Clinical pharmacology and therapeutics
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Clin. Pharmacol. Ther. · Jun 1992
Randomized Controlled Trial Clinical TrialPharmacokinetic-pharmacodynamic modeling of the central nervous system effects of midazolam and its main metabolite alpha-hydroxymidazolam in healthy volunteers.
The pharmacodynamics of midazolam and its main metabolite alpha-hydroxymidazolam were characterized in individual subjects by use of saccadic eye movement and electroencephalographic (EEG) effect measurements. Eight healthy volunteers received 0.1 mg/kg midazolam intravenously in 15 minutes, 0.15 mg/kg alpha-hydroxymidazolam intravenously in 15 minutes, 7.5 mg midazolam orally and placebo in a randomized, double-blind, four-way crossover experiment. Plasma concentrations of midazolam, alpha-hydroxymidazolam and 4-hydroxymidazolam were measured by gas chromatography. ⋯ The maximum effect values were similar for both compounds. The effects observed after oral administration of midazolam could not be predicted accurately by an additive and competitive interaction model. It seems that alpha-hydroxymidazolam is highly potent with respect to the measured effects and contributes significantly to those effects of midazolam after oral administration.
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Clin. Pharmacol. Ther. · Jun 1992
Randomized Controlled Trial Comparative Study Clinical TrialAnalgesic oral efficacy of tramadol hydrochloride in postoperative pain.
Tramadol hydrochloride is a synthetic opiate agonist with a plasma elimination half-life of 5 to 6 hours and peak plasma levels at about 1 1/2 hours. It derives its activity from attachment to the mu-receptor and blockage of norepinephrine reuptake. The purpose of this single-dose, double-blind, placebo-controlled study was to determine the analgesic effectiveness of an oral administration of two dose levels of tramadol hydrochloride (75 or 150 mg) compared with the combination of 650 mg acetaminophen plus 100 mg propoxyphene napsylate in 161 patients with severe postoperative pain after cesarean section. ⋯ The 150 mg dose of tramadol was significantly more effective than the acetaminophen-propoxyphene combination from hour 2 through hour 6 for the sum of pain intensity differences and total pain relief scores, as well as for the global rating of the medication. Tramadol hydrochloride at both dose levels is an effective analgesic agent and at 150 mg is statistically superior to the acetaminophen-propoxyphene combination. No serious adverse effects were observed; however, dizziness was more frequently reported with 150 mg tramadol.
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Clin. Pharmacol. Ther. · Apr 1992
Randomized Controlled Trial Comparative Study Clinical TrialDiuretic efficiency of furosemide during continuous administration versus bolus injection in healthy volunteers.
Furosemide delivery rate in the nephron has been reported to be one of the major determinants of diuretic response. In a randomized, crossover double-blind study in eight healthy volunteers, we tested this hypothesis by comparing continuous intravenous infusion of furosemide (infusion rate, 4 mg/hr) during 8 hours after administration of an intravenous loading dose of 8 mg (total dose, 40 mg) with an intravenous bolus injection of 40 mg furosemide. ⋯ Mean total urinary volume (Vur), sodium (UNa), potassium, and chloride excretion after 8 and 24 hours were significantly greater after treatment with continuous furosemide infusion when compared with bolus injection, whereas total urinary furosemide excretion showed no differences (Vur bolus versus Vur infusion, 5270 versus 6770 ml/8 hours; UNa bolus versus UNa infusion, 314 versus 430 mmol/8 hours; both p less than 0.001). These findings strongly support the concept of the furosemide delivery rate into the nephron as a determinant of diuretic efficiency.
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Clin. Pharmacol. Ther. · Sep 1991
Randomized Controlled Trial Clinical TrialHeadache pain model for assessing and comparing the efficacy of over-the-counter analgesic agents.
To refine the assessment of over-the-counter analgesic agents in the treatment of muscle-contraction headache, we designed a single-dose model with attention to specific methodologic features and two relevant assessments--the percentage of subjects who achieve complete relief and the time until pain is no longer experienced. Subjects were randomly assigned to receive a single dose of 1000 mg acetaminophen, 1000 mg aspirin with 64 mg caffeine, or placebo. ⋯ The aspirin-caffeine combination was rated higher than acetaminophen on all summary measurements, particularly SPID (p less than 0.05), with significantly more patients obtaining complete relief with aspirin-caffeine (p less than 0.01) than with acetaminophen. We conclude that this headache pain model can be used to demonstrate the efficacy of over-the-counter analgesic agents and to assess their relative efficacy.