Clozapine-induced pulmonary embolism in a patient with minimal pre-existing risk factors.

OBJECTIVES: Although the risk of antipsychotic-induced venous thromboembolism (VTE) has been definitively established, guidelines recommending prophylactic anticoagulation do not yet exist. Several algorithms have been proposed that suggest possible prophylaxis with an anticoagulant medication on the basis of pre-existing VTE risk factors. We present a case of antipsychotic-induced VTE despite the patient's low-risk status so that practitioners may better understand which factors may or may not constitute a major risk in this population when making a determination about prophylactic anticoagulation. CASE SUMMARY: We present a patient case of a 56-year-old man with schizoaffective disorder who was treated with clozapine at an inpatient psychiatric unit. Although he would be classified as low risk for VTE on the basis of the proposed algorithms, he experienced a pulmonary embolism by day 17 of treatment and required transfer to a medical unit. This patient displayed sensitivity to other adverse effects associated with clozapine during his treatment course, including tachycardia, sialorrhea, enuresis, and bowel obstruction. PRACTICE IMPLICATIONS: Many of the known risk factors for antipsychotic-induced VTE were not present in this patient, including immobility, hyperprolactinemia, and coagulation abnormalities. The recent initiation of clozapine and obesity seem to be the only identified risk factors, although malignancy and abnormal antiphospholipid antibody levels were not able to be ruled out. It is difficult to determine if this patient experienced a VTE owing to a relatively high degree of sensitivity to clozapine, as evidenced by the myriad of other adverse effects that he experienced. This case highlights the need to determine true antipsychotic-induced VTE risk factors, including evaluation of comorbid adverse effects that occur in addition to the VTE. This information will help to guide future decision-making regarding the risk versus benefit of providing prophylactic anticoagulation for patients during initiation of antipsychotic treatment.

Competition between the heavy atom effect and vibronic coupling in donor-bridge-acceptor organometallics.

The excited state properties and intersystem crossing dynamics of a series of donor-bridge-acceptor carbene metal-amides based upon the coinage metals Cu, Ag, Au, are investigated using quantum dynamics simulations and supported by photophysical characterisation. The simulated intersystem rates are consistent with experimental observations making it possible to provide a detailed interpretation of the excited state dynamics which ultimately control their functional properties. It is demonstrated that for all complexes there is a competition between the direct intersystem crossing occurring between the 1CT and 3CT states and indirect pathways which couple to an intermediate locally excited ππ* triplet state (3LE) on either the donor or acceptor ligands. The energy of the 3LE states decreases as the size of the metal decreases meaning that the indirect pathway plays an increasingly important role for the lighter metals. Importantly whenever the direct pathway is efficient, the presence of indirect pathways is detrimental to the overall rate of ISC as they provide a slower alternative pathway. Our results provide a detailed insight into the mechanism of intersystem crossing in these complexes and will greatly facilitate the design of new higher performing molecules.

Tailored Interface Energetics for Efficient Charge Separation in Metal Oxide-Polymer Solar Cells.

Hybrid organic-inorganic heterointerfaces in solar cells suffer from inefficient charge separation yet the origin of performance limitations are widely unknown. In this work, we focus on the role of metal oxide-polymer interface energetics in a charge generation process. For this purpose, we present novel benzothiadiazole based thiophene oligomers that tailor the surface energetics of the inorganic acceptor TiO2 systematically. In a simple bilayer structure with the donor polymer poly(3-hexylthiophene) (P3HT), we are able to improve the charge generation process considerably. By means of an electronic characterization of solar cell devices in combination with ultrafast broadband transient absorption spectroscopy, we demonstrate that this remarkable improvement in performance originates from reduced recombination of localized charge transfer states. In this context, fundamental design rules for interlayers are revealed, which assist the charge separation at organic-inorganic interfaces. Beside acting as a physical spacer in between electrons and holes, interlayers should offer (1) a large energy offset to drive exciton dissociation, (2) a push-pull building block to reduce the Coulomb binding energy of charge transfer states and (3) an energy cascade to limit carrier back diffusion towards the interface.

Eczema and allergy: how useful is allergy testing?

AIM: To determine the value of allergy testing using skin prick tests and specific immunoglobulin E measurements (spIgE) to identify allergies in children with eczema (atopic dermatitis) and to correlate these findings with the clinical history METHOD: This was a retrospective study of 100 children with moderate to severe eczema attending hospital for treatment. In each child a detailed clinical history of allergy was documented and the severity of atopic dermatitis assessed by the research nurse. Skin prick tests were carried out using grass pollen, house-dust mite and egg-white allergens. Blood tests were taken for total IgE and spIgE responses to these allergens. A control group of 100 children with no history of allergy was also included for comparison. RESULTS: More than two thirds of the children (68 per cent) had a high total IgE (> 1000 kU/l). SpIgE tests to grass and house-dust mite were shown as the most frequent finding although statistically poor in association with the clinical history. Allergy to these airborne allergens was found to be more common in the older age group of children. whereas egg-white allergy was seen more commonly in the younger age group. CONCLUSION: There is no one diagnostic test for allergy in children with atopic dermatitis. The results of these tests in combination with the clinical history provide a more accurate assessment of the child's allergy status. Children with moderate to severe eczema have a high incidence of associated allergy. Skin prick tests and spIgE proved helpful but neither was exclusively better than the other for diagnosis. The clinical nurse specialist is able to make a valuable contribution to the family through offering support and carrying out allergy tests.