Drugs
-
Bemiparin (bemiparin sodium; Hibor, Ivor, Zibor, Badyket) is a low molecular weight heparin (LMWH) with a lower mean molecular weight (3600 D) and a higher anti-Xa/IIa ratio (8:1) than other LMWHs. Bemiparin was effective as thromboprophylaxis in surgical patients in well controlled clinical trials. No cases of venous thromboembolism (VTE) were reported in low- to moderate-risk patients receiving prophylaxis with bemiparin 2500 anti-Xa IU/day for 7 days or unfractionated heparin (UFH) 5000 anti-Xa IU twice daily for 7 days. In high-risk patients, bemiparin 3500 anti-Xa IU/day for > or =8 days was more effective than UFH 5000 anti-Xa IU twice daily for > or =8 days in the prevention of VTE in patients undergoing total hip replacement. Postoperative bemiparin 3500 anti-Xa IU/day for 10 days was as effective as enoxaparin 4000 anti-Xa IU/day for 10 days commenced 12 hours before surgery in high-risk patients undergoing total knee replacement. As a short-term treatment for acute established deep vein thrombosis (DVT), bemiparin 5000-10 000 anti-Xa IU/day (dependent on bodyweight) for 7 or 10 days was more effective than intravenous UFH (5000 anti-Xa IU bolus followed by 30,000 or 40,000 anti-Xa IU/day for 7 days) in reducing thrombus size from baseline. Bemiparin 3500 anti-Xa IU/day was also as effective as oral warfarin (10 mg/day for the first 3 days, then adjusted to achieve an international normalised ratio between 2 and 3) for the long-term (12 weeks) treatment of DVT, although data are limited. Subcutaneous bemiparin was generally well tolerated. The most commonly reported adverse events in clinical trials were postoperative bleeding complications (similar incidence to that with UFH or enoxaparin in high-risk patients, lower incidence in low- to moderate-risk patients). ⋯ Bemiparin is a new LMWH which has shown efficacy in a small number of well controlled trials in the prevention of postoperative VTE in low- to moderate- and high-risk patients and in the treatment of established DVT. It can be initiated pre- or post-operatively, whereas recommendations for other LMWHs in Europe primarily involve preoperative initiation. Additional comparative studies would be beneficial in determining the overall place of bemiparin, particularly with respect to the relative incidence of bleeding complications. In the meantime, available data suggest that bemiparin is an effective and useful addition to the available range of LMWHs for the prevention of VTE and treatment of DVT.
-
Nesiritide (Natrecor) is a recombinant form of human B-type (brain) natriuretic peptide that has beneficial vasodilatory, natriuretic, diuretic and neurohormonal effects. The drug is administered intravenously for the management of patients with decompensated congestive heart failure (CHF). In the Vasodilation in the Management of Acute Congestive Heart Failure (VMAC) study, patients hospitalised with acute decompensated CHF who received nesiritide had significantly greater mean reductions from baseline in pulmonary capillary wedge pressure 3 hours after starting treatment than nitroglycerin or placebo recipients (-5.8 vs -3.8 and -2 mm Hg, respectively); all patients also received standard therapy (e.g. intravenous diuretics). Improvements in other haemodynamic parameters were also seen in nesiritide recipients. In addition, significantly more nesiritide than placebo recipients reported an improvement in dyspnoea after 3 hours' treatment in VMAC, whereas there was no significant difference between nitroglycerin and placebo recipients. Improvements in global clinical status, dyspnoea and fatigue were also seen with nesiritide in another active-comparator study and in a placebo-controlled study. In VMAC, there was no significant difference between nesiritide and nitroglycerin recipients in 6-month mortality. In the other active-comparator trial, 6-month mortality was significantly lower in recipients of nesiritide 0.015 micro g/kg/min than in dobutamine recipients (although mortality was not a prespecified endpoint and this result should be interpreted with caution). In this same study, the 21-day all-cause hospital readmission rate was significantly lower with nesiritide 0.015 micro g/kg/min than with dobutamine and the duration of active drug treatment was significantly shorter with nesiritide than with dobutamine. Nesiritide is generally well tolerated. In VMAC, significantly more adverse events occurred with nitroglycerin than with nesiritide. The most common adverse events reported during the first 24 hours of therapy in nesiritide and nitroglycerin recipients included general pain, abdominal pain, catheter-related pain, headache, nausea, asymptomatic and symptomatic hypotension, nonsustained ventricular tachycardia and angina pectoris. Most episodes of symptomatic hypotension resolved spontaneously or after an intravenous volume challenge of =250 ml. In addition, nesiritide does not appear to be proarrhythmic. ⋯ Short-term intravenous infusion of nesiritide is associated with haemodynamic and symptomatic improvements in patients with acutely decompensated CHF. Nesiritide may offer tolerability and practical advantages over currently used vasodilators, inodilators and inotropes in this condition; in particular, nesiritide does not appear to have proarrhythmic effects. Nesiritide also appears to be effective and well tolerated in patients receiving concomitant beta-blocker therapy and in patients with renal insufficiency. Thus, nesiritide is a suitable first-line option for the treatment of patients with acutely decompensated CHF and is a welcome addition in an area where intravenous agents are few.
