo (n=122). Mean (SD) change in YMRS total score from baseline to the 3-week endpoint (primary variable) was statistically significantly different for the paliperidone ER 12 mg group (-13.5 [9.17], p=0.025), but not the 6 mg (-11.4 [9.98], p=0.57) or 3mg (-9.1 [11.18], p=0.79) groups compared with placebo (-10.1 [10.21]). Headache was the most common treatment-emergent adverse event (17% total paliperidone ER versus 12% placebo).

LIMITATIONS

A statistically significant (p=0.0032) treatment-by-country interaction occurred, which confounded interpretation of study results. Paliperidone ER and placebo did not differ statistically for the primary efficacy variable among patients from the United States sites (74% of the intent-to-treat analysis set).

CONCLUSIONS

Paliperidone ER 12 mg/day was superior to placebo in the treatment of acute mania. Change from baseline in YMRS total score increased with the dose of paliperidone ER. Paliperidone ER was generally tolerated by patients with bipolar I disorder and no new safety signal was detected.

Paliperidone extended-release as adjunctive therapy to lithium or valproate in the treatment of acute mania: a randomized, placebo-controlled study

BACKGROUND

Combination treatment with atypical antipsychotics and a mood stabilizer is often recommended for treatment of manic or mixed episodes associated with bipolar I disorder.

METHODS

Eligible patients (n=300) with a Young Mania Rating Scale (YMRS) total score ≥20 were randomly allocated (1:1) to continue mood stabilizer monotherapy or receive flexibly-dosed paliperidone ER (3-12 mg/day) in addition (combination treatment) for 6 weeks. The primary efficacy variable was the change from baseline to endpoint in the YMRS total score.

RESULTS

The mean (SD) YMRS total score at baseline was 26.7 (5.26); 33% of patients presented with a mixed (as distinct from a manic) episode and 62% were on valproate and 38% on lithium. The mean (SD) change from baseline to endpoint in the YMRS total score was not significantly different for combination treatment (-14.3 [10.0]) compared with mood stabilizer monotherapy (-13.2 [10.9]; p=0.16). Combination treatment also failed to separate from mood stabilizer monotherapy for the secondary efficacy measures. The incidence of treatment-emergent adverse events was higher with combination treatment (70%) than with mood stabilizer monotherapy (54%); insomnia was the most common adverse event in both treatment groups (11%).

LIMITATIONS

The relatively low doses of paliperidone ER used in this study and the conduct across different countries may have contributed to its failure to differentiate combination treatment from mood stabilizer monotherapy for the primary and secondary efficacy measures.

CONCLUSIONS

In this study, flexibly-dosed paliperidone ER used as adjunctive therapy to mood stabilizers did not demonstrate efficacy over mood stabilizer monotherapy. No new safety signals were observed with combination treatment in this population.

Number needed to treat and number needed to harm with paliperidone palmitate relative to long-acting haloperidol, bromperidol, and fluphenazine decanoate for treatment of patients with schizophrenia

BACKGROUND

We analyzed data retrieved through a PubMed search of randomized, placebo-controlled trials of first-generation antipsychotic long-acting injectables (haloperidol decanoate, bromperidol decanoate, and fluphenazine decanoate), and a company database of paliperidone palmitate, to compare the benefit-risk ratio in patients with schizophrenia.

METHODS

From the eight studies that met our selection criteria, two efficacy and six safety parameters were selected for calculation of number needed to treat (NNT), number needed to harm (NNH), and the likelihood of being helped or harmed (LHH) using comparisons of active drug relative to placebo. NNTs for prevention of relapse ranged from 2 to 5 for paliperidone palmitate, haloperidol decanoate, and fluphenazine decanoate, indicating a moderate to large effect size.

RESULTS

Among the selected maintenance studies, NNH varied considerably, but indicated a lower likelihood of encountering extrapyramidal side effects, such as akathisia, tremor, and tardive dyskinesia, with paliperidone palmitate versus placebo than with first-generation antipsychotic depot agents versus placebo. This was further supported by an overall higher NNH for paliperidone palmitate versus placebo with respect to anticholinergic use and Abnormal Involuntary Movement Scale positive score. LHH for preventing relapse versus use of anticholinergics was 15 for paliperidone palmitate and 3 for fluphenazine decanoate, favoring paliperidone palmitate.

