Relative Bioavailability of Methylphenidate Extended-release Chewable Tablets Chewed Versus Swallowed Whole

PURPOSE

Methylphenidate hydrochloride extended-release chewable tablet (MPH ERCT) is approved for treatment of attention deficit hyperactivity disorder in patients aged 6 years and older. This article evaluates the pharmacokinetic parameters and relative bioavailability of MPH ERCT when chewed versus swallowed whole.

METHODS

In this open-label, single-dose, 3-period, 3-treatment crossover study, 12 healthy adult volunteers were randomly assigned to treatment sequence. In each period, subjects received a single 40-mg dose of the assigned treatment (MPH ERCT chewed, MPH ERCT swallowed whole, or methylphenidate extended-release oral suspension [MEROS]). Blood samples for pharmacokinetic analysis were collected for 24 hours postdose. Key pharmacokinetic parameters included C_max, AUC_0-t, and AUC_0-∞.

FINDINGS

The geometric mean values for AUC_0-t, AUC_0-∞, and C_max were similar for MPH ERCT chewed, MPH ERCT swallowed whole, and MEROS. In all pairwise between-treatment comparisons, the 90% CIs of the geometric mean ratios for AUC_0-t, AUC_0-∞, and C_max were fully contained within the bioequivalence range of 80% to 125%. Early exposure over the first 4 hours after dosing (AUC_0-4) was similar for MPH ERCT chewed versus swallowed whole; AUC_0-4 was approximately 15% lower for MPH ERCT, either chewed or swallowed, compared with MEROS. Each treatment was generally well tolerated.

IMPLICATIONS

There was no difference in overall rate or extent of exposure of methylphenidate when MPH ERCT was chewed versus swallowed whole by healthy volunteers.

Effect of Food Intake on the Pharmacokinetics of a Novel Methylphenidate Extended-Release Oral Suspension for Attention Deficit Hyperactivity Disorder

We conducted an open-label, single-dose, randomized, crossover study in healthy adults to assess the impact of food on the bioavailability of 60 mg methylphenidate extended-release oral suspension (MEROS; Quillivant XR™)-a long-acting stimulant for the treatment of attention deficit hyperactivity disorder-by comparing the pharmacokinetic parameters under fed and fasting conditions. When MEROS 60 mg was administered under fed conditions compared with fasting conditions, the exposure of methylphenidate (d enantiomer) was higher, with a mean area under the plasma concentration-vs-time curve (AUC)_0-t of 160.2 ng·h/mL vs 140.4 ng·h/mL, and a mean AUC_0-inf of 163.2 ng·h/mL vs 143.7 ng·h/mL, respectively. The ratios of the ln-transformed geometric means for methylphenidate for AUC_0-t and AUC_0-inf were 119.5% (90%CI, 115.7% to 123.5%) and 119.0% (90%CI, 115.2% to 122.8%), respectively, within the standard 80% to 125% bioequivalence acceptance range indicating no food effect on the overall exposure (rate and extent). There was a small increase in the peak plasma concentration (127.6% [90%CI, 119.9% to 135.8%]). However, this effect was small and not likely to be clinically significant. Overall, MEROS 60 mg was safe in both the fed and fasting condition when administered to healthy volunteers in this study.

Effects of clonidine and methylphenidate on family quality of life in attention-deficit/hyperactivity disorder

OBJECTIVE

The aim of this study was to determine the effect on family quality of life (QOL) of clonidine (CLON) and methylphenidate (MPH), used alone and in combination, in treating attention-deficit/hyperactivity disorder (ADHD).

METHODS

Two proxy QOL measures were used in a multicenter, double-blind, placebo-controlled 16-week trial of 122 children, ages 7-12 years, with ADHD. Children were randomized to one of four groups in which they received MPH, CLON, a combination of drugs, or placebo. QOL was measured with the Daily Hassles Scale and the Impact on Family Scale at baseline and at 16 weeks.

RESULTS

In a general linear model repeated measures analysis, treatment groups improved over a 16-week period compared to placebo for Daily Hassles and Impact on Family, as well as in symptoms measured by the ADHD Rating Scale. QOL measures correlated moderately with efficacy and symptom measures.

CONCLUSION

This study provides evidence that measures of QOL for the family are sensitive to pharmacological treatment of ADHD. The correlation pattern of the QOL measures with symptom and efficacy variables supported family QOL as a related but separate construct. Clonidine for Attention-Deficit/Hyperactivity Disorder Treatment Study (CAT) Trial Registry Name: Clinicaltrials.gov; ID Number, NCT00031395; URL, http://clinicaltrials.gov/ct/show/NCT00031395?order=8/ .

