The effects of intravenous theophylline infusion versus intravenous sodium bicarbonate infusion on lithium clearance in normal subjects.

Ten normal subjects ingested lithium carbonate (600 mg p.o. b.i.d.) for three 1-week intervals. At the end of each weekly interval, subjects' lithium clearances were randomly perturbed for 12 hours with the subject in a supine position by infusing either normal saline (308 mEq), sodium bicarbonate (350 mEq) in normal saline (308 mEq), or theophylline (mean = 14.0 micrograms/ml) in normal saline (308 mEq). Subjects were placed on a 200 mEq/day sodium diet during the lithium clearance perturbation stages of the study. When each patient's normal saline lithium clearance was used as a control, it was found that the theophylline produced a significantly greater % increase in lithium clearance than did the sodium bicarbonate. Theophylline infusions increased patients' individual lithium clearances by 51 +/- 52%, while sodium bicarbonate infusions increased lithium clearances by 0.6 +/- 33%. Theophylline infusions ought to be investigated as an alternative to hemodialysis in lithium intoxications requiring the immediate reduction of lithium concentrations.

Enhanced adrenal sensitivity to exogenous cosyntropin (ACTH alpha 1-24) stimulation in major depression. Relationship to dexamethasone suppression test results.

ACTH alpha 1-24 (cosyntropin) (250 micrograms by intravenous bolus) was given to 38 medicated patients with major depressive disorder (MDD) and to 34 normal control subjects. Patients with MDD had significantly higher plasma cortisol concentrations and significantly higher increases in plasma cortisol levels 60 minutes after cosyntropin infusion than did control subjects. Patients who were nonsuppressors in the dexamethasone suppression test had significantly higher 60-minute cortisol concentrations and cortisol increases than did normal subjects and patients with MDD who were suppressors. There were significant, strongly positive correlations between cortisol secretory responses to cosyntropin and postdexamethasone cortisol concentrations in patients with MDD. These findings confirm that adrenal sensitivity to corticotropin (ACTH) is enhanced in MDD and suggest that this endocrine abnormality may be related pathophysiologically to the resistance of cortisol secretion to dexamethasone suppression.

Exacerbation of acute intermittent porphyria by nortriptyline.

Many medications have been reported to produce attacks of acute intermittent porphyria (AIP). Nortriptyline has been reported to be safe in porphyric patients. We present a case of AIP exacerbated by nortriptyline.