CONCLUSION

Overall, paliperidone palmitate had a similar NNT and a more favorable NNH compared with the first-generation long-acting injectables assessed.

A comparison of serum prolactin concentrations after administration of paliperidone extended-release and risperidone tablets in patients with schizophrenia

Increases in serum prolactin concentrations after administration of risperidone have been attributed, by some, to the availability of paliperidone in plasma. This double-blind, randomized, parallel-group study in patients with schizophrenia compared serum prolactin concentrations following the administration of paliperidone extended-release and risperidone immediate-release tablets. At steady state, the doses administered resulted in a similar exposure to paliperidone and the pharmacologically active fraction of risperidone (i.e. risperidone + paliperidone), respectively. Eligible patients were randomized to either paliperidone extended-release 12 mg on days 1-6 or risperidone immediate-release 2 mg on day 1 and 4 mg on days 2-6. Mean serum prolactin concentrations increased on day 1 (C(max): 71.8 ng/ml and 89.7 ng/ml reached at 6.5 hours and 2.6 hours for paliperidone extended-release and risperidone immediate-release, respectively). On day 6, serum prolactin concentration-time profiles were similar for both treatments, with overall higher serum prolactin concentrations than on day 1 (AUC(0-24 h): 1389 and 842 ng h/ml, and 1306 and 741 ng.h/ml on day 6 and day 1 for paliperidone extended-release and risperidone immediate-release, respectively). These results indicate that paliperidone extended-release 12 mg and risperidone immediate-release 4 mg, administered over a period of 6 days, lead to similar elevations in serum prolactin concentrations.

A randomized, placebo- and active-controlled study of paliperidone extended release for the treatment of acute manic and mixed episodes of bipolar I disorder

OBJECTIVES

To evaluate the antimanic efficacy and safety of paliperidone extended-release (ER) tablets in patients with bipolar I disorder.

METHODS

This study included a 3-week, double-blind, acute treatment phase (paliperidone ER versus placebo, with quetiapine as control), and a 9-week, double-blind, maintenance phase (paliperidone ER versus quetiapine). Patients [n = 493; Young Mania Rating Scale (YMRS) score >or= 20] were randomized (2:2:1) to flexibly dosed paliperidone ER (3-12 mg/day), quetiapine (400-800 mg/day), or placebo for the acute treatment phase. During the maintenance phase, patients assigned to placebo were switched to paliperidone ER but not included in analysis of efficacy.

RESULTS

Paliperidone ER was superior to placebo at the 3-week endpoint {primary outcome; least-squares mean difference in change from baseline in YMRS scores [95% confidence interval (CI)]: -5.5 (-7.57; -3.35); p < 0.001} and noninferior to quetiapine at the 12-week endpoint [least-squares mean difference (95% CI): 1.7 (-0.47; 3.96)]. The median mode dose during the 12-week treatment period was 9 mg for paliperidone ER and 600 mg for quetiapine. The most common (>or= 10%) treatment-emergent adverse events during the 12-week period were: headache (16%), somnolence (10%), and akathisia (10%) for paliperidone ER; somnolence (21%), sedation and dry mouth (17% each), headache (14%), and dizziness (13%) for quetiapine. Body weight increase >or= 7% from baseline to 12-week endpoint was 8% with paliperidone ER and 17% with quetiapine. A higher percentage of paliperidone ER (13.9%) versus quetiapine patients (7.5%) 'switched to depression' at the12-week endpoint.

CONCLUSIONS

Paliperidone ER (3-12 mg/day) was efficacious and tolerable in the treatment of acute mania.

The effects of paroxetine on the pharmacokinetics of paliperidone extended-release tablets

INTRODUCTION

Co-morbid medical and psychiatric conditions are common in individuals with schizophrenia. As such, selecting antipsychotic medications with a low potential for drug-drug interactions (DDIs) is crucial, as many are extensively metabolized by hepatic cytochrome P450 (CYP) isozymes.

METHODS

This randomized, crossover study examined the effects of paroxetine (a potent CYP2D6 inhibitor) on the pharmacokinetic parameters of a single dose of the novel antipsychotic agent, paliperidone extended-release tablets (paliperidone ER), in healthy subjects.

