Prescrire international
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Prescrire international · Apr 2002
Comparative StudyCapecitabine and tegafur + uracil: new preparations. Metastatic colorectal cancer: two oral fluorouracil precursors, few advantages.
(1) The standard chemotherapy for metastatic colorectal cancer is intravenous fluorouracil combined with calcium folinate. This treatment improves the median survival time by approximately 4-6 months compared with optimal palliative care. (2) Two metabolic precursors of fluorouracil are now available in the European Union for first-line oral treatment of metastatic colorectal cancer, namely capecitabine and tegafur + uracil. According to the licensing terms, only the tegafur-uracil combination must be given with calcium folinate. (3) The evaluation files on each of these two cytotoxic agents contain data from two comparative unblinded trials versus intravenous fluorouracil + calcium folinate (Mayo Clinic protocol). ⋯ Longer postmarketing follow-up is available for the tegafur + uracil combination, which has been used in Japan for many years. (5) Patients receiving capecitabine or tegafur + uracil + calcium folinate have to take large numbers of tablets or capsules. (6) In practice, the standard treatment for metastatic colorectal cancer remains the fluorouracil + calcium folinate combination. The tegafur + uracil + calcium folinate combination is only useful for patients who prefer oral administration. Capecitabine has no documented advantage over this latter combination.
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Prescrire international · Feb 2002
7-valent pneumococcal conjugate vaccine: new preparation. Prevents rare invasive infections in infants.
(1) Infants under two years of age are the children most exposed to invasive pneumococcal infections (meningitis and bacteraemia). The estimated incidence in France is about 45 cases per year per 100,000 in the first year of life. ⋯ Some small studies of children with sickle-cell disease show adequate immunogenicity. (7) The known adverse effects of the 7-valent vaccine are acceptable, mainly comprising local reactions and fever. (8) The risk of an epidemiological shift towards serotypes not covered by the vaccine (through pharyngeal carriage and invasive infection) cannot been ruled out. In otitis media, an increase in pneumococcal infections due to serotypes not covered by the vaccine negates the benefit of vaccination. (9) In practice, considering the severity of invasive pneumococcal infections and the documented efficacy and safety of the 7-valent conjugate vaccine, vaccination is warranted for individual children under two years of age, especially those at risk, but epidemiological monitoring and pharmacovigilance must continue.
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Some published cases of difficulty with micturition and urinary retention on tramadol resemble adverse effects that are well known to occur with other opiates.