Conn's Current Therapy 1994 [antikvár]

Section Symptomatic Care Pending Diagnosis PAIN method of ALEXANDER MAUSKOP, M.D. New York Headache Center New York, New York PHARMACOTHERAPY Pharmacologic management has been the mainstay of treatment for many pain syndromes; however, nonpharmacologic therapies can at times be more effective and should not be used as methods of last resort. Examples include biofeedback for patients with headaches and physical therapy for patients with many forms of chronic low back pain. The three major groups of drugs used in pain management are nonsteroidal anti-inflammatory drugs (NSAIDs), opiates, and adjuvant medications. Nonsteroidal Anti-Inflammatory Drugs Aspirin and ibuprofen (Advil, Motrin) are sold over the counter, and many patients try them before seeking medical care. It is necessary for the physician to establish that the dosage and the frequency of self-administration were sufficient before giving up on this group of medications. Failure of one NSAID to relieve pain does not mean that another one is not effective. Side effects can also be idiosyncratic. Por example, naproxen (Naprosyn) and indomethacin (Indocin) can produce gastrointestinal side effects in a particular patient, whereas naproxen sodium (Ana-prox) and diclofenac sodium (Voltaren) do not. NSAIDs can be surprisingly effective in the relief of pain from metastatic bone disease. Opiates and NSAIDs have different mechanisms of action and together can have a synergistic effect. This combination may reduce the dose requirement of an opiate and consequently reduce its side effects. Longer acting NSAIDs, such as piroxicam (Fel-dene) given at 20 mg once a day, diflunisal (Do- lobid) given at 500 mg twice a day, choline or magnesium salicylate (Trihsate) given at 1500 mg twice a day, nabumetone (Relafen) given at 1000 mg once a day, and sustained-release indomethacin (Indocin SR) given at 75 mg once a day, are preferred in patients who have continuous pain. Short-acting NSAIDs include ibuprofen (Motrin, Advil) given at 400 to 600 mg every 4 hours, aspirin given at 650 to 1000 mg every 3 to 4 hours, and ketoprofen (Orudis) given at 50 mg four times a day. Ketorolac tromethamine (Tora-dol) is the first NSAID to be available in a parenteral form; the efficacy of a 30-mg intramuscular injection is comparable with that of an injection of 10 mg of morphine. Ketorolac (60 mg IM) has replaced dihydroergotamine (DHE-45) as the author's drug of first choice for office management of a patient with an acute migraine attack. Sometimes the author injects ketorolac in the office to relieve acute low back or neck pain. Opiates Important characteristics of opiate drugs and their relative potencies are shown in Table 1. Unlike NSAIDs, opiate drugs do not have a ceiling effect. This means that with the development of tolerance in order to regain pain relief, the dose of an opiate can be escalated indefinitely. Usually, the development of side effects limits such escalation, although some patients can tolerate an equivalent of up to several grams of morphine a day, given parenterally. These patients remain functional because gradual escalation of the dose leads to the development of tolerance not only to pain relief but also to side effects. The development of tolerance to an opiate is usually manifested by a shorter duration of action. Because cross-tolerance between different opiates is incomplete, switching to a different opiate may forestall escalation of the dose. Combinations of NSAIDs and adjuvant analgesics with opiates constitute another useful approach. Development of tolerance and physical dependence is often 1