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Biomedical subjects

N Buchanan

Publications and source records attributed to N Buchanan.

At least 91 records · Page 5Linked to original sources
PubMed1987

Identifying patients who might benefit from free phenytoin monitoring.

Guidelines for measuring free drug concentrations in serum have become necessary due to the easy availability of these assays as a result of the introduction of commercial kits. The present study was performed to identify patients or groups of patients in whom the serum free phenytoin fraction varied from normal, such that they might benefit from measurement of serum free phenytoin. Three hundred fourteen samples submitted for routine phenytoin analysis were studied by enzyme-modified immunoassay technique (EMIT). Thirty-eight patients on phenytoin monotherapy and without other factors thought to affect protein binding of this drug had a mean (+/- SD) free phenytoin fraction of 9.8 +/- 1.8% of total concentration (mean serum albumin concentration 43.4 +/- 3.9 g/L). The free fraction was elevated by administration of comedications which are themselves highly protein bound, and in those patients who were hypoalbuminaemic (serum albumin less than 30 g/L). The groups studied were not mutually exclusive, but stepwise regression analysis showed that other factors known to affect serum albumin (e.g., age greater than 65 years, liver or renal disease, or pregnancy) did not, in themselves, produce a significant effect on free phenytoin fraction. Similarly, an elevated total serum phenytoin concentration was not a significant factor in producing an elevation in free phenytoin fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Is carbamazepine an alternative maintenance therapy for neonatal seizures?

The absorption and elimination of a hospital pharmacy preparation of carbamazepine suspension have been investigated in a group of 6 new-born and 2 older infants. The results indicate that carbamazepine is adequately absorbed from the gastrointestinal tract and that blood carbamazepine levels which are therapeutic in older children or adults are maintained with doses of 5-8 mg/kg twice daily. Elimination half-lives in this group of infants, who were each receiving other anti-epileptic drugs, varied from 7.2 to 15.2 h. Carbamazepine may provide a useful alternative to phenytoin and phenobarbitone as maintenance oral therapy in the management of neonatal seizures. Further investigation of efficacy and safety in this age group is required.

Carbamazepine↗
PubMed1986

Effect of a single oral dose of enprostil on gastric secretion and gastrin release. Studies in healthy volunteers and patients with pernicious anemia.

In healthy human volunteers, a single oral dose of enprostil (35 micrograms) inhibited basal gastric acid output by a mean of 71 percent, pentagastrin-stimulated output by 46 percent, sham-meal-stimulated output by 48 percent, and histamine-stimulated output by 16 percent. In each case, there was a reduction in both the volume and acidity of the gastric juice. Pepsin output was unchanged. Although enprostil increased the gastric pH, it did not induce basal or post-prandial hypergastrinemia. In patients with hypergastrinemia secondary to achlorhydria, enprostil lowered the basal gastrin level and reduced or abolished the post-prandial gastrin rise in a dose-related fashion. Enprostil reduces basal and stimulated gastric acid secretion and inhibits gastrin release.

Achlorhydria↗
PubMed1986

The antisecretory effects of zaltidine, a novel long-acting H2-receptor antagonist, in healthy volunteers and in subjects with a past history of duodenal ulcer.

The potency and duration of the antisecretory action of zaltidine, a novel H2-receptor antagonist, have been examined in healthy volunteers and in patients with previous duodenal ulceration. In eight healthy male volunteers single oral doses of 5 mg, 25 mg and 100 mg produced dose-related inhibition of basal and pentagastrin-stimulated acid output (M.A.O.) with an estimated ID50 of 40 mg for the latter. In eight subjects with duodenal ulceration single 100 mg and 200 mg doses produced 85% and 97% inhibition of M.A.O. at peak (3 h post-dose) and 20% and 23% inhibition at 24 h, respectively; inhibition of basal acid output was 97% at 3 h and 50% at 24 h with both doses. The long duration of action of zaltidine is ascribed to its relatively slow elimination from the plasma.

Adult↗
PubMed1985

Effects of prenatal glucocorticoids on renal maturation in newborn infants.

The effect of prenatally administered glucocorticoids on tubular reabsorption of beta 2-microglobulin and elimination half-life gentamicin have been investigated in newborn infants. beta 2-Microglobulin:creatinine ratio was significantly higher in preterm (4.43 +/- 0.88) than in full-term infants (0.89 +/- 0.42), but did not differ between infants exposed to betamethasone in utero and those who were not. Gentamicin pharmacokinetics did not differ between preterm infants who had or had not been exposed to betamethasone. It is therefore concluded that whilst prenatally administered glucocorticoids influence both pulmonary and hepatic maturation, they do not alter either renal tubular reabsorption of beta 2-microglobulin or glomerular filtration rate as estimated by gentamicin half-life.

Adult↗
PubMed1985

Strong cash flow, balance sheet, management, key to capital needs. Symposium on Healthcare Directions: the capital financing imperative.

For a full day, 10 individuals representing varied health fields and viewpoints within the healthcare industry discussed a number of topics confronting health care and predicted what the environment is likely to be in three years (see accompanying sidebars for symposium participants and purpose). This article focuses on one of the symposium topics, capital availability and financing, and the implications in a time of declining utilization.

Capital Financing↗
PubMed1984

Pharmacokinetics of cefotaxime in neonates.

The effects of gestational age on the pharmacokinetics of cefotaxime and its desacetyl metabolite during the first days of life was investigated in a group of four full-term infants and 12 preterm infants of less than 35 weeks gestation. Half of the preterm infants had received betamethasone, a drug known to facilitate hepatic microsomal drug metabolism, whilst the others had not. No significant differences in the pharmacokinetics of cefotaxime were observed between the various groups, with elimination half-life (T 1/2 beta) of cefotaxime ranging from 4.04 +/- 1.52 to 4.56 +/- 1.31 h. The desacetyl metabolite of cefotaxime was present in all post-dose serum samples, irrespective of the gestational age of the baby. Its formation was apparently unaffected by prior exposure to betamethasone. The elimination half-life of cefotaxime is significantly longer in newborn infants than in older children or adults, this increase probably results from decreased renal excretion of the drug, rather than from immaturity in its metabolism. A dose of 50 mg/kg of cefotaxime given every 12 h is appropriate for infants of less than seven days old.

Aging↗