RESULTS

The mean C (max) and AUC of paliperidone were slightly higher and paliperidone clearance was slightly lower following co-administration of paliperidone ER with paroxetine. There was a ratio of geometric treatment means of 116.48% for AUC (infinity) [90% CI: 104.49-129.84]. However, the increase in total exposure to paliperidone was not considered clinically relevant. The incidence of adverse events was lower when subjects received the combination of paliperidone ER and paroxetine compared with paroxetine alone.

DISCUSSION

Results suggest that no clinically relevant pharmacokinetic interaction occurs when paroxetine and paliperidone ER are co-administered and, therefore, initiation or discontinuation of concomitant treatment with CYP2D6-inhibiting drugs does not appear to warrant an adjustment in paliperidone ER dosage.

Prediction of functional outcome and in-hospital mortality after admission with oral anticoagulant-related intracerebral hemorrhage

BACKGROUND AND PURPOSE

Early survival of patients with intracerebral hemorrhage in general is known to be most strongly dependent on the Glasgow Coma Scale score on admission. The aim of this study was to examine the factors determining functional outcome and in-hospital mortality of patients admitted with an intracerebral hemorrhage related to oral anticoagulant (OAC) use.

METHODS

Correlation studies and multiple logistic regression analyses were performed on data from a retrospective series of 42 patients admitted with OAC-related intracerebral hemorrhages over a 6-year period to a tertiary care center in the north of Scotland.

RESULTS

The functional outcome after an OAC-related intracerebral hemorrhage was dependent on maximum diameter of hematoma on CT scan (R:=-0.72, P:<0. 001) and international normalized ratio (INR) (R:=-0.35, P:=0.024). Hematoma diameter and INR were not themselves strongly correlated (R:=0.31, P:=0.099). In-hospital mortality can be predicted by the Glasgow Coma Scale score alone (R:(2)=0.36, overall predictive accuracy 68%) but more accurately by a logistic regression model including hematoma diameter and CT signs of cerebrovascular disease (R:(2)=0.70, predictive accuracy 83%).

CONCLUSIONS

Neither functional outcome nor in-hospital mortality appears to be strongly dependent on INR measured on admission. CT scan, however, provides essential information and allows accurate predictions about the short-term outcome of OAC-related intracerebral hemorrhages.

Analysis of risk factors involved in oral-anticoagulant-related intracranial haemorrhages

We examined risk factors for intracranial bleeding while on oral anticoagulants (OACs) in 68 patients admitted to hospital over a 6-year period, and 204 out-patient controls followed-up in an OAC clinic. Under multivariate analysis, significant risk factors for OAC-related intracranial bleeds were hypertension (OR (95%CI) 2.69 (1.04-6.97), duration of OAC therapy < or =12 months (OR 3.74 (1.21-11.56)), duration > or =96 months (OR 0.25 (0.07-0.88)), and International Normalized Ratio on admission >4.5 (OR 10.92 (2.46-48.43)). A logistic regression model including the above variables along with a history of 'cerebrovascular disease' (OR 2.32 (0.98-5.46)) correctly predicted intracranial bleeding (or its absence) during OAC therapy in 85% of all patients. The risk associated with advanced age and concomitant aspirin use was not significantly increased in this analysis. It is important to achieve tight control of INR, particularly in the early months of treatment. Patients with previous cerebrovascular disease are at increased risk of intracranial bleeding on warfarin, and hypertensive patients should have especially close monitoring and optimal control of their blood pressure.

Course, management and outcome of oral-anticoagulant-related intracranial haemorrhages

The aim of this study was to compare the clinical course and radiological features of oral anticoagulant (OAC)-related intracranial haemorrhages with those of haemorrhages unrelated to OAC use admitted over the last six years to a tertiary care centre in the North of Scotland. We furthermore wished to determine the measures taken for reversal of OAC therapy and the resulting short-term outcome. Sixty-eight patients had been treated with OACs at the time of intracranial haemorrhage (32% subdural, 62% intracerebral). Patients admitted with OAC-related and unrelated haemorrhages did not differ significantly in any of the clinical features considered. On CT scan, there was no significant difference according to OAC use in the mean size of subdural (depth 15 +/- 5 vs. 18 +/- 8 mm, p = 0.36), or intracerebral haematomas (max. diameter 40 +/- 21 vs. 41 +/- 20 mm, p = 0.73). No reversal measures were taken in 38% of OAC-treated patients. In-hospital mortality was significantly higher for OAC-related haemorrhages compared to unrelated haemorrhages (38% vs. 18%, p = 0.001). To further elucidate the effects of anticoagulant reversal on the outcome of OAC-related intracranial haemorrhages, a large-scale prospective study is warranted.

