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Biomedical subjects

Steve Mann

Publications and source records attributed to Steve Mann.

5 recordsLinked to original sources
PubMed2007

The use of electronic monitoring (MEMS) to evaluate antipsychotic compliance in outpatients with schizophrenia.

Compliance with antipsychotic treatment is a well-recognized concern in the ongoing management of individuals with schizophrenia. The present investigation incorporated the Medication Event Monitoring System (MEMS) to evaluate compliance in a group of outpatients (N=52) with schizophrenia or schizoaffective disorder. Evaluating compliance as a dichotomous variable and using a threshold of 80%, the rate of noncompliance as measured by MEMS was 52%, considerably higher than self-report (3%), clinician rating (24%) and pill count (25%). The ability of treating clinicians to predict compliance/noncompliance was limited: 13 of 31 (42%) subjects they rated as compliant were noncompliant while 4 of 9 (44%) rated as noncompliant were actually compliant according to MEMS. Factors most consistently associated with noncompliance were higher total symptom scores and dosing complexity i.e., greater than once daily. Based on MEMS data, the overall mean level of compliance was 66%; however, it remains unclear as to what threshold is associated with a compromise in clinical response. More sophisticated measurement tools such as MEMS may assist us in better understanding how level and pattern of antipsychotic noncompliance, factors that at present remain poorly understood, impact on symptom exacerbation.

Adult↗
PubMed2006

Exposure data for personal care products: hairspray, spray perfume, liquid foundation, shampoo, body wash, and solid antiperspirant.

Reliable exposure information for cosmetic and other personal care products and ingredients is needed in order to conduct safety assessments. Essential information includes both the amount of product applied, and the frequency of use. To obtain current data, studies to assess consumer use practices were undertaken. Six widely used personal care product types were included in the studies. Five of the products were cosmetics (spray perfume, hairspray, liquid foundation, shampoo, body wash) and one product was a cosmetic/over-the-counter drug product (solid antiperspirant). Three hundred and sixty women, ages 19-65 years, who regularly use the products of interest, were recruited at 10 different geographical locations within the US. The number of recruits was chosen to ensure a minimum of three hundred completed responses per product type. Subjects were provided with a new container of the brand of product they normally use and kept diaries and recorded detailed daily usage information over a two week period. Products were weighed at the start and completion of the study in order to determine the total amount of product used. Statistical analyses of the data were conducted to derive summary distributions of use patterns. The geometric mean and median usage per application, respectively, for the six product types were: spray perfume, 0.33 g and 0.23 g; hairspray, 2.58 g and 1.83 g (aerosol); 3.64 g and 2.66 g (pump); liquid foundation, 0.54 g and 0.36 g; shampoo, 11.76 g and 9.56 g; body wash, 11.3g and 9.5 g; and solid antiperspirant, 0.61 g and 0.45 g. The mean and median usage per day for the six product types were: spray perfume, 0.53 g and 0.34 g; hairspray, 3.57 g and 2.71 g (aerosol); 5.18 g and 3.74 g (pump); liquid foundation, 0.67 g and 0.45 g; shampoo, 12.80 g and 10.75 g; body wash, 14.5 g and 12.9 g; and solid antiperspirant, 0.79 g and 0.59 g. The mean number of applications per day for spray perfume, hairspray, liquid foundation, shampoo, body wash, and solid antiperspirant was 1.67, 1.49 (aerosol) and 1.51 (pump), 1.24, 1.11, 1.37, and 1.3, respectively. This study provides current exposure information for commonly used products which will be useful for risk assessment purposes.

Administration, Topical↗
PubMed2006

A PET study evaluating dopamine D2 receptor occupancy for long-acting injectable risperidone.

OBJECTIVE: Long-acting injectable risperidone represents the first clinically available depot atypical antipsychotic. The present study used positron emission tomography (PET) to evaluate its dopamine D(2) binding profile at doses of 25, 50, or 75 mg administered every 2 weeks. METHOD: After achieving stabilization with one of the doses, nine patients with a diagnosis of schizophrenia or schizoaffective disorder underwent [(11)C]raclopride PET to measure D(2) occupancy. Participants were scanned twice during the 2-week injection interval: within 3 days after injection (postinjection) and within 5 days before the next injection (preinjection). At the same time, plasma was collected for measurements of risperidone plus 9-hydroxyrisperidone. RESULTS: Mean post- and preinjection D(2) occupancy levels for the 25-, 50-, and 75-mg doses were 71.0% and 54.0%, 74.4% and 65.4%, and 81.5% and 75.0%, respectively. There was a significant correlation between dose and plasma concentrations of risperidone plus 9-hydroxyrisperidone, and the estimated plasma concentration associated with 50% D(2) occupancy (ED(50)) was 11.06 ng/ml. Prolactin levels were not correlated with drug levels or D(2) occupancy. CONCLUSIONS: All three doses of injectable risperidone showed peak D(2) occupancy levels above the 65% threshold associated with optimal clinical response; the 75-mg dose approximated the 80% threshold linked to increased risk of extrapyramidal symptoms. Doses of 25 or 50 mg should provide therapeutic efficacy while minimizing the risk of extrapyramidal symptoms.

Adult↗
PubMed2004

A PET study of dopamine D2 and serotonin 5-HT2 receptor occupancy in patients with schizophrenia treated with therapeutic doses of ziprasidone.

OBJECTIVE: Ziprasidone is an atypical antipsychotic drug that shows a higher affinity for serotonin 5-HT(2) receptors compared with dopamine D(2) receptors in vitro. The affinity of ziprasidone for these receptors in vivo in patients was examined in a positron emission tomography (PET) study. METHOD: The authors conducted a PET study to evaluate D(2) occupancy (using [(11)C]raclopride) and 5-HT(2) occupancy (using [(18)F]setoperone) in brain regions of interest in 16 patients with schizophrenia or schizoaffective disorder randomly assigned to receive 40, 80, 120, or 160 mg/day of ziprasidone, which reflected the recommended dose range. PET scanning was done after 3 weeks of administration and at trough plasma levels, i.e., 12-16 hours after the last dose. RESULTS: The mean 5-HT(2) receptor occupancy was significantly higher than the mean D(2) receptor occupancy (mean=76%, SD=15%, and mean=56%, SD=18%, respectively). The estimated plasma ziprasidone concentration associated with 50% maximal 5-HT(2) receptor occupancy was almost four times lower than that for D(2) receptor occupancy. CONCLUSIONS: These data affirm that ziprasidone is similar to other novel antipsychotics in having greater 5-HT(2) than D(2) receptor occupancy at therapeutic doses and suggest that the optimal effective dose of ziprasidone is closer to 120 mg/day than to the lower doses suggested by previous PET studies. The relatively high D(2) receptor occupancy, even at trough plasma levels, suggests that ziprasidone is more similar to risperidone and olanzapine in receptor occupancy profile than to clozapine and quetiapine. Since ziprasidone plasma levels show significant (more than twofold) variation within a single dose cycle, studies that are aimed at peak plasma levels (6 hours after the last dose) and that examine extrastriatal regions are required to fully characterize the in vivo occupancy profile of ziprasidone.

Adult↗