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Biomedical subjects

M Orme

Publications and source records attributed to M Orme.

At least 55 records · Page 3Linked to original sources
PubMed1982

Labetalol in essential hypertension.

1 Labetalol is an effective agent in essential hypertension as documented in open studies and controlled studies in which its efficacy has been compared with both placebo and a variety of other anti-hypertensive drugs. 2 Labetalol given by mouth lowers blood pressure rapidly. There is no evidence of tolerance to its anti-hypertensive action. 3 Adverse effects include excessive hypotension, but only when the drug is given in large doses. Epigastric discomfort and scalp tingling have been documented especially after intravenous administration. 4 From a pharmacokinetic and pharmacodynamic point of view, labetalol can be given once daily, but postural hypotension after large (greater than 1 g) single doses may limit the usefulness of once daily regimes. Twice daily administration appears an acceptable compromise.

Adrenergic beta-Antagonists↗
PubMed1982

The effects of ampicillin on oral contraceptive steroids in women.

1 Thirteen women taking long term oral contraceptive steroids were studied while taking ampicillin (500 mg three times daily) and compared to a control cycle while not taking ampicillin. 2 There were no significant changes in the plasma concentrations of ethinyloestradiol, levonorgestrel, follicle stimulating hormone or progesterone, although lower concentrations of ethinyloestradiol were noted in two women. 3 We conclude that most patients taking oral contraceptive steroids do not need to take alternative contraceptive precautions while taking ampicillin.

Adult↗
PubMed1982

The influence of urinary pH on the disposition of indomethacin in healthy volunteers.

The influence of urinary pH on the plasma levels and renal elimination of unchanged indomethacin has been studied in seven healthy volunteers with the use of a specific and sensitive gas-liquid chromatographic method assay for indomethacin in plasma and urine. There is a wide variation in the terminal t1/2 (2.5-10.3 h) and the AUC (5264-12693 ng/ml h) of indomethacin after a standard oral dose (50 mg) under 'normal' urinary condition. Such variation is probably, in part, due to an intersubject difference in extrarenal elimination of the drug. The urinary recovery of unchanged indomethacin is highest at alkaline pH (15.7 +/- 5.3%), lowest at acidic pH (3.5 +/- 2.0%) and the 'normal' value is 7.1 +/- 1.6%. These differences are statistically significant. Despite such influence there is no apparent change in plasma levels of the drug under uncontrolled and controlled (acidic and alkaline) conditions of urinary pH. The clinical implication is that possible changes in urinary pH during long-term treatment of arthritic patients may not affect the overall kinetics of indomethacin which is extensively eliminated by the extrarenal route.

Absorption↗
PubMed1980

The interaction of phenobarbital and other anticonvulsants with oral contraceptive steroid therapy.

In a group of 5 women on long-term anticonvulsant and oral contraceptive therapy, the plasma ethynylestradiol (EE) concentration on 50 microgram EE daily was 11.1 +/- 4.5 pg/ml. These values were at the lower end of the range found in normal women in this laboratory taking 30 microgram EE daily (6-190 pg/ml). Four women have been studied prospectively for 3 months, over 1 cycle before and 2 cycles during phenobarbital 30 mg b.i.d. therapy. Significant falls in the plasma EE concentration were seen in two women (from 104.8 +/- 13.4 to 37.7 +/- 2.0 pg/ml and from 125.6 +/- 23.8 to 34.8 +/- 6.7 pg/ml p less than 0.01) and breakthrough bleeding was seen in both women. No changes in plasma concentrations of follicle stimulating hormone, progesterone, norethindrone or norgestrel were seen. There was a significant increase in the sex hormone binding globulin capacity from 100.7 +/- 5.8 to 133.3 +/- 1.2 nmoles/1 (p less than 0.05). These changes are consistent with the known microsomal enzyme inducing effect of phenobarbital.

Adolescent↗
PubMed1980

Indomethacin in rheumatoid arthritis: comparison of oral and rectal dosing.

1 Indomethacin 100 mg nightly for 1 week has been administered to 13 patients with rheumatoid arthritis by both oral and rectal routes in a double-blind, randomized, cross-over study. 2 Clinical assessments were performed at 09.00 and 14.00 h on the last 3 days of each active treatment period and compared to the results on the last 2 days of the placebo control period. 3 Indomethacin produced significant improvements in the clinical assessments at both 09.00 and 14.00 h compared to placebo but not differences were seen between the two routes of administration. 4 No significant difference was seen in the side effects experienced in the two periods. 5 The mean (+/- s.e. mean) plasma indomethacin concentration at 09.00 h in the oral period was 200.3 +/- 27.4 ng/ml, not significantly different from that in the suppository period (220.0 +/- 28.9 ng/ml). 6 Indomethacin 100 mg nightly by mouth is as effective as a 100 mg suppository and easier to administer.

Administration, Oral↗
PubMed1980

The effect of indomethacin on renal function in man.

