Pharmacokinetics of hydroxyethyl starch in normal subjects

To determine the elimination of high-molecular-weight hydroxyethyl starch (HES, Mw 450,000) in normal subjects, ten volunteers were given 500 ml 6% HES solution by intravenous infusion, and serial blood and urine samples were collected for nonglucose total carbohydrate determination. On the average, 46 and 64 per cent of the dose was excreted in the urine within two and eight days, respectively. The plasma concentration declined rapidly during the first week after infusion. The average terminal half-life was 17 days during the first 42 days, which accounted for elimination of about 90 per cent of the dose. The remainder was eliminated with a terminal half-life of 48 days determined between days 42 and 83 of the study. As expected, the infusion of HES resulted in plasma volume expansion over a 48-hour period during which time levels of nonglucose carbohydrates were above 3.5 mg/ml. HES is metabolized by alpha-amylase in the body. During the first 48 hours after infusion of HES, plasma alpha-amylase activity was significantly increased over control. Concomitantly, alpha-amylase activity in urine was also elevated but not significantly so.

Bioavailability of N-acetylprocainamide from mixed diet in rats

The purpose of this study was to determine the bioavailability of N-Acetylprocainamide (NAPA) from mixed diet in rats. Six groups of 8 male Charles River CD rats received NAPA-HCl as follows: Group I, an intravenous dose (mean 21 mg) of 14C-labelled drug. Group II, in a solution given by oral gavage with and without feed (50 mg) in a two-way crossover fashion. Groups III-VI, incorporated in diet (42-68 mg). Urine and feces were collected for 48 hours and assayed for NAPA and procainamide by a specific HPLC method. On the average, 73% of the drug was eliminated unchanged in urine. Only a small percentage (3-4%) of the intact drug was recovered in feces after intravenous or oral administration. There were no detectable levels of procainamide in urine and feces. The absolute bioavailability of NAPA from oral solution with and without feed was 87 and 90%, respectively, and from the mixed diet was 84-92%. There was no statistically significant difference between the bioavailability of NAPA from solution in fasted and fed rats or from NAPA-mixed diet, indicating that the absorption of the drug in rats was not affected by food. The relative bioavailability of the drug from mixed diet ranged from 94-103%.

Pharmacokinetics of procainamide and N-acetylprocainamide in rats

The pharmacokinetics of distribution and elimination of procainamide and its major metabolite, N-actylprocainamide, were studied in rats. Eight rats were selected randomly, and each received intravenously 14C-labeled procainamide hydrochloride (75 mg/kg) or 14C-labeled N-acetylprocainamide hydrochloride (86 mg/kg) according to a two-way crossover design. Serial blood samples were withdrawn for 8 hr, and cumulative urine and feces were collected for 48 hr. The plasma concentration-time relationships of procainamide and N-acetylprocainamide were characterized by one- and two-compartment open models, respectively. A pseudo-three-compartment model was necessary to characterize the time course of N-acetylprocainamide in plasma formed after administration of procainamide. The biological half-lives of procainamide and N-acetylprocainamide averaged 0.66 and 2.1 hr, respectively. The urinary excretion profiles of these drugs and the ratio of their biological half-lives in rats were similar to those in humans.

Effect of coronary artery ligation on the pharmacokinetics of N-acetylprocainamide in dogs

The effect of ligation of the left anterior descending and septal coronary arteries on the distribution of N-acetylprocainamide (NAPA) was studied in 13 mongrel dogs. The animals received a rapid i.v. infusion of 20 mg/kg NAPA.HCl. In 6 dogs the arteries were ligated simultaneously 10 min after administration of the drug. The other dogs received the same dose without anesthesia or surgery and served as control. Coronary ligation procedure resulted in a significantly higher initial plasma concentration of NAPA, presumably because of a significant decrease in the apparent volume of central compartment. The biologic half-life, the apparent volume of distribution and the total clearance of the drug remained unchanged in both groups of animals. The results of this study suggest that while the pharmacokinetics of elimination of NAPA remain unchanged, the distribution and the effective plasma concentration might be altered by the coronary ligation procedure under anesthesia.

Effect of thiamine hydrochloride on the blood level of 2-formyl 1-methyl pyridinium oxime chloride (2-PAM.C1) in rats

The biological half-life of 2-PAM.C1 was found to increase in female rats pretreated with thiamine hydrochloride (10 mg/kg i.m.). No such effect was observed in the male rats.

Acute ischaemic enteritis in Goa

Acute ischaemic enteritis is an uncommon condition which mainly affects young people. It is characterized by ischaemic changes in the small or large bowel which may be reversible in the early stages. The exact aetiology is not known. The condition may be due to toxins produced by either roundworms or Gram-negative bacilli or may be due to a localized allergic reaction. It is possible to make a preoperative diagnosis in most cases from the presence of abdominal pain, bloody diarrhoea and shock. Conservative treatment may be best in early cases but surgery is necessary in those cases where gangrene or perforation has occurred.

Effect of ascorbic acid on histamine metabolism in scorbutic guinea-pigs

1. In guinea-pigs fed an ascorbic-acid-free diet, as the ascorbic acid levels decreased the histamine levels in blood and urine rose steadily to maxima in about 10-12 days. The elevated histamine levels persisted in the blood and urine of scorbutic guinea-pigs and the histamine levels in lung, gastric mucosa and spleen also increased. The increased histamine content of the urine, blood and other tissues in the ascorbic-acid-depleted condition could be brought back to normal levels by administration of a single dose of ascorbic acid 5 mg/100 g body wt. guinea-pig. 3. The drop in the elevated histamine level was not due to an indirect effect of ascorbic acid on histamine forming capacity, histaminase activity or histamine release.

Cavernous haemangioma of the frontal bone: case report

A rare of haemangioma of the frontal bone is presented together with a review of the literature. Carotid angiography was found to be a useful diagnostic aid to differentiate if from other lesions of the frontal bone. The best treatment is to excise both tables containing the haemangioma together with a rim of healthy bone in one block.