Intracerebral haemorrhages and oral anticoagulation in the north of Scotland

The aim of this study has been twofold: 1--to examine the impact of oral anticoagulant (OAC) use on a possible recent rise in the admission rate of intracerebral haemorrhages to Aberdeen Royal Infirmary (ARI), and 2--to estimate the absolute risk of intracranial haemorrhage for outpatients followed up in the OAC Clinic at ARI. The number of patients admitted to ARI with intracerebral bleedings increased by 60% between 1993 and 1998. A corresponding increase in the proportion of patients with concurrent OAC use (4.7% vs 15.7%, p = 0.055) cannot sufficiently explain the increase in the total number of intracerebral haemorrhages. The average annual incidence of intracranial haemorrhages for the OAC Clinic at ARI is found to be acceptably low at 0.33% per year. Further audit of the large number of patients receiving warfarin outwith the supervision of the clinic is urgently required.

Characterization of pituitary function with emphasis on GH secretion in the chronic fatigue syndrome

OBJECTIVE

Previous studies have revealed that hormonal disturbances may accompany the chronic fatigue syndrome (CFS). Changes in the secretion of the pituitary-adrenal axis have been demonstrated, as well as abnormalities in the GH-IGF-I axis. However, data have not always been well characterized and were sometimes conflicting. The small number of CFS patients investigated in earlier studies may have played a role in the interpretation of the results.

SUBJECTS AND DESIGN

Hormonal testing was performed in 73 nonobese CFS patients and nonobese 21 age-and gender-matched healthy controls. We investigated GH, ACTH and cortisol responses to insulin-induced hypoglycaemia. In a subgroup of patients arginine and clonidine stimulation for GH was also performed. Nocturnal secretion of GH, ACTH and cortisol were determined. Serum levels of IGF-I, prolactin, TSH, and free thyroxine were also measured. Visceral fat mass was assessed by CT scanning.

RESULTS

GH response to insulin induced hypoglycaemia assessed by peak value (17.0 +/- 13.1 microg/l vs. 22. 1 +/- 9.8 microg/l; P = 0.01) and by AUC (450.0 +/- 361.3 microg/l vs. 672.3 +/- 393.0 microg/l; P = 0.002) was significantly decreased in CFS patients vs. controls. Nocturnal GH secretion assessed by GH peak value (5.4 +/- 3.7 vs. 9.0 +/- 5.1 microg/l; P = 0.44) and by AUC (34.4 +/- 20.2 vs. 67.4 +/- 43.1; P = 0.045) was also significantly impaired in CFS patients. Arginine and clonidine administration showed no differences in GH secretion between CFS patients and controls. In the CFS group, GH peak values were significantly higher after ITT than after arginine (P = 0.017) or clonidine (P = 0.001). No differences in serum IGF-I levels were found between CFS patients and controls. Except for a significantly lower nocturnal cortisol peak value, no differences were found in ACTH and cortisol secretion between CFS patients and controls. Significantly higher serum prolactin levels (7.4 +/- 4.7 microg/l vs. 4.4 +/- 1.3 microg/l; P = 0.004) and significantly higher serum TSH levels (1.6 +/- 1.0 mU/l vs. 1.0 +/- 0.4 mU/l; P = 0.011) were found in CFS patients. Serum free thyroxine was comparable in both groups. Visceral fat mass was significantly higher in CFS patients (86.6 +/- 34.9 cm2 vs. 51.5 +/- 15.7 cm2; P < 0.001).

CONCLUSIONS

We observed a significant impairment of GH response during insulin-induced hypoglycaemia and a low nocturnal GH secretion in CFS patients. These changes did, however, not lead to different concentrations in serum IGF-I. The clinical expression of this inadequate GH secretion can thus be questioned, although the alteration in body composition may be related to this relative GH deficiency. Significantly increased prolactin and TSH levels were found when compared to controls. These findings give support to the hypothesis of a decreased dopaminergic tone in CFS. Further investigations are required in order to identify specific adaptations within the neurotransmitter system in CFS and to determine the clinical importance of the impaired GH homeostasis.

