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T O Brophy

Publications and source records attributed to T O Brophy.

5 recordsLinked to original sources
PubMed1984

Pharmacokinetics of midazolam in the aged.

The pharmacokinetics of midazolam, an imidazo-benzodiazepine derivative, have been studied in 13 subjects over the age of 60 years who received the drug intravenously (0.07 mg kg-1) as an induction agent for endoscopy. Two to three days later, 6 of these subjects received 5 mg of midazolam intramuscularly, and another 6 of the subjects received 10 mg of the drug orally. The plasma concentration-time curves were again studied pharmacokinetically. After intravenous dosing, the mean (+/- SD) elimination half-life (2.14 +/- 1.24 h) showed a statistically significant trend to increase with age in the subjects older than 60 years. While the mean (+/- SD) clearance value (0.30 +/- 0.19 l kg-1h-1) tended to fall with age in the elderly subjects, this trend was not statistically significant. Apparent volume of distribution did not appear to be related to advancing age beyond 60 years, and this parameter (mean +/- SD) did not differ to a statistically significant extent between the aged subjects (0.77 +/- 0.47 l kg-1) and the young subjects studied previously (1.09 +/- 0.58 l kg-1). Atropine premedication did not appear to alter the dispositional parameters of the intravenously administered drug. Intramuscularly administered midazolam was absorbed rapidly. Bioavailability appeared incomplete (F = 0.59 +/- 0.15, mean +/- SD), possibly due to saturable elimination of the drug at the higher plasma levels which were obtained after intravenous midazolam. Oral bioavailability, relative to intravenous, was 0.34 +/- 0.17, (mean +/- SD), with an appreciable but variable lag time (0.74 +/- 0.40 h, mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1984

Midazolam for upper gastrointestinal endoscopy.

A water-soluble benzodiazepine, midazolam, was used in 400 patients undergoing upper gastrointestinal endoscopy, alone or in combination with pentazocine and compared with 68 patients given diazepam (Valium). In the last 200 patients the endoscopist used midazolam without the presence of an anaesthetist. The absence of injection pain was the most notable feature of midazolam. The degree of co-operation was similar in all groups but the operating conditions were significantly better when midazolam was combined with pentazocine. There was no significant difference in recovery times between the groups as assessed by the pegboard test. Midazolam is an acceptable alternative to diazepam for upper gastrointestinal endoscopy.

Adult↗
PubMed1981

The pharmacokinetics of midazolam in man.

Midazolam, a new water-soluble benzodiazepine, was administered as: i) 5 mg intravenously, ii) a 10-mg oral solution and iii) a 10-mg oral tablet, to six volunteers whose informed consent had been obtained. Midazolam plasma concentrations were measured using an electron-capture gas-liquid chromatographic assay. After 5-mg intravenous midazolam, subjects fell asleep within 1-2 min and continued to sleep for an average of 1.33 h. After oral midazolam intake (solution or tablets), drowsiness appeared after a average of 0.38 h (range 0.25-0.55 h) and sleep continued for an average of 1.17 h. The time to reach peak plasma midazolam concentration after the 10-mg solution dose (0.37 +/- 0.45 h) did not differ significantly ('t' = 2.04, df = 10, p greater than 0.05) from the time to reach peak plasma midazolam level after the 10-mg tablet dose (0.74 +/- 0.45 h). The terminal half-life, (t 1/2), of midazolam in plasma was 1.77 +/- 0.83 h and there was no significant difference between the mean terminal half-life values obtained for the three midazolam formulations. The mean total clearance (Cl), of midazolam after 5-mg intravenous administration was 0.383 +/- 0.0941 . kg-1 . h-1. The first pass effect, F, determined experimentally (0.36 +/- 0.09) indicated the substantial first pass metabolism of midazolam. The percentage of the midazolam dose excreted unchanged in urine in four subjects during the 0-8-h urine collection interval was very small (0.011%-0.028%).

Adult↗