Articles: acetaminophen.
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Twenty-three children (aged between 9 weeks and 11 yr) were given paracetamol suppositories 25 mg kg-1 every 6 h (maximum 5 days) after major surgery and serum and saliva concentrations were measured. There was a good correlation (r = 0.91, P < 0.05) between saliva and serum concentrations. A one-compartment linear model with first-order elimination and absorption and lag-time was fitted to the data (ADAPT II). ⋯ Mean (SD) time to reach 90% of the steady state concentration was 11.4 (8.6) h. Body weight, age and body surface area were well correlated (P < 0.05) with clearance and apparent volume of distribution. There was no evidence of accumulation leading to supratherapeutic concentrations during this dosing schedule for a mean of approximately 2-3 days.
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J. Pharmacol. Exp. Ther. · Oct 2000
Discovery of "self-synergistic" spinal/supraspinal antinociception produced by acetaminophen (paracetamol).
The mechanism of the analgesic action of one of the world's most widely used drugs-acetaminophen (paracetamol)-remains largely unknown more than 100 years after its original synthesis. Based on the present findings, this elusiveness appears to have resulted from experimental strategies that concentrated on a single target site or mechanism. Here we report on the use of analyses that we previously developed to investigate possible brain/spinal-cord site-site interaction in acetaminophen-induced antinociception. ⋯ E. = 9) microgram, that reverted toward additivity, ED(50) = 129 (S. E. = 23) microgram, when the opioid antagonist naloxone was given spinally (3.6 microgram = 10 nmol) or s.c. (3.6 mg/kg). These findings demonstrate for the first time that acetaminophen-induced antinociception involves a "self-synergistic" interaction between spinal and supraspinal sites and, furthermore, that the self-synergy involves an endogenous opioid pathway.
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Randomized Controlled Trial Comparative Study Clinical Trial
Double-blind randomized study of tramadol vs. paracetamol in analgesia after day-case tonsillectomy in children.
Fifty children (2-9 years) scheduled for tonsillectomy were enrolled in a double-blind randomized prospective study to compare postoperative analgesia provided with propacetamol/paracetamol (acetaminophen) or tramadol. A standard anaesthetic technique was used; each patient received sufentanil 0.25 microg kg(-1) intravenously followed with either i.v. propacetamol 30 mg kg(-1) or tramadol 3 mg kg(-1) before surgical incision. For postoperative analgesia, each child received either tramadol drops (2.5 mg kg(-1)) or paracetamol (acetaminophen) suppositories (15 mg kg(-1)), 6 and 12 h after surgery the first day and three times a day during postoperative days 2 and 3. ⋯ Rescue medication consisted of i.v. diclofenac (1 mg kg(-1)) during the first six postoperative hours and oral ibuprofen (6-9 mg kg(-1)) afterwards. Postoperative pain scores (Children's Hospital of Eastern Ontario Pain Scale) in recovery, numerical pain scale in the ward and at home, and rescue analgesic use were significantly lower in the tramadol group. No serious adverse effects were observed.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Use of a simple pain model to evaluate analgesic activity of ibuprofen versus paracetamol.
To evaluate the analgesic activity of ibuprofen against paracetamol using a simple pain model. ⋯ Sore throat pain provided a sensitive model to assess the analgesic efficacy of class I analgesics and discriminated between the analgesic efficacy of ibuprofen and paracetamol.
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Cancer Epidemiol. Biomarkers Prev. · Sep 2000
Comparative StudyA case-control study of analgesic use and ovarian cancer.
A recent case-control study raised the hypothesis that acetaminophen use 1 day or more per week for at least 6 months reduces the risk of epithelial ovarian cancer. We assessed analgesic use in relation to epithelial ovarian cancer risk using data from our case-control surveillance study of medication use and cancer. Patients were interviewed in hospitals in Baltimore, Boston, New York, and Philadelphia during 1976-1998. ⋯ The odds ratio for use of nonsteroidal anti-inflammatory drugs 4 or more days per week for at least 5 years, 0.5, was statistically significant. The present results provide only weak support for a reduction in the risk of epithelial ovarian cancer among acetaminophen users. They raise the possibility of an inverse association with long-term nonsteroidal anti-inflammatory drug use.