If one company epitomises the modern drugs industry it is Pfizer. Just a decade ago, it was regarded as an industry also-ran. But the US company has powered its way up the global ranking list to its unassailable position thanks mainly to its marketing prowess.

While some of Pfizer's research has been excellent, its success stems largely from its ability to turn drugs - often ones licensed in from its competitors - into multi-billion dollar products.

Pfizer's achievements in particular, and the importance of marketing in general, has rippled through the industry.

It is manifested in the "arms race" of escalating numbers of sales representatives, particularly in the US; the huge pre-launch marketing budgets when companies try to make as big a splash as possible; and the aggressive TV advertising campaigns with which some drugs, such as Claritin and Viagra, have been turned into household names.

Drug companies plough about 30 per cent of their revenue into sales and marketing against about 20 per cent into R&D. Some of the development budget - especially the design of clinical trials to differentiate one's medicine from those of competitors - may also be seen as marketing investment, particularly in the case of post-launch studies.

Carrie Cox, head of global pharmaceuticals at Pharmacia, a US company, has calculated that soft drink manufacturers spend proportionately more on marketing than drug companies. But the fact that she thought to make the comparison in the first place shows how central marketing has become in the modern pharmaceuticals industry.

"Marketing and sales is one of the key differentiators in a company's ability to be successful and will be even more so going forward," says David Ebsworth, head of Bayer's pharmaceuticals division.

"One of the challenges that the industry faces is to improve the effectiveness of its sales and marketing organisation."

In spite of the enormous budgets, pharmaceutical marketing skills have traditionally lagged those of other industries. That is mainly because drug companies have been separated from their ultimate customer, the patient, through strict regulations and a culture in which the physician has been king.

But as regulations are relaxed and as patients become ever more knowledgeable about their health, drug companies are having to learn marketing skills already mastered by consumer goods companies.

Many pharmaceutical companies are hiring staff from the fast-moving consumer goods sector, most celebrated being the appointment by Switzerland's Novartis of Thomas Ebeling, a former Pepsi executive, as head of its pharmaceuticals division.

Mr Ebeling has set about applying some of the lessons he learnt in the world of soft drinks - market research, consistent message, branding etc - to selling drugs. The result: Novartis's performance in the crucial US market has improved significantly.

Companies are devoting more attention to the possibilities opened by the internet and relaxed rules on television advertising to forge closer, more complex relationships with doctors, patients and other purchasers. Yet for all the undoubted change of emphasis, much has remained the same.

For now, at least, muscle still appears to be the crucial factor. "The importance of the sales rep has grown," says Ms Cox at Pharmacia. "At different points in time, it has been predicted that sales reps would become irrelevant, that they'd be replaced in some way. In fact, that hasn't proved to be the case at all."

Only a few years ago, 2,000 sales reps in the US was considered reasonable. Now salesforces of 5,000 and upwards are becoming the norm as companies add ever more divisions.

Some companies, such as Merck and Lilly, are trying to make as much noise as possible to ensure that messages about their medicines are not drowned out by the competition.

Others, notably Glaxo SmithKline, are seeking to emulate Pfizer by becoming the "marketing partner of choice" - the company others will select to help promote their potential blockbusters.

One of the reasons for seeking to shout louder is that medicines enjoy a far shorter period of market exclusivity, says Raymond Gilmartin, chairman and chief executive of Merck.

Under his leadership, Merck has drastically improved its marketing capabilities. Market exclusivity is becoming the stuff of nostalgia because, once a molecule's properties are known, scientists have become ever more adept at inventing me-too versions of the same medicine.

Merck launched Vioxx, its Cox-2 inhibitor, a new type of medicine for arthritic pain, within months of the launch of Celebrex, a rival drug that beat it to the market.

Both Merck and Pharmacia/Pfizer, which co-promote Celebrex, have spent hundreds of millions of dollars trying to outshout each other and differentiate their products. As excitement about Cox-2s has grown, both have become billion-dollar blockbusters.

Mr Ebsworth concedes the blunderbuss approach can be effective, but he believes there must be another way. "It reminds me of the western front; over the top and at them. Basically that's the level of sophistication of a lot of particularly-US based pharmaceutical companies."

He thinks the industry's message will gradually become more subtle. "Over time I'm sure that better understanding of target audience needs and the ability to better target the message will become more important."

Ms Cox says there are signs that this is already happening as companies tailor their message to different audiences, whether to managed-care organisations, specialists, general practitioners or patients.

"The role of the rep and the personal selling contact remains the pivotal foundation of marketing in the industry. But what has fundamentally changed is that you've added many more customers, so its become more complex."

With managed care organisations in the US and reimbursement agencies in Europe, reps have had to learn the language of health economics to demonstrate that their medicines provide value for money.

With specialists, such as oncologists, urologists or ophthalmologists, she says reps go through training comparable with a medical student, drastically improving the quality of dialogue between company and customer.

"The name of the game in any business is customer value and customer focus," she says. "It's something that the pharmaceutical industry has been a little bit slower in recognising than some other industries."