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Biomedical subjects

R M Pearson

Publications and source records attributed to R M Pearson.

At least 19 recordsLinked to original sources
PubMed1992

Lack of acipimox-digoxin interaction in patient volunteers.

1. A study was carried out to find out if digoxin and acipimox interact. 2. Six elderly patients on digoxin were each given acipimox 150 mg three daily for a week, after informed consent. Digoxin and acipimox plasma concentrations and urinary excretion were measured after the first dose of acipimox and after a week of treatment. 3. Data were fitted to a one-compartment oral absorption model. Areas under the plasma concentration-time curve, plasma and renal clearances, and elimination half-life were computed. 4. There was no significant difference in digoxin plasma concentrations and kinetic parameters before and after acipimox administration. Acipimox kinetics were not affected by the concomitant ingestion of digoxin. 5. The patients' clinical condition remained stable during the study. 6. Thus there was no evidence for an adverse interaction between digoxin and acipimox in human subjects under the conditions of this study.

Aged↗
PubMed1991

Concentration of metronidazole in cervical mucus and serum after single and repeated oral doses.

The disposition of metronidazole in cervical mucus and serum after single and repeated oral doses (400 mg) was investigated in six healthy female subjects. Metronidazole reached higher concentrations in serum than cervical mucus after both single and repeated oral doses. Metronidazole concentrations in both cervical mucus and serum were high enough to be trichomonicidal and bactericidal. After oral administration, metronidazole concentrations in cervical mucus are due to diffusion rather than ion trapping.

Administration, Oral↗
PubMed1991

Concentration of ibuprofen in cervical mucus.

Concentrations of an acidic drug, ibuprofen, in cervical mucus and serum have been measured by HPLC after oral administration in six healthy volunteers. After an 800 mg single dose of ibuprofen, the concentration reached in cervical mucus was less than 4% of that in serum. It is postulated that because ibuprofen is an acidic drug which is not subject to 'ion-trapping' in the acidic environment of cervical mucus, it is not concentrated in this secretion.

Administration, Oral↗
PubMed1991

Quantitation of albumin and alpha-1-acid glycoprotein in human cervical mucus.

1. Concentrations of albumin and alpha-1-acid glycoprotein (AGP) in human cervical mucus have been measured by a radial immunodiffusion technique. 2. The cervical mucus samples were obtained from women on combined oral contraceptives (Group A) and from women not taking this medication (Group B). In group A the mean level of albumin was 75.6 (range 22-198) mg l-1 and for AGP 6.5 (range 3-12) mg l-1. In group B the mean level of albumin was 72.9 (range 22-148) mg l-1 and for AGP 6.6 (range 3-14) mg l-1. 3. The levels of albumin and AGP in cervical mucus were less than 1% of the concentration in serum and were not affected by combined oral contraceptives. 4. The clinical and toxicological consequences of these observations, in terms of the disposition of drugs and other chemicals in the female genital tract, await elucidation.

Adolescent↗
PubMed1979

Biochemical and haematological changes induced by tienilic acid combined with propranolol in essential hypertension.

Sixteen patients with moderate essential hypertension completed a double-blind crossover trial with four treatment periods each of 6 weeks. They received in random order: placebo; tienilic acid 250 mg/day; propranolol 80 mg twice daily; and tienilic acid 250 mg/day combined with propranolol 80 mg twice daily. Average blood-pressure in the lying position was 22.6/13.1 kPa (169/98 mm Hg) on placebo; 21.0/12.5 (157/94) on tienilic aicd; 21.2/12.0 (159/90) on propranolol, and 18.9/11.5 (142/86) on tienilic acid combined with propranolol. The effects of tienilic acid and propranolol on blood-pressure were additive and there were no statistically significant interactions. Tienilic acid significantly reduced serum-urate from 0.33 to 0.18 mmol/l and induced hypokalaemia which was corrected by propranolol. Basophil count and haemoglobin were lower after tienilic acid treatment than they had been at the start of the study.

Adult↗
PubMed1979

The effect of metoprolol on plasma lipids.

Fifteen hypertensive patients entered a single-blind study to examine the effects of metoprolol (100 mg twice daily) on fasting plasma lipids. In 12 patients who completed the study, non-esterified fatty acid concentrations fell, but cholesterol and triglyceride levels were unchanged after 12 weeks' treatment. These results conflict with earlier reports of the effect of metoprolol on plasma triglyceride concentrations.

