Even with $20.6 billion in 2004 estimated prescription sales, pain management remains one of the most widely researched yet
undertreated therapeutic areas. That leaves plenty of room for growth, and industry experts predict that revenue from pain-management
therapeutics will reach almost $29.8 billion by 2008.
Much of that growth will be fueled by an aging global population—suffering from arthritis, cancer, diabetic neuropathy, and
postoperative pain. But those patients—and, in fact, most patients—will receive more palliative care than in the past because
of society's changing attitude toward pain management.
"In the old school of thinking, patients were hesitant to ask for more analgesics," says Carol Ammon, CEO of Endo Pharmaceuticals,
a specialty pharma with a focus on pain products. "Patients were socialized to accept a certain amount of pain. I think a
lot of that has gone out the window now. Patients realize that they can appropriately have their pain treated and that they
are not bad patients for asking to have it treated."
The biggest growth potential is in the United States, which had sales of $12.3 billion in 2003. That figure should balloon
to an estimated $21.8 billion in 2008. Leading players—including Pfizer, Purdue, Johnson & Johnson, Merck, and Novartis—account
for approximately 60 percent of the US pain-management market. Yet because there are still unmet needs in pain management,
there is room for many other companies, such as Abbott Labs, Durect, Eli Lilly, Endo, and Forest Labs, to gain market share.
Global Market Growth, Global Market Share
Defined and Indicated
The International Association for the Study of Pain (IASP) defines pain as "an unpleasant sensory and emotional experience
in association with actual or potential tissue damage, or described in terms of such damage." For patients, it's just a big
hurt, but for doctors and pharma companies seeking FDA indications, pain is typically categorized by duration: acute (postoperative
pain) or chronic (low-back pain). Chronic pain is defined as pain that lasts more than six months, and acute pain is a condition
experienced for less than six months.
Another category, neuropathic pain, is usually chronic and is caused by lesions in the peripheral or central nervous system.
Various medical conditions and external factors, including diabetes, herpes zoster (shingles), cancer, exposure to toxic substances
(including chemotherapy), alcoholism, stroke, HIV, and multiple sclerosis can all lead to neuropathic pain.
Breakthrough pain refers to intermittent flares experienced by patients who are already on a fixed, around-the-clock pain
therapy regimen. An episode can last anywhere from just a few seconds to several hours and can be triggered by a specific
activity (coughing or moving) or may start unexpectedly and for no reason.
Available therapeutics for pain can be classified in three categories: nonopioids, opioids, and adjuvants. The nonopioids
include nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (Tylenol). NSAIDs constitute the majority of this
category; they range from traditional, over-the-counter pain relievers (including aspirin, ibuprofen, and naproxen) to newer,
prescription COX-2 inhibitors (including celecoxib, rofecoxib, and valdecoxib).
NSAIDs act by inhibiting the conversion of arachindonic acid to prostaglandin, a substance produced by the body that plays
a role in inflammation and pain. Although traditional NSAIDs are considered relatively safe, COX-2 inhibitors have fallen
under increased scrutiny following Merck's voluntary withdrawal of Vioxx (rofecoxib), because of research showing increased
risks of heart attacks and strokes.