-
Review Randomized Controlled Trial Clinical Trial
Imatinib mesylate: in the treatment of gastrointestinal stromal tumours.
Imatinib mesylate (imatinib) is an orally administered competitive inhibitor of the tyrosine kinases associated with the KIT protein (stem cell factor receptor), ABL protein and platelet-derived growth factor receptors. The KIT tyrosine kinase is abnormally expressed in gastrointestinal stromal tumour (GIST), a rare neoplasm for which there has been no effective systemic therapy. In a randomised, nonblind, multicentre study that evaluated imatinib 400 or 600mg once daily in 147 patients with advanced GIST, confirmed partial responses were achieved in 54% of patients overall (median duration of follow-up was 288 days). ⋯ Imatinib selectively inhibits the tyrosine kinase activity associated with KIT, which forms the rationale for evaluating its effects in GIST. Subsequent to initial evidence of the clinical efficacy of imatinib in a single patient with progressive, metastatic, CD117-positive GIST, formal studies of imatinib in this new indication were initiated. This article summarises the pharmacology, efficacy and tolerability profile of imatinib in the treatment of patients with advanced GIST.
-
Opioid treatment for postoperative or chronic pain is frequently associated with adverse effects, the most common being dose-limiting and debilitating bowel dysfunction. Postoperative ileus, although attributable to surgical procedures, is often exacerbated by opioid use during and following surgery. Postoperative ileus is marked by increased inhibitory neural input, heightened inflammatory responses, decreased propulsive movements and increased fluid absorption in the gastrointestinal tract. ⋯ Methylnaltrexone and alvimopan are recently developed opioid antagonists with activity that is restricted to peripheral receptors. Both have recently shown the ability to reverse opioid-induced bowel dysfunction without reversing analgesia or precipitating central nervous system withdrawal signs in non-surgical patients receiving opioids for chronic pain. In addition, recent clinical studies with alvimopan suggest that it may normalise bowel function without blocking opioid analgesia in abdominal laparotomy patients with opioid-related postoperative ileus.
-
Review Comparative Study
Calcineurin inhibitors in renal transplantation: what is the best option?
Recently, new calcineurin inhibitors, such as tacrolimus (FK-506) and microemulsion cyclosporin, have been approved for maintenance immunosuppression in renal transplant recipients and short-term outcomes have been accumulating. In the majority of patients, these calcineurin inhibitors have been used in combination with new immunosuppressive drugs, such as mycophenolate mofetil (MMF) or sirolimus. Under these circumstances, a comparison of cyclosporin and tacrolimus provides the answer to a very important controversial issue. ⋯ In conclusion, well tolerated and effective immunosuppression is feasible with both cyclosporin and tacrolimus. In the current immunosuppressive regimens, a calcineurin inhibitor, either tacrolimus or cyclosporin, is the essential basic standard immunosuppressant. Clinicians need to decide the best means of optimising therapy for individual patients, based on various risk factors, such as risk of rejection, i.e. sensitisation, delayed graft function and ABO-incompatibility, and some adverse events, such as hypertension, hyperlipidaemia and cosmetic changes.