Adult↗
PubMed1979

Propranolol and tienilic acid in essential hypertension.

Sixteen patients with moderately severe essential hypertension completed a double-blind crossover trial with four treatment periods each lasting for six weeks. They received in random order, placebo; tienilic acid 250 mg/day; propranolol 80 mg b.d.; and tienilic acid 250 mg/day and propranolol 80 mg b.d. in combination. Mean blood pressure in the lying position was 169/98 mmHg on placebo, 157/94 mmHg on tienilic acid, 159/90 mmHg on propranolol and 142/86 mmHg on the combination of tienilic acid and propranolol. The effects of tienilic acid and propranolol on blood pressure were additive and there was no evidence of any interaction. The onset of the hypotensive effect of tienilic acid was gradual while the effect of propranolol was maximal within 2 weeks of the start of treatment. Tienilic acid produced a significant reduction in serum urate from 0.33 mmol/l to 0.18 mmol/l. The combination of tienilic acid and propranolol in the doses used in the trial was effective and acceptable in the reduction of raised blood pressure.

Adult↗
PubMed1979

Comparison of effects on cerebral blood flow of rapid reduction in systemic arterial pressure by diazoxide and labetalol in hypertensive patients: preliminary findings.

1 Diazoxide 300 mg and labetalol 150 mg were each injected intravenously on separate occasions into five patients with essentail hypertension. The reduction in BP caused by labetalol was slightly greater than that produced by diazoxide. 2 In contrast the reduction in cerebral blood flow (CBF) by labetalol was not statistically significant, whereas diazoxide gave a greater and statistically significant reduction in CBF. 3 These observations suggest that labetalol may have an advantage over diazoxide for the rapid reduction in BP.

Blood Pressure↗
PubMed1978

Does cyclophosphamide induce bladder cancer?

An increasing incidence of bladder neoplasms temporally associated with chemotherapy, usually cyclophosphamide, is being reported. These secondary primary bladder malignancies are characteristically found in two groups of patients: those with lymphoproliferative or myeloproliferative tumors, and those with immunosuppression after organ transplantation. A case of adenocarcinoma of the bladder associated with malignant lymphoma is reported, and the known cases of second primary bladder malignancies after cyclophosphamide therapy as reported in the literature are reviewed. Studies relating to the enhanced occurrence of second primary cancers in lymphoproliferative disorders are presented. The recognized urologic toxicities of cyclophosphamide, including cytopathologic changes in animals and humans, are discussed. The observed association between immunosuppression and second primary malignancies is explored, as supported by studies on congenital immunodeficiency in humans, viral oncogenesis in experimental animals, and neoplasia after organ transplantation. Possible mechanisms of carcinogenesis associated with cyclophosphamide are reviewed, including suppression of humoral and cell-mediated immune defense mechanisms, direct carcinogenesis, or cocarcinogenesis. A plea is made for the orderly reporting and careful documentation of bladder tumors in patients receiving cyclophosphamide. It is suggested that prospective studies in these patients and in patients receiving cyclophosphamide for nonmalignant disorders would be of value in assessing the culpability of cyclophosphamide as a carcinogen.

Abdominal Neoplasms↗
PubMed1978

Intravenous labetalol in hypertensive patients given by fast and slow injection.

1 Labetalol reduces blood pressure when given by fast or slow intravenous injection. 2 The extent of the reduction in arterial pressure is independent of the rate of injection but the rate of fall of blood pressure can be controlled by varying the rate of injection. There is little effect on heart rate. 3 These observations suggest that labetalol possesses important advantages over other vasodilator hypotensive drugs in current use.

Adult↗
PubMed1978

Dimensional stability of lathe cut C.A.B. lenses.

Measurements of the back central optical radius in the course of 336 hours of hydration of lathe cut corneal lenses disclosed changes in curvature which were more rapid and of greater magnitude than those previously reported for poly (methyl methacrylate) lenses.

Absorption↗
PubMed1977

Drug interactions.

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Drug Interactions↗
PubMed1977

Effect of oxprenolol on stage-fright in musicians.

The effect of 40 mg oxprenolol on stage-fright was assessed in 24 musicians in a double-blind crossover trial. Musical performance judged by two professional assessors was found to improve. Greatest improvement was seen on the first performance and in those most affected by nervousness.

Administration, Oral↗