Prescrire international
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Prescrire international · Oct 2009
Renal colic in adults: NSAIDs and morphine are effective for pain relief.
(1) Renal colic is an acute syndrome involving unilateral flank pain, linked to an obstruction in the upper urinary tract. The pain is often intense. After having considered other diagnoses and checked for signs of complication (fever, oligoanuria), the first step is to control the pain; (2) Which non-invasive treatments have a positive risk-benefit balance in relieving this type of pain? To answer this question, we reviewed the available evidence, based on the standard Prescrire methodology; (3) According to a meta-analysis of 20 trials, nonsteroidal antiinflammatory drugs (NSAIDs) and strong opioid analgesics have comparable efficacy. ⋯ Morphine is given intravenously; subcutaneous administration is an alternative although it has not been evaluated in renal colic; (4) In clinical trials, NSAIDs were associated with fewer adverse effects than opioids, which cause vomiting in about 20% of patients (versus about 6% with an NSAID); (5) NSAIDs expose patients to a risk of functional renal impairment, especially in patients with heart failure, renal artery stenosis, dehydration, renal impairment or ongoing treatment with a nephrotoxic drug, and the very elderly. NSAIDs should never be used during pregnancy; (6) According to one trial in 130 patients, the analgesic effect of the morphine and NSAID combination was greater than either agent used alone, in about 10% of patients; (7) Paracetamol has not been evaluated in comparative trials of renal colic, even for moderate pain; (8) Scopolamine is the only antispasmodic to have been evaluated in a comparative trial. Adding scopolamine to morphine did not seem to provide additional efficacy; (9) Other drugs, which have not been adequately tested as of early 2009, have no documented benefit in the treatment of the pain associated with renal colic; tamsulosin, nifedipine, desmopressin; (10) Among the non-drug measures tested, local active warming, taking care to avoid burns, was effective against pain according to one trial; pain was reduced by at least 50% using a device delivering 42 degrees C to the abdomen or lower back; (11) In pregnant women, morphine carries a lower risk of adverse effects than NSAIDs; (12) In practice, the treatment of renal colic is mainly based on taking an NSAID, or morphine when the NSAID does not adequately control the pain or when it is better to avoid using NSAIDs.
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Prescrire international · Aug 2009
Rivaroxaban: new drug. After hip or knee replacement surgery: LMWH is safer.
(1) The standard anticoagulant therapy for prevention of thrombosis after hip or knee replacement surgery is subcutaneous injection of a low-molecular-weight heparin, such as enoxaparin; (2) Rivaroxaban is an oral factor-Xa inhibitor anticoagulant approved for use in these indications in the European Union; (3) Four double-blind controlled trials in more than 12 000 patients undergoing hip or knee replacement surgery failed to show that rivaroxaban was any more effective than enoxaparin on relevant clinical outcomes; there was no reduction in mortality, nor in the incidence of pulmonary embolism and symptomatic deep venous thrombosis; (4) In the selected populations enrolled in these trials, the bleeding risk was similar in the rivaroxaban and enoxaparin groups. However, it is possible that very underweight or overweight patients have an increased bleeding risk with rivaroxaban; (5) More information is needed on the nephrotoxicity of rivaroxaban, and a risk of mitochondrial toxicity cannot be ruled out. ⋯ However, it seems best to monitor renal function. It should also be noted that there is no effective antidote if severe bleeding occurs; (8) In practice, for frail elderly patients, who are often polymedicated, it seems more prudent to continue using low-molecular-weight heparin, a drug with which we have more experience.