Drugs
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Oseltamivir is the oral prodrug of GS4071, a selective inhibitor of influenza A and B viral neuraminidase. After absorption from the gastrointestinal tract oseltamivir is efficiently converted to GS4071, which is maintained at high and sustained concentrations in plasma. Based on studies in rats and ferrets, GS4071 appears to be effectively distributed to all tissues, including major sites of infection in the upper and lower respiratory tracts. ⋯ All known GS4071 resistant genotypes are growth disadvantaged and display significantly reduced infectivity in animals. Oseltamivir was well tolerated in human volunteers and patients in clinical trials. Treatment-related adverse events (primarily gastrointestinal) were mild and transient in nature.
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The concept of balanced analgesia was introduced to improve analgesic efficacy and reduce adverse effects. A large amount of clinical data has documented improved analgesia by combining different analgesics, but data on reducing adverse effects are inconclusive. Balanced analgesia should be used whenever possible, and future studies should be directed to define optimal combination regimens in individual surgical procedures.
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Rapacuronium bromide (rapacuronium) is an aminosteroid, nondepolarising neuromuscular blocking agent (NMBA). At the recommended dose for endotracheal intubation (1.5 mg/kg), an intravenous bolus of rapacuronium has a rapid onset (approximately 1.2 to 1.8 minutes) and short duration of action (10.2 to 16.5 minutes) in adults undergoing elective surgery. Rapacuronium 1.5 mg/kg produced clinically acceptable intubating conditions in 68 to 89% of these patients at about 1 minute after administration. The onset, extent and duration of action and clinical efficacy of an intubating dose of rapacuronium appeared to be similar in the general adult population, adult patients with renal or hepatic dysfunction, patients undergoing Caesarean section, and elderly, paediatric or obese adult patients. Onset time with rapacuronium 1.3 to 2.5 mg/kg (0.9 to 1.8 minutes) was similar to or slower than that with a 1 mg/kg dose of the depolarising NMBA suxamethonium chloride (0.8 to 1.2 minutes). Intubating conditions were clinically acceptable about I minute after administration in 86 to 100% of patients with rapacuronium 1.3 to 2.5 mg/kg compared with in 88 to 97% of patients with suxamethonium chloride 1 or 1.5 mg/kg. Spontaneous recovery was slower with rapacuronium than with suxamethonium chloride, but neostigmine 0.04 or 0.05 mg/kg administered 2 or 5 minutes after rapacuronium 1.3 or 1.5 mg/kg accelerated recovery. In the few available comparative clinical trials, rapacuronium 1.5 mg/kg appeared to have a more rapid onset of action than the nondepolarising NMBAs mivacurium chloride 0.25 mg/kg, rocuronium bromide 0.45 or 0.6 mg/kg or vecuronium bromide 0.07 mg/kg, and a shorter duration of action than rocuronium bromide 0.45 or 0.6 mg/kg or vecuronium bromide 0.07 mg/kg. Additional boluses (< or =3) of rapacuronium 0.5 or 0.55 mg/kg after an intubating bolus of 1.5 mg/kg provided continued skeletal muscle relaxation during short surgical procedures in adult patients. However, these patients may recover more slowly than those who receive a single bolus of the drug. Bronchospasm was the most common treatment-related adverse event with rapacuronium 0.3 to 3 mg/kg (3.4% of adult patients). Tachycardia, injection site reaction and hypotension were also reported in small proportions of patients (1.6, 1.1 and 0.9%). The overall incidence of drug-related adverse events was similar with rapacuronium 1.5 or 2.5 mg/kg or suxamethonium chloride 1 mg/kg (8 vs. 6%) but bronchospasm, tachycardia and injection site reaction tended to occur more often with rapacuronium. ⋯ At the recommended dose of 1.5 mg/kg, the nondepolarising NMBA rapacuronium has a rapid onset and short duration of action. It may provide a nondepolarising alternative to suxamethonium chloride for endotracheal intubation. Rapacuronium may be preferred over rocuronium bromide, vecuronium bromide or mivacurium chloride in this indication.