Physician versus computer knowledge of potential drug interactions in the emergency department

INTRODUCTION

Proliferation of Food and Drug Administration-approved drugs makes it impossible for emergency medicine (EM) faculty to stay current on potential interactions between drugs, and with diseases, laboratory tests, and ethanol. A computer database may augment physician knowledge.

OBJECTIVES

To compare the performance of EM faculty and an "expert" emergency physician (EP) with that of a criterion standard computer database in identifying potential drug interactions, and to report the incidence of drug-ethanol and drug-laboratory test interactions.

METHODS

This was a retrospective review of 276 emergency department charts for drug, ethanol, lab, and medical history. Evaluation by both EM faculty and an "expert" EP of patient history was done to identify potential interactions, and comparison with the Micromedex Drug-Reax database for potential interactions (graded minor, moderate, or major) was made. Clinical significance of potential interactions was judged by a second EM faculty member.

RESULTS

Seventeen percent of the patients had potential drug-drug interactions, and 25% of these were judged to be clinically significant. Up to 52% of the patients had potential drug-ethanol interactions, while 38% of the patients could have potential drug-lab interactions. Sensitivity, specificity, and positive and negative predictive values of the EM faculty for potential drug-drug interactions compared with the computer were poor, at 14%, 58%, 6%, and 23%, respectively. The corresponding values for the "expert" EP were 25%, 86%, 26%, and 85%. The "expert" EP was statistically better than the EM faculty, but still less sensitive and predictive than the computer.

CONCLUSIONS

A computer can aid the physician in avoiding potential drug interactions. Prospective validation of these findings should be done.

Chromatin organization and breast cancer prognosis. Two-dimensional and three-dimensional image analysis

BACKGROUND

The assessment of breast cancer prognosis still relies on clinical staging and histologic grading. Among the different prognostic parameters, attention has been focused on features of chromatin structure. Although data from two-dimensional (2-D) analysis of chromatin structure show significant correlation with the survival, their biologic interpretation remains difficult. In this respect, insights into the spatial organization of chromatin appear important.

METHODS

The authors performed computerized three-dimensional (3-D) reconstructions of Feulgen-stained tumor cell nuclei, correlating the results with those of 2-D image analysis. Forty-nine ductal-invasive carcinomas with 10-18 years follow-up were investigated.

RESULTS

The 2-D analysis demonstrated that along with nuclear size and shape, chromatin features such as marginal concentration of condensed chromatin are of prognostic importance. As 3-D analysis revealed, chromatin changes concern ordered organization and were associated with the increase of spatial entropy.

CONCLUSIONS

The 3-D description of chromatin structure by means of spatial models provides evidence that tumor aggressiveness correlates with events of clustering and randomization. These indicate disturbances of ordered chromatin organization.

Bone banking. A cost effective method for establishing a community hospital bone bank

Both cost effectiveness and safety can be realized in the operation of a community bone bank by adoption of the following measures: deep freezing, rather than freeze drying; allogenic bone is collected from femoral heads excised from total hip arthroplasties; and careful donor and graft selection controls ensure an allograft free of disease which can be transmitted to the recipient. Two-year follow-up data reveal no complications or infections from implantation of 101 allografts.

Distribution of anticancer agents in spontaneous animal tumors. II. Distribution of gallium in canine lymphosarcoma

The physiologic disposition of pharmacologic doses of gallium was studied in control dogs and dogs with spontaneous lymphosarcoma. Gallium 67 (67Ga) was administered iv with carrier gallium added at a dose of 8 mg/kg. About 50% of the injected dose was excreted in the urine by 48 hours (mostly in the first 12 hr), whereas negligible amounts were excreted in bile. The distribution of 67Ga in normal tissues was similar in control and tumor-bearing dogs. The tissue-to-plasma concentrations of gallium were considerably greater than 1 in the kidney cortex, bone marrow, bone, small intestine, and liver 6-72 hours after administration of the drug. At comparable time periods, tissue-to-plasma ratios of gallium were less than 1 in skeletal muscle and brain. In dogs with lymphosarcoma there was neither selective uptake nor selective retention of gallium in comparison to most normal tissues. In fact, several normal tissues, particularly kidney cortex and bone marrow, concentrated gallium greatly in excess of tumors. Qualitatively similar findings were obtained in a dog with malignant melanoma. These findings were contrary to what one would predict from reports showing that carrier-free 67Ga is selectively concentrated in various human and animal tumors. This indicates the need for more extensive studies of the physiologic disposition of pharmacologic (antitumor) doses of gallium in humans and appropriate animal models.

The kinetics of methotrexate distribution in spontaneous canine lymphosarcoma

A mathematical model is presented to simulate the time-dependent uptake of methotrexate in spontaneous canine lymphosarcomas in vivo. Blood flow ratew in these tumors are high so that transport to the tumor is limited by cell membrane resistance. A significant amount of rapidly exchangeable methotrexate appears to exist in extracellular space loosely bound to proteins or cell membranes. Transmembrane drug transport follows Michaelis-Menten kinetics, wigh the maximum facilitated transport ranging from 0.002 to 0.007 mug/min/ml for the separate tumors studied and a Michaelis constant for transport equal to 0.2 mug/ml. This is in the range of Michaelis constants reported for normal tissues in rats in vivo and in several cell linnes in vitro.

Antitumor activity and toxicity of salts of inorganic group 3a metals: aluminum, gallium, indium, and thallium

The toxicity and antitumor activity of salts of the Group IIIa metals aluminum, gallium, indium, and thallium were determined. With the (lethal dose)(50) as a measure, the decreasing order of toxicity was TlCl(3) >/= In(NO(3))(3) > Ga(NO(3))(3) > Al(NO(3))(3). All four metals exhibited antitumor activity, but when the tumor was inoculated by a route different from that of the drug, only Ga(+3) and, to a lesser extent, In(+3) inhibited tumor growth. Ga(NO(3))(3) was found to inhibit the growth of three out of four rodent solid tumors. Gallium therefore has potential therapeutic usefulness for treatment of solid tumors in man.