The economic crisis may cost drugmakers as much as $10 billion in revenue next year as sales of prescription drugs in the US are expected to increase at their slowest rate on record, according to IMS Health. As a result, patients will turn to more generics, split pills and make fewer trips to the doctor, leading to a puny 1 percent increase in sales next year to $292, Bloomberg News writes.

This comes on top of the the pending loss of patent protection on $84 billion worth of products through 2012 and fewer FDA approvals of new drugs, which Bloomberg notes is the lowest level in 24 years. To counter waning US demand, IMS says pharma will have to focus on developing countries, led by India, China and Brazil, for growth.

“In many respects, 2009 will reflect the new shape of the global pharmaceutical market,” Murray Aitken, an IMS senior vp, says in a statement. Sales will be affected by “the shift in growth from developed countries to emerging ones, specialist-driven products playing a larger role, blockbuster drugs losing patent protection, and the rising influence of regulators and payers on health-care decisions.”

This most recent economic slowdown is expected to hit drugmakers harder than previous recessions because the amount of money US. patients have to pay out of pocket has increased as employers try to lower their health bills, according to Diana Conmy, corporate director for market insights at IMS.

“In the current environment, there is a higher level of cost shifting to patients than we’ve seen in the past,” Conmy tells Bloomberg “When you look at the levels of co-pays, and premiums and general coverage, there is more cost shifting to the patients, there are more difficult decisions to make when it comes to health care.”