After receiving undergraduate teaching on the pharmaceutical industry, many medical students set out on the wards determined never to interact with 'Big Pharma' reps, refusing all the gifts they were warned about and prescribing non-proprietary drugs as soon as they get their hands on a script.

It's quite a shock on a clinical placement to attend your first grand round (a discussion of an interesting case attended by medical staff of all disciplines) and find a rep politely chatting with the consultants in front of a banner for 'the revolution in bisphosphonates'.

They never have horns and rarely try to trick you into an all-expenses paid trip to Malibu in exchange for using their drug. It's often a hospital kitchen lunch and a smartly bound copy of a trial publication.

It's vital that from the start of medical education, students must be mindful of the cost of a free lunch. The evidence – the currency we deal with in medicine – tells us that exposure counts¹, and research suggests that drug companies may spend up to twice as much on marketing as on research and development².

Ben Goldacre, a doctor and campaigner for open and honest medicine, presents countless examples of evidence of the influence of drug reps on doctors' prescribing in his book Bad Pharma¹. There are meta-analyses highlighting poor practice and horror stories of industrial secrecy and conflict of interest, but less advice on how medical students can adopt positive practice – not necessarily easy when the status quo is a weekly free meal.

There is no shortage of industrial relations guidelines for doctors, pharmaceutical representatives, pharmacists and patient groups, covering funding of research posts² down to specific figures for an acceptable meal price (£75)³.

The British Medical Association's guidance for students in particular instructs only that they should not accept meals or gifts, and should avoid meeting with pharma reps unaccompanied. Following the acknowledgement that 'as a doctor, you will work side-by-side with members of the pharmaceutical industry', students are directed to the Royal College of Physicians' Seven Principles of Public Life applied to doctors.

These are useful empirical moral standards to uphold, but young doctors might need more practicalities to fit into the working relationship between the NHS and industry.

In terms of day-to-day prescribing specifically, it's crystal clear how students should behave. Choice of drug should be based on systematic review of evidence, and since most doctors don't have time to do this for everything they prescribe, we rely on NICE to review the evidence and present clear guidance wherever possible.

Prescribing should be non-proprietary (using the generic drug name, not a brand) in most circumstances, with common exceptions being insulins and Parkinson's medications⁴. Individual trusts will make decisions about which drugs they recommend locally and which they stock, so pharmacists can be a useful resource on any queries.

With ethical and legal advice pointing students away from the pharmaceutical industry, it's natural to feel wary of any drug companies, forgoing conferences and research opportunities for fear of being incriminated by a conflict of interest.

But the NHS and pharmaceutical industries are symbiotic. The way to a prescriber's pad should be through rigorous research, not their belly, and so it's essential that doctors work with industry to carry out well-designed, thorough trials and publish their findings.

Goldacre's Bad Pharma covers issues in research too, and these issues are not going to solve themselves. Medical students can become key players by critically appraising research early in their careers, and becoming evidence-based practitioners when the time comes.

When it comes to industry interaction, the guiding principles for students must be honesty and integrity. It can be difficult to navigate the empirical advice given to students and junior doctors, especially where lack of direction can result in ambiguity.

Educate yourself on the issues at hand and grow confident in finding reliable sources of prescribing information. The pharmaceutical industry is a necessary cog in the machine of healthcare, so while it is wise to avoid the lure of a free lunch, closing yourself off to industry entirely may cause you to miss the opportunity to influence the ever-changing landscape of medicine.

The views expressed in this article are those of the member concerned, and do not necessarily reflect the views and policy of the MDU.