Loss of carbamazepine suspension through nasogastric feeding tubes

The apparent loss of carbamazepine suspension during administration through polyvinyl chloride nasogastric feeding tubes in vitro was studied. Twelve methods of administering carbamazepine suspension (100 mg/5 mL) were tested; the methods differed with respect to nasogastric tube size, presence and type of diluent, and type of flush solution. Undiluted or 50% diluted carbamazepine suspension 200 mg was drawn up in a syringe and forced through adult or pediatric nasogastric feeding tubes. The tubes were immediately flushed twice with 50 mL of sterile water, 0.9% sodium chloride solution, or 5% dextrose solution, by using the same syringe used to administer the suspension. Samples were collected and analyzed for carbamazepine concentration by high-performance liquid chromatography. Each administration method was tested six times, and the results were subjected to analysis of variance. Significant loss of carbamazepine was noted for four of the six methods in which undiluted suspension was administered. In these methods, adult and pediatric tubes were flushed with sterile water or 0.9% sodium chloride. No significant loss of drug occurred for any of the methods involving the use of diluent. Significant losses were associated with diluent and flush solution but not nasogastric tube size. Carbamazepine suspension should be mixed with an equal volume of diluent before being administered through nasogastric feeding tubes.     

Respiratory chemoreflexes and effects of cortical activation state in urethane anesthetized rats

Urethane anesthetized (< 1 .3 g/kg), Sprague-Dawley (SD) rats spontaneously cycled between a cortically desynchronized state (State I) and a cortically synchronized state (State III), which were very similar to awake and slow wave sleep (SWS) states in unanesthetized animals, based on EEG criteria. These low levels of urethane anaesthesia did not cause significant respiratory depression or reductions in sensitivity to hypoxia (10% O2 in nitrogen) or hypercapnia (5% CO2 in air) in rats in either State I or State III. Thus, breathing frequency (fR), tidal volume (VT) and total ventilation (VTOT) all increased on cortical activation in urethane-anaesthetized rats whether breathing air, the hypoxic or the hypercapnic gas mixture, in a manner that was very similar to that observed in unanaesthetized animals. The relative sensitivity to hypoxia was greater in State III than State I, the relative sensitivity to CO2, overall, was equal in both states, State III occurred less often during hypoxia and hypercapnia, and hypoxic, urethane-anaesthetized rats sighed frequently, particularly in State I. This is also similar to the situation seen in unanesthetized rats. Given the similarities seen between urethane anesthetized rats in the present study and literature values for unanesthetized rats, the data suggest that urethane-anaesthetized rats provide a good model system for studying respiratory patterns and chemoreflexes as a function of cortical activation state.     

A clinical study of flurazepam

Eleven patients suffering from chronic insomnia were given 30 mg flurazepam for 28 nights. While EEG measures of total sleep time and sleep efficiency were improved, changes in sleep latency and intermittent waking time were small and nonsignificant. Subjective benefits in sleep were confined to the first 2 nights. There was neither increased nor decreased daytime sleepiness. Cognitive functioning was significantly decreased during the first 2 days, and patients were unaware of these changes. Simple motor tasks were relatively unaffected. Desalkylflurazepam concentrations showed significant accumulation over time, but were not predictive of sleep measures or daytime performance in individual subjects. The withdrawal period was characterized by subjectively disturbed sleep and daytime dysphoria.     

New York University Medical Center's Cooperative Care Unit: patient education and family participation during hospitalization--the first ten years

The New York University Medical Center Cooperative Care (CC) program is a model of a delivery system of acute inpatient hospital care characterized by a live-in family member or friend acting as a "care partner". It has an emphasis on education in order to encourage full patient and family involvement in care during the acute hospitalization, thereby preparing both parties for management at home after discharge. The education-intensive experience of CC provides an alternative to traditional inpatient hospital care with the expected outcome of CC being to increase patient and family knowledge and satisfaction, adherence to the medical regimen, and appropriate self-management. The functioning ability of the patient-care partner team should be improved on discharge, which may result in decreased subsequent utilization of high cost healthcare resources such as rehospitalization. This paper describes the structure of the CC form of inpatient care, the types of patients appropriate for such care, and the experience of its first ten years of operation, with its implications as a replicable model for other institutions.     

Surface Modification of Poly(lactide-co-glycolide) Nanospheres by Biodegradable Poly(lactide)-Poly(ethylene glycol) Copolymers

The modification of surface properties of biodegradable poly(lactide-co-glycolide) (PLGA) and model polystyrene nanospheres by poly(lactide)-poly(ethlene glycol) (PLA:PEG) copolymers has been assessed using a range of in vitro characterization methods followed by in vivo studies of the nanospheres biodistribution after intravenous injection into rats. Coating polymers with PLA:PEG ratio of 2:5 and 3:4 (PEG chains of 5000 and 2000 Da, respectively) were studied. The results reveal the formation of a PLA: PEG coating layer on the particle surface resulting in an increase in the surface hydrophilicity and decrease in the surface charge of the nanospheres. The effects of addition of electrolyte and changes in pH on stability of the nanosphere dispersions confirm that uncoated particles are electrostatically stabilized, while in the presence of the copolymers, steric repulsions are responsible for the stability. The PLA:PEG coating also prevented albumin adsorption onto the colloid surface. The evidence that this effect was observed for the PLA:PEG 3:4 coated nanospheres may indicate that a poly(ethylene glycol) chain of 2000 Da can provide an effective repulsive barrier to albumin adsorption. The in vivo results reveal that coating of PLGA nanospheres with PLA:PEG copolymers can alter the biodistribution in comparison to uncoated PLGA nanospheres. Coating of the model polystyrene nanospheres with PLA:PEG copolymers resulted in an initial high circulation level, but after 3 hours the organ deposition data showed values similar to uncoated polystyrene spheres. The difference in the biological behaviour of coated PLGA and polystyrene nanospheres may suggest a different stability of the adsorbed layers on these two systems. A similar biodistribution pattern of PLA:PEG 3:4 to PEG 2:5 coated particles may indicate that poly(ethylene glycol) chains in the range of 2000 to 5000 can produce a comparable effect on in vivo behaviour.