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. · 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.
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Clin. Pharmacol. Ther. · Jun 1991
Randomized Controlled Trial Comparative Study Clinical TrialEffect of caffeine on ibuprofen analgesia in postoperative oral surgery pain.
Recent studies have demonstrated that caffeine acts as an analgesic adjuvant when combined with acetaminophen, aspirin, or their mixture. Our objective was to determine whether similar enhancement of analgesia could be demonstrated when caffeine is combined with ibuprofen. On a double-blind basis, a single oral dose of ibuprofen (50, 100, or 200 mg), a combination of ibuprofen, 100 mg, with caffeine, 100 mg, a combination of ibuprofen, 200 mg, with caffeine, 100 mg, or placebo was randomly assigned to 298 outpatients with postoperative pain after the surgical removal of impacted third molars. ⋯ Relative potency estimates indicated that the combination was 2.4 to 2.8 times as potent as ibuprofen alone. The combination also had a more rapid onset and longer duration of analgesic action. The analgesic adjuvancy of caffeine clearly extends to combinations with nonsteroidal anti-inflammatory drugs other than acetaminophen or aspirin.
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Clin. Pharmacol. Ther. · May 1990
Randomized Controlled Trial Comparative Study Clinical TrialMorphine and oxycodone hydrochloride in the management of cancer pain.
In a double-blind crossover study, morphine and oxycodone hydrochloride were administered to 20 patients who were experiencing severe cancer pain. The peroral doses were determined on the basis of patient-controlled intravenous titration. The assumed oral bioavailability ratios were 44% (group 1, first 10 patients) and 33% (group 2, last 10 patients) for morphine and 66% (group 1) and 50% (group 2) for oxycodone hydrochloride, respectively. ⋯ The median calculated oral/intravenous ratios giving comparable analgesia were 0.31 for morphine and 0.70 for oxycodone hydrochloride. Morphine caused more nausea than oxycodone hydrochloride and hallucinations occurred only during morphine treatment. Otherwise, there were no major differences in the side effects between these two opioids.