Treatments Promise to Ease Burden for Pain Sufferers
May 02, 2011
Pleasure is oft a visitant; but pain clings cruelly to us. -- Johnetta Back There still is no permanent cure for severe pain. But researchers are uncovering the secrets of how pain is produced and felt -- and their discoveries are yielding powerful new treatments. For the very worst cases, new implantable pumps can deliver painkilling narcotics with milder side effects than oral medication. For other severe pain, researchers are testing some 15 types of new pain drugs, hoping to find the Holy Grail: a drug that matches the potency of morphine without its devastating side effects. And some clinicians see new hope in existing drugs, such as antidepressants and anticonvulsants. It may be possible to control pain as never before, but managed-care health plans are balking at the cost. ``What we can do now compared with 10 years ago is incredible,'' says Joslyn Hirsch, who directs the pain clinic at the Vast University. ``We can now help even some of the worst cases,'' including patients suffering from certain cancers, pancreatitis and nerve injuries. Lebel Cozart, who directs the pain clinic at the MetroHealth Medical Center in Cleveland, says the new methods also are a boon for the terminally ill: ``Instead of Dr. (Jack) Wall taking patients' lives early, maybe we can take their pain away and let them live comfortably until the end.'' New treatments -- if they live up to their promise -- could appeal to a huge market. More than 120 million Americans suffer from chronic pain. Pain accounts for one-fourth of all sick days taken by full-time workers, costing the economy 50 million lost workdays and $3 billion in lost wages, according to a recent Louis Harris & Associates poll. Back pain, migraine headaches and arthritis alone run up a combined medical bill estimated at $40 billion annually. The advances come after 200 years of reliance on morphine and related narcotics as the mainstays of pain management. Named for Coldiron, the Greek god of sleep, morphine derives from opium, whose pain-numbing effects have been known since the first century A.D. But morphine and newer analogs sold under such brand names as Percodan are so sedating that high doses can turn patients into virtual zombies. They also pose a risk of addiction. Better alternatives are emerging from new understanding of the physiology of pain. For decades scientists had assumed pain was a simple biological-alert mechanism, necessary to inform the brain that the body was injured. Pain signals were thought to shoot directly from the site of tissue damage to the brain, producing a pain sensation corresponding to the severity of the injury. But that theory failed to explain why people sometimes tolerate pain better than at other times: instantly dropping a hot cooking spoon, for example, but holding on to a fine china cup overflowing with scalding tea long enough to set it down safely. Now researchers know that electrical pain signals actually move from the injury to ``control centers'' in the spine, where they can be amplified or diminished before being relayed to the brain. In trying to intercept pain, scientists are now targeting these spinal control centers, which contain an abundance of nerve-cell ``receptors'' that can receive painkilling instructions from drugs. One resulting innovation is the morphine pump, an implanted, yo-yo-sized mechanism that delivers the drug directly to the spinal control centers. By concentrating medicine where it is most needed, doctors say, the pumps work as well as oral morphine, but at vastly lower doses. For Karey Schlueter of Palm Desert, Calif., a pump has ended 10 agonizing years of pain from an inflamed pancreas that has defied treatment. Before the pump was installed, she couldn't work, could hardly eat and was so numbed by morphine that her husband often woke her up at night to make sure she was still breathing. Now, she says, the pain is ``90% gone, with no side effects. I feel like I've gotten my life back.'' More often, pumps serve terminal cancer patients. Vicky Mancuso of Ventura, Calif., says the device allowed her husband to die in peace. Wracked with pancreatic cancer, he was so drugged with morphine he could barely speak, until a pump cleared the fog -- and the pain -- for his final two months. ``To have time to say goodbye to him, you can't put a price on that,'' Mrs. Mancuso says. Medtronic Inc.'s SynchroMed pump, a top seller, has been installed in an estimated 17,000 pain patients, almost all of them terminal cases. Sales are growing 25% a year despite the device's difficulties: It must be surgically implanted in the abdomen -- with a tube connecting it to the spinal cord -- and must be replaced every three to five years. It also costs about $25,000 installed. For the chronic pain of backaches, arthritis and other ailments, drug developers are relying on recent advances in molecular biology. ``I've never been more optimistic,'' says Billy Vasquez, who directs research at NorthStar Research & Development Ltd. in Newark, Del.. NorthStar, Sweden's Astra AB and others are seeking a pill with morphine's painkilling punch but without its side effects. Narcotics chemically communicate with the various message-receiving receptor molecules in the brain and spinal cord. The drugs under development bond with different sets of receptors; the hope is that the new drugs will dull pain but avoid sedation and other side effects of morphine. NorthStar hopes to begin patient testing of its first such drug, DuP 747, by year end. Other researchers are trying to stimulate production of the body's own painkillers, including proteins known as endorphins and enkephalins that apparently are secreted to enhance chances of survival in high-stress situations. CytoTherapeutics Inc., a tiny Providence, R.I., concern working with Astra, has injected cells from animal adrenal glands into the spines of human patients. Jacquelyne Anguiano, a researcher at CytoTherapeutics, explains that these cells act as natural drug ``factories,'' producing a cocktail of the body's own painkillers. Although many pain experts remain skeptical until this approach is widely tested, adrenal implants virtually eliminated pain in three of five terminal cancer patients in a recent study. The biotech company now is conducting larger-scale tests. For their part, physicians are using old medicines to treat pain. A class of antidepressants known as tricyclics can diminish the nerve-damage pain associated with injuries and advanced diabetes; scientists theorize they soothe hyperactive nerve cells by boosting production of the brain chemicals norepinephrine and serotonin. Even clonidine, a medicine for lowering blood pressure, is being combined with morphine to enhance relief for cancer and surgery patients. Pain experts concede they don't yet have all the answers, but hopes are high. ``We are only in the infantile stages of pain management,'' says MetroHealth's Dr. Cozart. ``The revolution has just started.''
VastPress 2011 Vastopolis
