There are two main types of manufacturer's literature.

1. Promotional materials including advertisements on handouts, posters, articles in scientific journals (sometimes paid for as an advertisement), books, videos and web site promotions. They frequently tend to exaggerate the benefits of the medicines being promoted while playing down their potential harmful effects; such materials should never be used as a basic source of NF information (7, 8).

2. Documentation approved by drug regulatory authorities include the Summary of product characteristics or Product information file, package inserts and labelling information. Clinical information in these documents can sometimes be limited and outdated on indications, contraindications, dosages, adverse effects and drug interactions, especially in countries with weak drug regulatory authorities. In some countries due to financial disincentives or lack of enforcement by the regulatory authority, manufacturers may not apply for renewed approval for new indications and/or the updating of labelling and package inserts. Therefore these materials may not reflect the current, evidence-based use of the product.

However, this type of document may be a suitable source of specialized pharmaceutical information for NF monographs on aspects such as instructions for administration and reconstitution, and cautions on handling and storage.

The quality of information generated directly by the manufacturer can vary greatly from country to country and if these sources are used in the development of the NF, the information extracted from them should always be confirmed by comparing it to other independent sources.