Drugs
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Acute uppergastrointestinal bleeding in intensive care unit (ICU) patients may occur due to peptic ulcer disease, adverse drug effects, gastric tube lesions, acute renal failure, liver failure or stress-induced gastric mucosal lesions. Gastric acid hypersecretion can be observed in patients with head trauma or neurosurgical procedures. Gastric mucosal ischaemia due to hypotension and shock is the most important risk factor for stress ulcer bleeding. ⋯ The selection of drugs today depends not only on efficacy but also on possible adverse effects and on costs. In this regard, the most cost-effective drug is sucralfate. The clinical relevance of nosocomial pneumonia due to gastric bacterial overgrowth has decreased during the past decade due to several changes in the management of critically ill patients.
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Dolasetron (dolasetron mesilate) is a pseudopelletierine-derived 5-HT3 antagonist which has recently become available for clinical use. It is rapidly converted in vivo to its active major metabolite, hydrodolasetron, which appears to be largely responsible for its pharmacological activity. In clinical trials, single intravenous or oral doses of dolasetron were effective in preventing acute chemotherapy-induced nausea and vomiting (CINV). ⋯ Dolasetron and other 5-HT3 receptor antagonists have been associated with minor changes in ECG intervals, but these generally do not appear to be clinically important. Thus, available evidence suggests that dolasetron will provide an alternative to other 5-HT3 receptor antagonists for the management of CINV and PONV. Further studies are required to determine whether it offers any advantages over other agents in these settings and to determine the optimum dosage for preventing RINV.
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Review Comparative Study
Cisatracurium besilate. A review of its pharmacology and clinical potential in anaesthetic practice.
Cisatracurium besilate (besylate) is a nondepolarising neuromuscular blocking agent with an intermediate duration of action. It is the R-cis, R'-cis isomer of atracurium besilate and is approximately 3-fold more potent than the mixture of isomers that constitute the parent drug. The ED95 for cisatracurium besilate (dose required to produce 95% suppression of twitch response to nerve stimulation) in adults is 0.05 mg/kg during N2O/O2 opioid anaesthesia. ⋯ Relative to atracurium besilate, cisatracurium besilate has a lower propensity to cause histamine release is more potent but has a slightly longer onset time at equipotent doses. It also offers a more predictable recovery profile than vecuronium after prolonged use in patients in intensive care. Thus, comparative data provide some indication of the potential of cisatracurium besilate as an intermediate-duration neuromuscular blocking agent but further comparisons with other like agents are required to define precisely its relative merits.
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Complicated urinary tract infections are infections in the setting of structural or functional abnormalities of the genitourinary tract. They encompass a wide variety of clinical syndromes and anticipated outcomes. The infecting micro-organisms isolated are more varied and demonstrate a higher prevalence of antimicrobial resistance in complicated compared to uncomplicated urinary tract infections. ⋯ Antimicrobial agents are similar to those used to treat uncomplicated urinary tract infection. Certain agents, such as nitrofurantoin, should be avoided for individuals with renal failure. No specific agent or class of agents has consistently demonstrated greater therapeutic efficacy where the infecting organism is susceptible to the given agent.
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The central alpha 2 adrenoceptor agonist tizanidine is a myotonolytic agent used in the treatment of spasticity in patients with cerebral or spinal injury. Wide interpatient variability in the effective plasma concentrations of tizanidine means that the optimal dosage must be titrated over 2 to 4 weeks for each patient (dosages of 2 to 36 mg/day have been used in clinical trials). Maximum effects occur within 2 hours of administration. ⋯ In conclusion, tizanidine is an antispastic agent with similar efficacy to that of baclofen and a more favourable tolerability profile. While drowsiness is a frequently reported adverse effect with both agents, subjective muscle weakness appears to be less of a problem with tizanidine than with baclofen. Tizanidine, therefore, appears to be an attractive therapeutic alternative for patients with spasticity associated with cerebral or spinal damage.