Clin Pharmacokinet
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Dexketoprofen trometamol is a water-soluble salt of the dextrorotatory enantiomer of the nonsteroidal anti-inflammatory drug (NSAID) ketoprofen. Racemic ketoprofen is used as an analgesic and an anti-inflammatory agent, and is one of the most potent in vitro inhibitors of prostaglandin synthesis. This effect is due to the (S)-(+)-enantiomer (dexketoprofen), while the (R)-(-)-enantiomer is devoid of such activity. ⋯ A plateau in the analgesic activity of dexketoprofen trometamol at the 25mg dose is suggested. The time to onset of pain relief appeared to be shorter in patients treated with dexketoprofen trometamol. The drug was well tolerated.
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Meropenem is a well established carbapenem antibacterial with a wide spectrum of activity against Gram-positive and Gram-negative bacteria, including beta-lactamase producers and Pseudomonas aeruginosa. Because of its clinical and bacteriological efficacy, meropenem is an important antimicrobial drug in the treatment of serious infections in adults and in children. Meropenem is predominately excreted unchanged in the urine, and thus dosage adjustments are necessary in patients with renal insufficiency and those undergoing intermittent haemodialysis (IHD) or various forms of continuous renal replacement therapy (CRRT), such as continuous venovenous haemodialysis, continuous venovenous haemodiafiltration (CVVHDF), continuous venovenous haemofiltration (CVVHF) or continuous ambulatory peritoneal dialysis (CAPD). ⋯ Such differences are not negligible and demonstrate the great influence of the treatment modality on the elimination of the drug during renal replacement therapy. Thus, physicians run the risk of underdosing with this antimicrobial drug because of the quite different recommendations in the literature. Because of the excellent tolerability profile of meropenem, such underadministration should be avoided.
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Obesity is a worldwide problem, with major health, social and economic implications. The adaptation of drug dosages to obese patients is a subject of concern, particularly for drugs with a narrow therapeutic index. The main factors that affect the tissue distribution of drugs are body composition, regional blood flow and the affinity of the drug for plasma proteins and/or tissue components. ⋯ Adjustment of the maintenance dosage depends on the observed modifications in clearance. Our present knowledge of the influence of obesity on drug pharmacokinetics is limited. Drugs with a small therapeutic index should be used prudently and the dosage adjusted with the help of drug plasma concentrations.
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Drug delivery by target-controlled infusion (TCI) allows automatic adjustments of the infusion rate of a drug to maintain a desired target concentration. Since drug effect is more closely related to blood concentration than to infusion rate, drug delivery via TCI is capable of creating stable blood concentrations of intravenous anaesthetics and analgesics. In this article the concept and history of TCI are described. ⋯ The use of TCI for postoperative analgesia is still experimental, but TCI can, in part, overcome the disadvantages associated with continuous infusions and patient-controlled analgesia regimens in the postoperative period. Although TCI is capable of creating stable blood concentrations, when the target concentration is changed the resulting effect correlates better with a theoretical effect site concentration. The efficacy of TCI systems that can perform effect-site steering are still to be explored.
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The administration of osmotic agents is one of the principal strategies to lower elevated intracranial pressure (ICP) and to increase cerebral perfusion pressure. Of the 3 osmotic agents frequently used (mannitol, glycerol and sorbitol), each has characteristic advantages and disadvantages. In addition to renal filtration, sorbitol [elimination half-life (t1/2beta) approximately 1h] and glycerol (t1/2beta 0.2 to 1h) are metabolised, mainly by the liver. ⋯ The ability of mannitol, glycerol and sorbitol to lower elevated ICP has been extensively documented. However, whether the use of osmotic agents, particularly with repeated application, improves outcome remains unproven. Therefore, these agents should only be used to treat manifest elevations of ICP, not for prophylaxis of brain oedema.