Relative bioavailability of aspirin gum.

The bioavailability of aspirin gum relative to unbuffered aspirin tablets was determined in six normal volunteers. Twenty-four hours following the administration of two aspirin tablets, 91.2 +/- 1.

Stability of trimethoprim-sulfamethoxazole injection in two infusion fluids.

The concentrations over time of trimethoprim (TMP) and sulfamethoxazole (SMZ) in solution after preparations of admixtures of TMP-SMZ in 5% dextrose injection (D5W) and in 0.9% sodium chloride injection (NS) were measured. Admixtures (50 ml) containing three TMP concentrations (0.

Theophylline serum protein binding in obstructive airways disease.

The percentage of theophylline bound to protein in sera obtained from patients with obstructive airways disease was determined by ultrafiltration. The bound theophylline fraction in 71 serum specimens collected from 51 patients was 60.7 +/- 10.

Procainamide interference with liquid chromatography of theophylline in serum.

We described potential interference of procainamide with our high pressure liquid chromatography procedure for assaying theophylline (similar to that given by Orcutt et al.). In participating in the AACC-TDM quality-control program, we discovered procainamide interference on a column dedicated to theophylline and acetaminophen serum analyses.

Effect of cholesterol content on antitumor activity and toxicity of liposome-encapsulated 1-beta-D-arabinofuranosylcytosine in vivo.

1-beta-D-Arabinofuranosylcytosine (ara-C) was encapsulated in anionic multilamellar liposomes prepared with different lecithin: cholesterol (L:C) ratios. The chemotherapeutic activity of encapsulated ara-C was compared with comparable doses of ara-C in 0.85% saline solution (single- and multiple-dose schedules) in mice bearing L1210 (i.

Temporal variations in trough serum theophylline concentrations at steady state.

Temporal variations in serum theophylline concentrations were observed in 14 healthy volunteers receiving multiple doses of theophylline. After repeated oral doses (6.9--18.

Two reasons for unusual therapeutic drug monitoring results in hospitalized patients.

In programs where therapeutic drug monitoring is accompanied by interpretation of the data, unusual and unanticipated values may mean more than just a laboratory error. Many times such spurious results will be due to unusual circumstances that result in the drug never reaching the bloodstream. In 3 case reports, we show that purposeful inhospital noncompliance and failure to recognize simple drug absorption interactions can be added to the evergrowing list of factors influencing serum concentrations of therapeutic agents.

Pharmacokinetics and relative bioavailability of oral theophylline capsules.

The oral bioavailability of liquid-filled theophylline capsules relative to a nonalcoholic aminophylline solution was determined in normal volunteers. In addition, theophylline absorption and elimination kinetics were reexamined. There were no statistically significant differences between the bioavailability of capsules and liquid as measured by the area under the curve (AUC) from time 0 leads to infinity (p greater than 0.

Dose-dependent elimination kinetics of theophylline.

There are an increasing number of clinical and experimental studies appearing in the literature suggesting that the elimination kinetics of theophylline may be dose-dependent in man. Evidence of nonlinearity includes observations that steady-state serum theophylline concentrations may increase disproportionately with increases in dose and that the elimination half-life of theophylline after multiple doses is longer than after single doses. Theophylline is apparently eliminated by parallel Michaelis-Menten and first-order kinetics.

Hormone action at the membrane level. IV. Epinephrine binding to rat liver plasma membranes and rat epididymal fat cells.

[3-H]Epinephrine binding to isolated purified rat liver plasma membranes is a reversible process. An initial peak in binding occurs at about 15 min and a plateau occurs by 50 min. Optimal binding occurred at a membrane protein concentration of 125mug.