An 1H NMR study of the cytarabine degradation in clinical conditions to avoid drug waste, decrease therapy costs and improve patient compliance in acute leukemia.

Cytarabine, the 4-amino-1-(ß-D-arabinofuranosyl)-2(1H)-pyrimidinone, (ARA-C) is an antimetabolite cytidine analogue used worldwide as key drug in the management of leukaemia. As specified in the manufacturers' instructions, once the components-sterile water and cytarabine powder-are unpackaged and mixed, the solution begins to degrade after 6 hours at room temperature and 12 hours at 4°C. To evaluate how to avoid wasting the drug in short-term, low-dose treatment regimens, the reconstituted samples, stored at 25°C and 4°C, were analyzed every day of the test week by reversed-phase HPLC and high-field NMR spectroscopy. All the samples remained unchanged for the entire week, which corresponds to the time required to administer the entire commercial drug package during low-dose therapeutic regimens. The drug solution was stored in a glass container at 4°C in an ordinary freezer and drawn with sterile plastic syringes; during this period, no bacterial or fungal contamination was observed. Our findings show that an cytarabine solution prepared and stored in the original vials retains its efficacy and safety and can, therefore, be divided into small doses to be administered over more days, thus avoiding unnecessary expensive and harmful waste of the drug preparation. Moreover, patients who require daily administration of the drug could undergo the infusion at home without need to go to hospital. The stability of the aliquots would help decrease hospitalization costs.

Detection of increased left ventricular filling pressure by pulsed tissue Doppler in cardiac amyloidosis.

OBJECTIVE: The aim of this study was to evaluate the incremental diagnostic role of tissue Doppler in primary cardiac amyloidosis (CA). METHODS: Eleven patients with CA at diagnosis and 11 healthy controls, matched for sex and age, underwent standard Doppler echocardiography and pulsed tissue Doppler of the left ventricular (LV) lateral annulus, in the apical four-chamber view. The ratio of early transmitral flow velocity to early diastolic mitral annular velocity (E/E(m) ratio) was derived as an index of LV filling pressure. RESULTS: The two groups were comparable for body mass index, blood pressure, heart rate and standard Doppler diastolic measurements. Patients with CA had a significantly higher sum of wall thickness (SWT) and LV mass, a lower E(m) peak velocity (P < 0.002) and a higher E/E(m) ratio (P < 0.001) than controls. By dividing CA patients according to the transmitral E/A ratio, patients with an E/A ratio < 1 (abnormal relaxation) (n = 5) and patients with an E/A ratio > 1 (likely pseudonormal/restrictive pattern) (n = 6) did not show any difference in the E/E(m) ratio (14.5 + or - 7.1 vs. 15.1 + or - 6.4, P = NS). In the overall population, the E/E(m) ratio was related to SWT (r = 0.84, P < 0.0001) and LV mass index (r = 0.72, P < 0.0001). After adjusting for age and heart rate by separate multivariate models, SWT (beta = 0.78, P < 0.0001; cumulative r(2) = 0.63, SE = 3.38, P < 0.0001) and LV mass index (beta = 0.71, P < 0.0001; cumulative r(2) = 0.53, SE = 3.80, P < 0.002) were both independently associated with the E/E(m) ratio. CONCLUSIONS: Pulsed tissue Doppler is able to detect early myocardial diastolic impairment in CA. The E/E(m) ratio is very useful in diagnosing increased LV filling pressure, regardless of the transmitral pattern, and may, therefore, be helpful in the clinical management of these patients.