Pain Program

Clinical Pain

Pain results from sensory nerve stimulation often associated with actual or potential tissue damage. Specific nerve fibers carry the pain signal across the nervous system to the brain, where it is recognized as pain.  Pain is generally characterized on two dimensions, intensity and duration.

Pain intensity is typically expressed as mild, moderate or severe.  Mild pain results from relatively common conditions such as headaches, sprains or strains. Moderate pain results from conditions such as surgery, severe strains or sprains. Severe pain results from serious underlying illnesses such as cancer, AIDS, osteoarthritis, lower back pain and diabetic neuropathy.

Pain duration is expressed as acute or chronic.  Acute pain often subsides in a short period of time and is typically associated with tissue injury such as surgery, a cut, a joint dislocation, or pressure on a nerve. Chronic pain persists for long periods of time and may involve underlying changes in the nervous system producing unusual sensitivity to touch, shooting pains, aching and other often disabling pain symptoms.

Chronic pain, affecting millions worldwide, is broken into two categories; nociceptive pain (also called somatic or inflammatory pain) and neuropathic pain.  However, chronic pain conditions can have aspects of both of these categories of pain, and there is little consensus on classification of these pain syndromes.

Nociceptive pain results from injury or inflammation of somatic or visceral tissue such as muscoskeletal (rheumatoid arthritis, osteoarthritis, fibromyalgia) or lower back pain.  Nociceptive pain is typically described as dull, aching, throbbing pain that is sometimes sharp.  Nociceptive pain usually responds to pain medications, anti-inflammatory agents or other drug therapies.

Neuropathic pain is a malfunction of the nervous system due to injury, disease, or trauma such as diabetic neuropathy, postherpetic neuralgia, complex regional pain or HIV-related pain and usually is confined to a small area. Typically, neuropathic pain is described as burning, tingling, shooting, electric-like or lightning-like pain.

Mixed pain has both inflammatory and neuropathic components and may include muscoskeletal, lower back, cancer-related or complex regional pain.

Pain Treatment Market

NSAIDs, including COX-2 inhibitors, used to treat mild to moderate pain, are widely prescribed within the pain pharmaceutical market. NSAIDs are drugs with analgesic, fever-reducing and anti-inflammatory effects. As a class, NSAIDs are usually prescribed as first-line treatment; however, their relatively low potency may result in insufficient pain control for the patient. The long-term use of NSAIDs may result in side effects such as gastrointestinal bleeding, liver and kidney damage and cardiovascular-related complications.

Opioids have long been prescribed to treat moderate to severe pain and are regarded as the most potent class of analgesics. When used for extended periods, however, opioids can lead to intolerable side-effects, the development of tolerance, dependence and addiction. Tolerance means that increasing doses of opioids are required to maintain effective pain relief. Dependence means reliance on the drug and the existence of significant withdrawal symptoms upon cessation of drug administration. Addiction refers to drug-seeking behaviors characterized by a continued craving for the opioid and the need to use it for effects other than pain relief. As a consequence of these and other serious side effects, opioids are usually prescribed when other treatments for chronic pain have failed. In general, the more severe or chronic the pain, the more likely an opioid will be prescribed.

A Need for Improved Pain Therapies

Despite the availability of many drugs to treat chronic pain, the results of a 2006 survey of chronic pain sufferers conducted by the American Pain Foundation, found that approximately 51% of the respondents felt that they had little or no control over their pain.  CombintoRx believes that this lack of adequate pain control, particularly in patients with moderate to severe chronic pain, represents a significant therapeutic gap in current pain management. There is continued need across all chronic pain syndromes for novel agents with improved tolerability, enhanced efficacy, better long-term safety profiles and improved quality of life.