Effects of phytoestrogenic isoflavones from red clover (Trifolium pratense L.) on experimental osteoporosis

The most common type of osteoporosis is bone loss associated with ovarian hormone deficiency at menopause. There is evidence that diets which contain high levels of phytoestrogenic isoflavones are associated with a low incidence of osteoporosis and menopausal symptoms. Plant extracts, which contain high levels of isoflavones, such as Red clover (Trifolium pratense L.), have been used to reduce menopausal symptoms. The objective of this study was to evaluate the preventive effects of Red clover total isoflavones on the progression of bone loss induced by estrogens deficiency (ovariectomy) in rats. Bilateral ovariectomy was performed on female Wistar rats. One week after the operation the rats were treated with an oral dose of 20 and 40 mg of total isoflavones daily for 14 weeks. The results from this study showed that the ovariectomy reduced bone mineral content, femoral weight, femoral density, mechanical strength of the tibia and increased the levels of bone specific alkaline phosphatase in the serum and the number of osteoclasts in the femur sections compared with sham operated controls. Treatment with isoflavones significantly increased bone mineral content, mechanical strength of the tibia, femoral weight, femoral density and prevented the rise of serum alkaline phosphatase levels. In addition, the treatment with isoflavones significantly reduced the number of osteoclasts compared with the ovariectomized control rats. These findings suggest that Red clover isoflavones are effective in reducing bone loss induced by ovariectomy, probably by reducing of the bone turnover via inhibition of bone resorption.

Longitudinal, 15-year follow-up of children born at less than 29 weeks' gestation after introduction of surfactant therapy into a region: neurologic, cognitive, and educational outcomes

OBJECTIVE

To measure the primary and secondary school-age neurologic, cognitive, and educational outcomes in a cohort of extremely premature infants born after the introduction of exogenous surfactant therapy in a circumscribed region.

METHODS

Two hundred thirteen infants born at <29 weeks' gestation were cared for at a regional referral center during 1985-1987. At primary school age, neurologic and cognitive outcomes, educational achievement, school placement, health status, and socioeconomic status were determined by follow-up visit. At secondary school age, school placement and health status were evaluated by telephone interview.

RESULTS

One hundred thirty-two infants survived to school age, of whom 127 (96%) were evaluated in 1992-1995 and 126 (95%) were evaluated in 2000. Mean ages were 7.0 years at first follow-up and 14.1 years at second follow-up. At primary-school age follow-up, 19 children (15%) had cerebral palsy, 24 (19%) had a general cognitive index <70, and 41 (32%) were placed in a self-contained, special classroom. Thirty-nine children (31%) had no physical or educational impairment, whereas 27 (21%) had at least 1 severe disability. At secondary school age, cerebral palsy incidence remained unchanged, whereas 36 children (29%) were placed in a special classroom. Fifty-one children (41%) had no physical or educational impairment, whereas 24 (19%) had at least 1 severe disability. Neonatal intraventricular hemorrhage and low socioeconomic status were the strongest predictors of adverse outcomes.

CONCLUSIONS

Premature infants born in the surfactant era remain at high risk of neurodevelopmental compromise. Although many of these children do well, a significant minority will require intensive special educational services through secondary school age.

Association between prenatal exposure to methylmercury and cognitive functioning in Seychellois children: a reanalysis of the McCarthy Scales of Children's Ability from the main cohort study

Methylmercury (MeHg) is a neurotoxicant whose high-dose effects first became known following a number of poisoning outbreaks that occurred worldwide. The primary human exposure is low dosage from fish consumption. Studies of fish-eating populations have not found a consistent pattern of association between exposures and outcomes. Therefore, examining specific areas of cognitive functioning has been suggested as an important approach to determine whether more subtle effects of MeHg exposure are present. In the Seychelles longitudinal study of prenatal and postnatal MeHg exposure from fish consumption and development, the McCarthy Scales of Children's Abilities (MSCA) were administered to children at age 66 months. No association between MeHg exposure and performance on the MSCA General Cognitive Index was identified. We analyzed these data further to determine whether associations were present on specific subscales of the MSCA. The standard MSCA subscales were analyzed. Then, more specific subscales of the MSCA were defined and analyzed utilizing a neuropsychological approach. The subscales were recombined to approximate the domains of cognitive functioning evaluated in the Faroes and New Zealand studies. Analyses of both the standard and the recombined MSCA subscales showed no adverse associations with MeHg exposure and neuropsychological endpoints. A positive association between postnatal MeHg exposure and performance on the MSCA Memory subscale was found. These findings are consistent with previous reports from the Seychelles study in that no adverse effects of MeHg exposure from fish consumption can be detected in this cohort.

Rey-Osterrieth Complex Figure Test performance in acute, chronic, and remitted schizophrenia patients

To assess visual memory disturbance in different forms of schizophrenia, we compared Rey-Osterrieth Complex Figure Test (RCF) performance in acutely psychotic, chronically psychotic, and outpatient schizophrenia patients and in a control group of acutely psychotic patients with disorders other than schizophrenia. There were no group differences on the copy condition of the RCF. The chronic schizophrenia group utilized more abnormal copying strategies, however, than the outpatient or nonschizophrenia groups. Moreover, the chronic schizophrenia group demonstrated significantly poorer recall than the outpatient or nonschizophrenia groups, and a trend toward poorer performance than the acute schizophrenia group. Both groups of inpatient schizophrenia patients were characterized by a lack of relationship between copying strategies and recall accuracy. These data suggest that (a) chronic schizophrenia patients are characterized by more severe memory impairment than are nonchronic schizophrenia patients, and (b) visual memory disturbance in chronic schizophrenia is not solely a function of encoding difficulties.

