No abstract

A study of a dopaminergic antidepressant that may have an advantageous profile for use in elderly patients, bupropion, was conducted to determine the pharmacokinetics of bupropion in the elderly. Pharmacokinetics of single- and multiple-dose bupropion were examined in six elderly patients (five women and one man) diagnosed with depression. Mean (+/- SD) CL app of bupropion was 1.6 +/- 0.4 L/hr/kg, approximately 80% of the corresponding value reported for younger patients. Mean bupropion t1/2 was 34.2 +/- 8.7 hours, and average apparent Vd (Vd app) was 79.3 +/- 29.4 L/kg. Apparent half-lives (t1/2 app) of the metabolites hydroxybupropion, erythrobupropion, and threohydrobupropion were 34.2 +/- 4.6 hours, 61.4 +/- 21.6 hours, and 38.8 +/- 7.6 hours, respectively. After multiple dosing, the mean t1/2 for bupropion and its metabolites did not change significantly, although in some patients the t1/2 app of the metabolites was substantially prolonged. There was also evidence of inordinate accumulation of metabolites. The elderly are at risk for accumulation of bupropion and its metabolites. Specification of therapeutic drug monitoring parameters for bupropion treatment of the elderly is needed.

The source of the background hydrocarbons in benthic sediments of Prince William Sound (PWS), AK, where the 1989 Exxon Valdez oil spill (EVOS) occurred, has been ascribed to oil seeps in coastal areas of the Gulf of Alaska (GOA). We present evidence that coal is a more plausible source, including (i) high concentrations of total PAH (TPAH), between 1670 and 3070 ng/g, in continental shelf sediments adjacent to the coastal region containing extensive coal deposits; (ii) PAH composition patterns of sediments along with predictive models that are consistent with coal but not oil; (iii) low ratios (<0.2) of triaromatic steranes to methylchrysenes found in sediments and coals, contrasting with the high ratios (11 and 13) found in seep oil; and (iv) bioaccumulation of PAH in salmon collected within 100 m of the Katalla oil seeps but not in filter-feeding mussels collected near oilfield drainages 9 km from the seeps, indicating negligible transport of bioavailable PAH from Katalla seeps to the GOA. In contrast with oil, PAH in coal are not bioavailable, so the presence of coal in these benthic sediments confers no adaptive benefit to biota of the marine ecosystem with respect to PAH insults from anthropogenic sources.