Twenty-one patients with rheumatoid arthritis were given indomethacin 25 mg t.i.d. by mouth for 3 weeks followed by indomethacin 25 mg t.i.d. plus a 100 mg suppository at night, after a 5-day period on placebo capsules. The mean (+/- S.E.) 24-hour creatinine clearance was 57.8 +/- 5.7 ml/min in the placebo period and was not significantly altered during indomethacin therapy, 53.1 +/- 5.5 ml/min in the oral period and 56.6 +/- 6.4 ml/min in the oral plus suppository period (P greater than 0.1). In 6 volunteers, duplicate 2-hour creatinine clearances were performed after a single oral dose of 50 mg indomethacin. After placebo capsules the mean creatinine clearance was 133.7 +/- 9.5 ml/min and after 50 mg indomethacin it was 126.5 +/- 8.9 ml/min (P greater than 0.1). In 4 of the volunteers the mean creatinine clearance after 8 days on indomethacin 25 mg q.i.d. was 117.1+/- 5.3 ml/min (P greater than 0.1). Indomethacin plasma concentrations were in the usual range for the dose given. Indomethacin caused no reduction in the creatinine clearance in spite of causing significant inhibition of prostaglandin E synthesis.

Administration, Oral↗
PubMed1978

Postgraduate education in therapeutics: experience in Merseyside.

A teaching programme in therapeutics for general practitioners in Merseyside, which was led by a group of clinical pharmacologists, had as its principal aim to emphasise the importance of rational drug prescribing. The course comprised 15 sessions restricted to 25 GPs, and the topics were suggested by both the organisers and the GPs. Though each session was introduced by a clinical pharmacologist, the emphasis was an open discussion and exchange of views. This programme may serve as a pattern for other centres.

Drug Prescriptions↗
PubMed1976

Plasma levels and effects of metoprolol on blood pressure, adrenergic beta receptor blockade, and plasma renin activity in essential hypertension.

The effects of metoprolol, a selective beta adrenergic receptor antagonist, on blood pressure, beta receptor blockade (antagoinst of isoproterenol and exercise tachycardia), and plasma renin activity (PRA) have been compared with those of placebo in 16 patients with essential hypertension. The dose of metroprolol was 25 mg three times daily for 1 wk and thereafter 100 mg three times daily for 5 wk. The mean decrease in blood pressure during treatment with metoprolol was 24 +/- 3.8 (SEM)/10 +/- 2.1 mm Hg in the lying position and 23 +/- 4.4/9 +/- 3.1 mm Hg after 1 min in the standing position. At a dose of 2.9 to 5.4 mg/kg, steady-state plasma concentrations of metoprolol varied 17-fold (from 20 to 341 ng/ml) between patients and correlated with the interindividual variability in isoproterenol antagonism (r = 0.58, p less than 0.05) and decrease in exercise tachycardia (r = 0.65, p less than 0.01). By contrast, neither of these variables correlated with the dose of metoprolol in mg/kg. Metoprolol decreased PRA by 67 +/- 1.9 and 71 +/- 1.2% in the lying and standing positions, respectively. The decrease in the mean arterial blood pressure in the lying position was significantly correlated to the PRA during the placebo period (r = 0.61, p less than 0.05) but not to the plasma steady-state levels of metoprolol, the degree of beta receptor blockade, and the decrease in PRA.

Adrenergic beta-Antagonists↗
PubMed1976

Plasma concentration of phenylbutazone and its therapeutic effect-studies in patients with rheumatoid arthritis.

1 Phenylbutazone in doses of 50, 100, 200 and 300 mg/day has been given for four periods of 3 weeks to seven patients with rheumatoid arthritis. The trial was double-blind and the order of administration of doses was arranged to eliminate order and carry-over effects. 2 Before the trial and at the end of each period, the patient's responses were assessed by measurement of the duration of morning stiffness, the pain score, paracetamol tablet count, grip strength, digital joint size and articular index. 3 The plasma phenybutazone concentration was measured by gas-liquid chromatography and was also predicted by prior measurement of the phenazone half-life. 4. Compared with the pretreatment period, phenylbutazone had a significant therapeutic effect, as judged by morning stiffness, pain score and articular index, in a dose of 50 mg/day, but no statistically significant differences in effect were seen between the various doses of phenylbutazone. 5 There were no significant coorelations between the plasma concentration of phenylbutazone and any of the clinical assessments. 6 The plasma phenylbutazone concentration agreed closely with that predicted at doses of 50 and 100 mg, but at higher doses the plasma concentration was significantly lower than predicted (P less than 0.05). This may have been due to saturation of the protein binding sites at these doses.

Adult↗
PubMed1975

Pharmacokinetics of indomethacin.

Plasma concentrations of indomethacin have been studied in 5 healthy volunteers after single and multiple doses (25 mg intravenously [iv], 25, 50, and 100 mg orally, 100 mg rectally, and 25 mg three times daily [tid]. In 8 other normal subjects and in 5 patients a 50-mg oral dose of indomethacin was given and the indomethacin concentration was followed from 8 to 32 hr after dosing. All analyses were carried out using a new mass fragmentographic method. After oral and rectal doses the plasma decay of indomethacin was biphasic, and the data were interpreted according to a 2-compartment open model. The half-life of the beta-phase varied between 2.6 and 11.2 hr. The volume of distribution ranged from 0.34 to 1.57 L/kg and the plasma clearance from 0.044 to 0.109 L/kg/hr. There was no evidence of dose-dependent elimination. Indomethacin was rapidly and well absorbed after oral dosing with peak plasma concentrations within 2 hr. Comparison with the area under the curve (AUC) after iv dosing indicated complete bioavailability. The AUC after rectal dosing indicated complete bioavailability, but the rate of absorption was slower than after oral administration. Indomethacin, 25 mg three times daily, was also given for 9 days to the same normal subjects; equilibrium concentrations obtained did not differ significantly (p greater than 0.1) from those predicted from single-dose data in the 5 subjects.

Administration, Oral↗