Prescrire international
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Prescrire international · Nov 2015
Obstacles to transparency over pharmacovigilance data within the EMA.
In July and August 2014, the European Medicines Agency (EMA) organised two public consultations concerning European pharmacovigilance. These two consultations reveal a number of EMA proposals that are counterproductive to the objective of improving transparency over pharmacovigilance data. The EMA's proposals offer pharmaceutical companies an opportunity to participate in public hearings held by the European Pharmacovigilance Risk Assessment Committee (PRAC), in order to defend their drug. ⋯ The strings attached to the access that the EMA proposes to grant researchers to data contained in the centralised European pharmacovigilance database would allow the EMA to censor the publication of their findings. The EMA seems to regard pharmacovigilance data as commercially confidential information. Responding to these consultations provided an opportunity to remind the EMA that data about adverse effects are a public good, in the common interest, and that it is unacceptable to keep this information confidential.
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Prescrire international · Nov 2015
Riociguat (Adempas). Chronic thromboembolic pulmonary hypertension with markedly restricted physical activity.
When pulmonary hypertension results in marked limitation in activities of daily living (functional class III), the first-choice vasodilator is bosentan, despite its limitations. There is no proven advantage of adding another vasodilator. The adverse effects of vasodilators outweigh their uncertain efficacy in patients with only a slight limitation of physical activity (class II). ⋯ Riociguat was teratogenic in experimental animals. In practice, in the absence of a better alternative, riociguat is an option for some patients with chronic thromboembolic pulmonary hypertension that markedly restricts their activities of daily living. It has no demonstrated advantage for other patients.
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Prescrire international · Oct 2015
Naltrexone + bupropion (Mysimba). Too risky for only modest weight loss.
Weight loss and its long-term maintenance are mainly based on dietary measures and regular physical activity. There are currently no weight-loss medications with a favourable harm-benefit balance. Bupropion is chemically related to certain amphetamines, while naltrexone is an opioid receptor antagonist. ⋯ The naltrexone + bupropion combination is subject to many pharmacokinetic interactions, as well as pharmacodynamic interactions leading to additive convulsive or hypertensive effects, or undermining the action of antihypertensive drugs. A teratogenic effect of bupropion cannot be ruled out. In practice, given the limited effect of the naltrexone + bupropion combination on weight loss (a few kilograms), along with the lack of evidence supporting a persistent benefit or a decrease in the clinical complications of obesity, there is no reason to expose patients to its many potentially severe adverse effects.
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Prescrire international · Oct 2015
Hypothyroidism in adults. Levothyroxine if warranted by clinical and laboratory findings, not for simple TSH elevation.
Hypothyroidism is a common disorder due to inadequate thyroid hormone secretion. When a patient has signs and symptoms suggestive of hypothyroidism, how is it determined whether thyroid hormone replacement therapy will have a favourable harm-benefit balance? How should treatment be managed? To answer these questions, we conducted a review of the literature using the standard Prescrire methodology. The symptoms of hypothyroidism are due to slow metabolism (constipation, fatigue, sensitivity to cold, weight gain, etc.) and to polysaccharide accumulation in certain tissues, leading to hoarseness, eyelid swelling, etc. ⋯ The main challenge is to recognise transient hypothyroidism, which does not require life-long treatment. When the TSH is only slightly elevated, there is a risk of attributing non-specific symptoms to an abnormal laboratory result and prescribing unnecessary treatment. Watchful waiting is an alternative to routine levothyroxine prescription in case of TSH elevation.
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Prescrire international · Sep 2015
ReviewBevacizumab (AVASTIN) and age-related macular degeneration. Lower cost does not justify taking risks.
Intravitreal injection of ranibizumab, a VEGF inhibitor, is an option for patients with neovascular age-related macular degeneration (AMD). Because of its lower price, bevacizumab, a VEGF inhibitor closely related to ranibizumab and marketed for the treatment of various malignancies, is sometimes used off label for intravitreal injection in AMD. In 2011, the harm-benefit balance of bevacizumab in patients with AMD was uncertain. ⋯ In early 2015, there are no bevacizumab products suitable for intravitreal injection. In 2011, cases of sight-threatening infectious endophthalmitis were reported in the United States, following contamination during syringe preparation for intravitreal administration. In practice, when treatment with a VEGF inhibitor is considered for AMD, it is more prudent to choose ranibizumab, despite its currently unacceptable price.