A giant prolactinoma presenting with unilateral exophthalmos: effect of cabergoline and review of the literature

We report the case of a 45-year-old male presenting with unilateral exophthalmos due to a large tumoral mass invading the skull base. Ophthalmologic examination did not show any visual field defects. Imaging techniques demonstrated extension of a huge tumor (approx. 8x8x8 cm) into the right orbit and nasopharynx. Endocrine work-up revealed grossly elevated serum prolactin (PRL) levels (26,466 microg/l, nl. < 12), pointing to a large, invasive macroprolactinoma. Stimulation tests indicated associated partial adrenal and growth hormone deficiencies. Planned surgery was abandoned, and the patient was instead treated with the long-acting dopamine agonist, cabergoline. Over a period of one year, serum PRL dropped to 131 microg/l, while the tumor mass shrank to less than 50% of its original volume (with 3.5 mg/week of cabergoline). The exophthalmos disappeared, and the patient did not develop rhinorrhea or any other side effects from treatment with cabergoline. The efficacy was maintained throughout the second year (ultimate serum PRL 74 microg/l, and final size less than 10% of the original). With reference to this case, we review other macroprolactinomas reported in the recent literature for associated exophthalmos, grossly elevated serum PRL levels (> or = 15,000 microg/l), and/or "giant" size (> or = 4 cm in maximum diameter). We highlight the use of dopamine agonists in the treatment of prolactinomas with such unusual characteristics.

Cushing's syndrome in pregnancy treated by ketoconazole: case report and review of the literature

We report on a 30-year-old female with a pituitary-dependent Cushing's disease, who refused transsphenoidal surgery and was treated with ketoconazole and cabergoline. After approximately 3 years of therapy, the patient herself decided, without the knowledge of her treating physician, to interrupt contraception. As the patient became pregnant she ceased the intake of all medication (between the third and seventh week), but resumed it soon after pregnancy was diagnosed because of relapsing clinical signs. Pregnancy and vaginal delivery at 37 weeks gestation passed uneventfully. The newborn male infant did not demonstrate any congenital malformations and was normally sexually developed. With reference to this case, we discuss the difficulties in the medical treatment of Cushing's syndrome during pregnancy. Whereas outside pregnancy only efficacy and side-effects are taken into account, teratogenicity is an important question in these patients. Experience with different drugs is listed. This is only the second time that ketoconazole has been used during pregnancy for the treatment of Cushing's syndrome. We argue that ketoconazole may be safe as well as effective in pregnancy and, furthermore, without any consequences for the child.

Secretion of growth hormone in patients with chronic fatigue syndrome

Decreased serum levels of insulin-like growth factor I (IGF-I) are common in patients with fibromyalgia, which is frequently associated with chronic fatigue syndrome (CFS). Twenty patients with CFS (7 men, 13 women; age range, 30-60 years) and age- and sex-matched controls were tested for peak GH responses to insulin-induced hypoglycaemia and arginine administration. Nocturnal secretion of GH and serum levels of IGF-I were also measured. Serum IGF-I SDS (+/- SD) was significantly lower in patients with CFS than in controls (SDS, -0.39 +/- 1.07 vs 0.33 +/- 0.84; P = 0.02). Patients with CFS also tended to have reduced nocturnal secretion of GH (area under the curve, 32.4 +/- 18.3 vs 62.7 +/- 43.7 microg/l/15 minutes; P= 0.06), but peak GH responses to insulin-induced hypoglycaemia and arginine administration did not differ significantly between the two groups. It is not clear whether the tendency for impaired spontaneous nocturnal GH secretion in patients with CFS is a cause or an effect of the condition.

Role of hepatic arterial embolisation in the treatment for metastatic insulinoma. Report of two cases and review of the literature

Malignant insulinomas are very rare. They have typical clinical and biochemical characteristics that allow an early detection and distinction from other sorts of islet cell carcinoma. As a result a curative resection can occasionally be managed. Nevertheless, for more advanced stages the same treatment options as for other metastatic neuroendocrine tumours must be considered: palliative surgery, medical treatment, chemotherapy and hepatic arterial (chemo-) embolisation. Especially the last kind of treatment has recently gained interest. We report two cases of metastatic insulinoma treated in this way. In the first case we are able to record an unusually long survival through the single use of sequential embolisation, following palliative resection of the primary tumour. In the second case we describe the current way to use this technique, i.e. in combination with chemotherapy. We argue that it might be more important in the treatment of metastatic insulinoma to combine hepatic arterial embolisation with other types of local or systemic therapy, rather than the choice of this most efficient technique on its own.

