Tamiflu (oseltamivir) disminuye
los síntomas de la gripe medio día pero no reduce los ingresos
hospitalarios ni las complicaciones graves.
A nadie le gusta que le engañen. Un
grupo de médicos de familia denunciamos hace 4 años que nos estaban engañando con la campaña de pánico que se desató con la
gripe A. Ahora nos enteramos de que alguien gano mucho dinero vendiendo humo. El medicamento Tamiflu que se empleó contra la gripe no vale para nada. Miles de millones de euros de los contribuyentes se tiraron a la basura. Ayer se publicaron los
resultados de la colaboración Cochane y el BMJ donde se pone en evidencia la ineficacia del fármaco.
¿Por qué pasó esto?
Porque el laboratorio no publicó todos los ensayos clínicos que se hicieron con el fármaco. Solo publicaron los resultados positivos.
¿Cómo se puede evitar que esto pase de nuevo?
La
iniciativa Alltrials propone que se hagan públicos los resultados de TODOS los ensayos clínicos que se hagan con fármacos para evitar errores y sesgos. La transparencia es la mejor herramienta de calidad posible.
Más información en:
The Guardian
No gracias
BMJ
2014;
348
doi: http://dx.doi.org/10.1136/bmj.g2545
(Published 10 April 2014)
Cite this as:
BMJ
2014;348:g2545
Abstract
Objective
To describe the potential benefits and harms of oseltamivir by
reviewing all clinical study reports (or similar document when no
clinical study report exists) of randomised placebo controlled trials
and regulatory comments (“regulatory information”).
Design Systematic review of regulatory information.
Data sources Clinical study reports, trial registries, electronic databases, regulatory archives, and correspondence with manufacturers.
Eligibility criteria for selecting studies Randomised placebo controlled trials on adults and children who had confirmed or suspected exposure to natural influenza.
Main outcome measures
Time to first alleviation of symptoms, influenza outcomes,
complications, admissions to hospital, and adverse events in the
intention to treat population.
Results
From the European Medicines Agency and Roche, we obtained clinical study
reports for 83 trials. We included 23 trials in stage 1 (reliability
and completeness screen) and 20 in stage 2 (formal analysis). In
treatment trials on adults, oseltamivir reduced the time to first
alleviation of symptoms by 16.8 hours (95% confidence interval 8.4 to
25.1 hours, P<0 .001="" class="goog-spellcheck-word" span="" style="background: none repeat scroll 0% 0% yellow;">There
was no effect in children with asthma,
but there was an effect in otherwise healthy children (mean difference
29 hours, 95% confidence interval 12 to 47 hours, P=0.001). In treatment
trials there was no difference in admissions to hospital in adults
(risk difference 0.15%, 95% confidence interval −0.91% to 0.78%, P=0.84)
and sparse data in children and for prophylaxis. In adult treatment
trials, oseltamivir reduced investigator mediated unverified pneumonia
(risk difference 1.00%, 0.22% to 1.49%; number needed to treat to
benefit (NNTB) 100, 95% confidence interval 67 to 451). The effect was
not statistically significant in the five trials that used a more
detailed diagnostic form for “pneumonia,” and no clinical study reports
reported laboratory or diagnostic confirmation of “pneumonia.” The
effect on unverified pneumonia in children and for prophylaxis was not
significant. There was no significant reduction in risk of unverified
bronchitis, otitis media, sinusitis, or any complication classified as
serious or that led to study withdrawal. 14 of 20 trials prompted
participants to self report all secondary illnesses to an investigator.
Oseltamivir in the treatment of adults increased the risk of nausea
(risk difference 3.66%, 0.90% to 7.39%; number needed to treat to harm
(NNTH) 28, 95% confidence interval 14 to 112) and vomiting (4.56%, 2.39%
to 7.58%; 22, 14 to 42). In treatment of children, oseltamivir induced
vomiting (5.34%, 1.75% to 10.29%; 19, 10 to 57). In prophylaxis trials,
oseltamivir reduced symptomatic influenza in participants by 55% (3.05%,
1.83% to 3.88%; NNTB 33, 26 to 55) and households (13.6%, 9.52% to
15.47%; NNTB 7, 6 to 11) based on one study, but there was no
significant effect on asymptomatic influenza and no evidence of a
reduction in transmission. In prophylaxis studies, oseltamivir increased
the risk of psychiatric adverse events during the combined
“on-treatment” and “off-treatment” periods (risk difference 1.06%, 0.07%
to 2.76%; NNTH 94, 36 to 1538) and there was a dose-response effect on
psychiatric events in two “pivotal” treatment trials of oseltamivir, at
75 mg (standard dose) and 150 mg (high dose) twice daily (P=0.038). In
prophylaxis studies, oseltamivir increased the risk of headaches
on-treatment (risk difference 3.15%, 0.88% to 5.78%; NNTH 32, 18 to
115), renal events with treatment (0.67%, −0.01% to 2.93%), and nausea
while receiving treatment (4.15%, 0.86% to 9.51%; NNTH 25, 11 to 116).
Conclusions
In prophylactic studies oseltamivir reduces the proportion of
symptomatic influenza. In treatment studies it also modestly reduces the
time to first alleviation of symptoms, but it causes nausea and
vomiting and increases the risk of headaches and renal and psychiatric
syndromes. The evidence of clinically significant effects on
complications and viral transmission is limited because of rarity of
such events and problems with study design. The trade-off between
benefits and harms should be borne in mind when making decisions to use
oseltamivir for treatment, prophylaxis, or stockpiling.
