Drugs
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Ethylene glycol, a common antifreeze, coolant and industrial solvent, is responsible for many instances of accidental and intentional poisoning annually. Following ingestion, ethylene glycol is first hepatically metabolised to glycoaldehyde by alcohol dehydrogenase. Glycoaldehyde is then oxidised to glycolic acid, glyoxylic acid and finally oxalic acid. ⋯ Like ethanol, fomepizole inhibits alcohol dehydrogenase; however it does so without producing serious adverse effects. Unlike ethanol, fomepizole is metabolised in a predictable manner, allowing for the use of a standard, validated administration regimen. Fomepizole therapy eliminates the need for the haemodialysis that is required in selected patients who are non-acidotic and have adequate renal function.
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Argatroban is a direct thrombin inhibitor synthesised to bind to the catalytic site of the thrombin molecule. It binds rapidly and reversibly to both clot-bound and soluble thrombin. ⋯ Argatroban, given to patients with heparin-induced thrombocytopenia (HIT) and heparin-induced thrombocytopenia with thrombosis (HITTS) in a large scale, nonrandomised, prospective trial, reduced a combined end-point of morbidity and mortality when compared with historical controls. Argatroban was well tolerated in clinical trials of patients with HIT and caused no increase in bleeding risk compared with historical controls.
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Parecoxib (parecoxib sodium) is an injectable pro drug of valdecoxib, which is a potent and selective inhibitor of cyclo-oxygenase-2. Intravenous (IV) or intramuscular (IM) parecoxib >20 mg has analgesic activity superior to that of placebo and similar to that of IV or IM ketorolac 30 or 60 mg well controlled trials in patients with postoperative dental pain (n = 304 to 457). In a well controlled trial (n = 202), IV parecoxib 20 or 40mg showed analgesic activity greater than that of placebo and IV morphine 4mg and similar to that of IV ketorolac 30 mg following gynaecological surgery Following orthopaedic surgery, the analgesic activity of IV parecoxib 20 or 40mg was similar to that of IV ketorolac 30 mg and superior to that of IV morphine 4 mg or placebo in well controlled trials (n = 175 and 208). ⋯ The most common adverse events irrespective of treatment (parecoxib, ketorolac or placebo) after dental surgery were nausea, alveolar osteitis, dizziness and headache. Nausea, abdominal pain, headache, abdominal fullness, dizziness, back pain, fever, hypoactive bowel sounds, vomiting, tachycardia, somnolence, abnor mal breath sounds and pruritus occurred in > or = 10% of parecoxib recipients after gynaecological surgery. Similar results were seen in placebo recipients.
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The inhaled anaesthetic sevoflurane is metabolised into two products that have the potential to produce renal injury. Fluoride ions are produced by oxidative defluorination of sevoflurane by the cytochrome P450 system in the liver. Until recently, inorganic fluoride has been thought to be the aetiological agent responsible for fluorinated anaesthetic nephrotoxicity, with a toxic concentration threshold of 50 micromol/L in serum. ⋯ Therefore, the United States Food and Drug Administration recommends the use of sevoflurane with fresh gas flow rates at least 1 L/min for exposures up to 1 hour and at least 2 L/min for exposures greater than 1 hour. We believe this is a rational, cautious approach based on available data. However, it is important to note that other countries have not recommended such limitations on the clinical use of sevoflurane and problems have not been noted.
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Chronic obstructive pulmonary disease (COPD) is a progressive disease with alveolar destruction (emphysema) and bronchiolar fibrosis (obstructive bronchitis) in variable proportions. Reducing disease progression, as assessed by forced expiratory volume in I second (FEV1) decline, health-related quality of life, exacerbation rate and mortality, is a more realistic outcome than physiological improvement. This paper reviews all the published studies of at least 100 patients followed for at least 2 years. ⋯ High dose inhaled corticosteroids have a favourable risk/benefit ratio in patients with advanced disease, particularly those with frequent exacerbations, and no benefit for those with very mild disease. It is not possible from the data to make firm recommendations for the important intermediate group where delaying progression is likely to lead to greatest benefit. I believe high dose inhaled steroids are warranted for those with intermediate severity COPD, who have frequent exacerbations or significant COPD-related symptoms.