School-age follow-up of prophylactic versus rescue surfactant trial: pulmonary, neurodevelopmental, and educational outcomes

BACKGROUND

Exogenous surfactant replacement has improved survival and reduced pulmonary complications of prematurity. Improved early outcomes for infants of <30 weeks' gestation treated with a strategy of prophylactic versus rescue surfactant, if needed, were demonstrated in a multicenter, randomized trial conducted between 1985 and 1988. We reevaluated a subset of survivors from this trial to determine the pulmonary and neurodevelopmental outcomes at school age.

METHODS

At 4.5 to 8 years of age, all survivors from one of the three centers were located, and 96% were evaluated. The original randomization included stratification by center and followed an intention-to-treat methodology in assessing the efficacy of prophylactic versus rescue treatment with surfactant. The follow-up test battery included a health-assessment questionnaire, spirometry, 88% saturation test, neurologic examination, and the McCarthy Scales of Children's Abilities (MSCA) and the Conners' Parent Rating Scale-48. Educational achievement was determined by school class placement and teachers' reports of achievement.

RESULTS

Of the 192 children originally enrolled, 154 survived. Evaluations were performed on 148 of these infants. An abnormal pulmonary history was found in 45 (30%) of the children: 16 (22%) in the prophylactic group and 29 (39%) in the rescue group. Formal pulmonary function was evaluated in 81 children; 29 (78%) in the prophylactic group and 33 (75%) in the rescue group were considered abnormal. No significant differences were found between the two groups on either cognitive or motor subscales of the MSCA, the Conners' Parent Rating Scale-48, the neurologic examination, the education services received in school, or the teacher ratings of below-average academic performance. Intelligence scores measured on the MSCA were low-normal for both groups. Some level of educational assistance was being provided to 72 (49%) of the cohort studied, and both groups had below average educational performance and increased needs for educational assistance.

CONCLUSIONS

Prophylactic surfactant administration to infants of <30 weeks' gestation was associated with fewer long-term clinical pulmonary complications than assignment to rescue administration. Formal pulmonary testing at school age did not reveal significant differences between treatment groups in those infants who could be tested. There also were no group differences found on neurologic, cognitive, behavioral, or educational assessments at school age.

Nonverbal perceptual organization output disability and schizophrenia spectrum symptomatology

Patients with neurodevelopmental syndromes often receive numerous psychiatric diagnoses before the true nature of their disorder becomes apparent. We present a case in which the neuropsychological evaluation played a significant role in reconceptualizing a patient who had received, at various times, diagnoses of schizotypal personality disorder, schizoaffective disorder, and schizophrenia. The identification of specific cognitive deficits in executive functioning, perceptual organization, visual-spatial problem solving, and abstraction led to: 1) a diagnosis of nonverbal perceptual-organization-output disabled; 2) the adoption of a rehabilitative treatment model; and 3) a greater understanding of the way in which the patient's social deficits represented adaptations to her cognitive impairments. Research data and theoretical models relating cognitive deficits to psychiatric symptoms are discussed, and evidence is presented that schizophrenia and certain neurodevelopmental syndromes may share commonalities of pathophysiology. Diagnostic issues arising from similarities between these disorders are discussed. It is suggested that direct comparisons between these groups can aid in clarifying the specific nature of cognitive deficit-symptom relationships, as well as leading to improvements in the understanding, diagnosis and treatment of schizophrenic and neurodevelopmental syndromes.

Pursuit eye movement dysfunction in obsessive-compulsive disorder

Disturbances in neural circuitry including the basal ganglia and prefrontal cortex have been hypothesized to be a cause of obsessive-compulsive disorder (OCD). Because eye movements are often impaired in neurologic diseases affecting these brain areas, oculomotor functioning was assessed in 17 unmedicated patients with OCD and in 25 normal controls. As compared with control subjects, patients with OCD demonstrated low-gain (slow) pursuit eye movements and an increased frequency of square wave jerk intrusions, but no increase in anticipatory saccades. In addition, several OCD patients showed an unusual pattern of intrusive, brief epochs of high-gain (fast) pursuit lasting on the order of 50 to 130 msec. These epochs of fast pursuit moved the eyes ahead of the target being tracked, and were terminated by corrective reversal saccades. Studies of eye movement abnormalities may provide an informative neurophysiologic approach for studying disturbances in basal ganglia and frontal cortical function that have been observed in functional neuroimaging and neuropsychological studies of OCD.