Electrolytic complexing of glucoheptonate and technetium-99m.

Solutions of glucoheptonate and sodium pertechnetate (Tc-99m) were subjected to electrolysis at various ampere-time products until a charge was found that consistently promoted tagging of greater than 90% efficiency. It was found that 9 coulombs (100 mA, 90 sec) consistently yielded a final product that contained less than 10% total radiochemical impurities (unbound pertechnetate and reduced, hydrolyzed technetium). Radiochemical purity of the final product was established using a two-solvent thin-layer chromatographic system with methyl-ethyl ketone and normal saline as the solvents. The tagging efficiency and stability of the tagged complex were determined with similar chromatographic analysis. It was shown that use of a 15% solution of calcium glucoheptonate resulted in a more stable product than that prepared from commercially available stannous glucoheptonate. The rapid, accurate chromatographic method for determination or radiochemical purity of the product is described. The final product is considered equal or superior to commercial Tc-99m (Sn) glucoheptonate and was produced at considerably less cost.

Antidepressant treatment of children: clinical relapse is unrelated to tricyclic plasma concentrations.

Plasma concentrations of imipramine and amitriptyline and their desmethylated metabolites were measured in 20 children being treated for major depressive illness 2 wk. and 5 to 10 wk. after achieving drug dosages of 2.25 mg/kg body weight. At 2 wk. all children had exhibited clinical improvement, but by 10 wk. 4 of the 10 children treated with imipramine and 5 of the 10 children treated with amitriptyline had experienced clinical relapse of depressive symptoms. Tricyclic antidepressant plasma concentrations and ratios were comparable in the subgroups of children who maintained their clinical improvement and those who relapsed. There was no evidence of a systematic decline in plasma tricyclic antidepressant concentrations in those children who relapsed.

Evaluation of therapeutic drug monitoring in a long-term care facility: a pilot project.

The need for a therapeutic drug monitoring service was evaluated in a 150-bed long-term care facility. Thirty blood samples from 28 residents (mean age 87.9 years) were assayed to determine trough drug concentrations. All subjects were examined to determine pharmacodynamic effect. Pharmacokinetic consultations were written for serum drug concentrations outside accepted ranges. Fifty percent (15 of 30) of serum drug levels measured were subtherapeutic; the remaining levels were in the normal therapeutic range. Based on this sample data, it could be concluded that a minimum of 32 percent and as many as 68 percent of serum drug levels would be subtherapeutic following drug analysis in similar nursing home populations. Of 12 consultations, recommendations for seven (58 percent) were accepted by the subject's primary care physicians. Four of the consultations (33 percent) resulted in dosage modifications. These results support the need for further study.