Obstructive hydrocephalus as complication of a giant nonfunctioning pituitary adenoma: therapeutical approach

We report the case of a 61-year-old male presenting with a giant nonfunctioning pituitary tumour extending into the third ventricle and thereby causing obstructive hydrocephalus. The main complaints consisted of disturbed vision and somnolence. The patient was initially treated by ventriculoperitoneal shunting, with immediate improvement of his mental status. Transcranial resection of the tumour was performed shortly thereafter, but only a limited part of the tumour could safely be removed. By immunohistochemistry the diagnosis of gonadotroph adenoma was made. After the operation, the patient's vision deteriorated temporarily. Because of the risk of further damage to the optic nerve, radiation therapy was postponed. Instead, treatment with the long-acting dopamine agonist cabergoline was instituted, which resulted in a gradual improvement of vision. Two years later a transsphenoidal operation was performed because of acute worsening of the visual fields due to central tumour necrosis with slight volume expansion. Vision improved considerably after surgery. Radiotherapy is scheduled in the near future. This case is an illustration of the complications of giant nonfunctioning pituitary adenomas. The therapeutical approach to obstructive hydrocephalus in these instances is reviewed.

Serum creatine, creatinine, and other guanidino compounds in patients with thyroid dysfunction

Serum levels of creatine (CT), creatinine (CTN), urea, guanidinosuccinic acid (GSA), guanidinoacetic acid (GAA), guanidine (G), arginine (Arg), homoarginine (Harg), argininic acid (ArgA), and alpha-keto-delta-guanidinovaleric acid (alpha-K-delta-GVA) were measured in 54 patients with hyperthyroidism, 56 with subclinical hyperthyroidism, 28 with subclinical hypothyroidism, and 51 with hypothyroidism compared with 62 euthyroid controls. In agreement with previous reports, serum CT increased (+35%) and CTN decreased (-17.6%) in hyperthyroidism as compared with normal thyroid function, whereas the opposite was seen in hypothyroidism (-17.7% and +11%, P < .0001). Original findings from this study are a highly significant decrease in GSA (-41.7%) and GAA (-36.8%) in hyperthyroidism and an increase in GSA (+36%) in hypothyroidism (P < .0001). In addition, a slight decrease in hyperthyroidism and hypothyroidism was noted for Arg (-6.2% and -13.2%, P = .001) and Harg (-14.8% and -18.1%, P = .05). By contrast, no significant change was seen in levels of urea, G, ArgA, and alpha-K-delta-GVA. No major differences were found for any of the compounds between subclinical hypothyroidism, euthyroidism, and subclinical hyperthyroidism. There was a highly significant positive linear correlation between urea and GSA levels in hyperthyroidism, euthyroidism, and hypothyroidism (r = .68, r = .77, and r = .75, P < .0001), taking into account that for the same increase in urea, GSA increased threefold more in hypothyroid versus hyperthyroid patients. In conclusion, apart from CT and CTN, significant changes can be found in serum levels of GSA, GAA, Arg, and Harg in patients with thyroid dysfunction. Subclinical thyroid dysfunction does not seem to induce changes in serum levels of guanidino compounds. Decreased serum GSA and GAA levels might be an additional indicator of hyperthyroidism.

Thyrotoxic periodic paralysis, an unusual cause of hypokalemic periodic paralysis

Over a two-year period two patients were admitted to the hospital with episodes of paralysis and hypokalemia. In the first patient, familial hypokalemic periodic paralysis was initially suspected. Only several months later was Graves' disease diagnosed and this diagnosis linked to thyrotoxic periodic paralysis. The second patient came to notice after treatment with thyreostatic drugs was stopped prematurely and paralysis together with hypokalemia developed. Thyrotoxic periodic paralysis, being rare outside Asia, closely mimics the clinical presentation of familial hypokalemic periodic paralysis. Mainly men in the third decade with a negative family history are affected. Graves' disease is the most common cause of hyperthyroidism. This disorder is not always clinically apparent since signs of hyperthyroidism may be easily missed. Therefore thyroid function tests are part of the diagnostic workup of hypokalemic periodic paralysis. Correction of thyroid function is essential to treatment. The pathophysiology is still controversial.