14.5.1  Sources of information on adverse effects of drugs

In addition to the usual sources of evidence, described in Chapter 6, review authors who are planning an exhaustive search for adverse effects of a drug may wish to consider checking the following sources:

 

Review authors can also apply (usually on payment of a fee) to the WHO Uppsala Monitoring Centre (UMC; www.who-umc.org) for special searches of their spontaneous reporting database (Vigibase); this was for example done for a Cochrane review on melatonin (Herxheimer 2002). However, the rank order of the most common adverse effects reported for one particular drug in the UMC database was found to differ from the data derived from a meta-analysis of double-blind, randomized trials (Loke 2004): the UMC data on amiodarone showed thyroid problems to have the highest frequency, with skin reactions coming second, whereas the meta-analysis showed heart problems to be most common, followed by thyroid disorders.

 

Primary surveillance data (in the form of spontaneous case reports) are also freely available via the web sites of the regulatory authorities in Canada, USA, UK, and The Netherlands. However, the format of the information varies considerably, and interpretation and analysis of these databases require specialist skills (see also Section 14.6.3).