Page 163 Guide to Pain Management in Low-Resource Settings

Osseous Metastasis with Incident Pain 151

Radiotherapy is successful in relieving pain in 60–70% to prevent withdrawal in recovering drug users, is used
of patients, but it takes up to 3 weeks for the full eff ect in hospices in the United Kingdom and Canada. It is
to be seen. also used in the United States for the treatment of pa-
Potential complications of radiation include sys- tients with refractory or neuropathy-associated pain.
temic side eff ects not confi ned to the area of irradiation, Numerous opioid preparations are now avail-
such as nausea and vomiting, anorexia, and fatigue, as able. Currently, immediate-release forms of morphine,
well as eff ects specifi cally related to the irradiation fi eld, oxycodone, and hydromorphone are available for a fairly
including skin lesions, gastrointestinal symptoms, my- rapid onset of drug action. Sustained-release (SR) prep-
elosuppression, and alopecia. Th e best treatment for arations (morphine, oxycodone, or hydromorphone) are
hypercalcemia due to cancer is treatment of the cancer eff ective in dosing every 12 or 24 hours, or sometimes
itself. However, since hypercalcemia often occurs in pa- every 8 hours. Th ey are usually used after dose titration
tients whose cancer is advanced or has not responded to defi ne the eff ective daily dose for baseline continu-
to treatment, management of hypercalcemia is some- ous pain. Fentanyl is now also available in two forms of
times necessary. immediate-release preparations—the transmucosal for-
mula and sustained-release transdermal patches.
Radionuclides
Long-term use of opioids is associated with
Radionuclides that are absorbed at areas of high bone physical dependence and (rarely) tolerance. Tolerance
turnover have been assessed as potential therapies for is defi ned as a physiological phenomenon of progressive
metastatic bone pain. Strontium-89 chloride and samar- decline in the potency of an opioid with continued use,
ium-153 are available in the United States. manifested by the requirement of increasing opioid dos-
es to achieve the same therapeutic eff ect. Increased dos-
How is osseous pain treated? es can continue to provide adequate analgesia because
there appears to be no ceiling eff ect, but escalating dos-
Analgesic drugs es can increase side eff ects (nausea, vomiting, constipa-
Nonsteroidal anti-infl ammatory drugs (NSAIDs) and tion, abdominal pain, and pruritus) that may limit their
COX-2 inhibitors are promising as anticancer drugs use. At this point, opioid rotation is needed.
because they inhibit tumor angiogenesis and induce tu-
mor cell apoptosis. NSAIDs play a key role in the fi rst Coanalgesics
step of the WHO guidelines for management of cancer Steroids, including corticosteroids, have benefi cial ef-
pain. Nearly 90% of patients with bone metastasis pres- fects in reducing metastatic bone pain, due to their an-
ent with pain. NSAIDs are the most eff ective agents for ti-infl ammatory properties in blocking the synthesis of
treatment of patients with this condition because pros- cytokines, which can contribute to both infl ammation
taglandins appear to play an important role. Th ey are and nociception. Th e duration of pain relief is general-
comparable in safety profi le and eff ectiveness. Compari- ly short. Special consideration should be given to these
son of opioid combination preparations with NSAIDs drugs in cases of spinal cord and brain compression, in
alone showed no or at most only a slight diff erence. which their role in reducing peritumoral edema is very
Continuous bone pain shows a good response advantageous. Th ey are eff ective and can sometimes
to opioids. Most terminally ill patients with incident temporarily stabilize or improve neurological dysfunc-
pain found that pain was a major limiting factor to ac- tion. Although corticosteroids are part of the treatment
tivity. Th e diffi culty with incident pain is not a lack of in advanced cancer patients for their benefi ts regarding
response to systemic opioids, but rather that the doses improved appetite, reduced fatigue, and a sensation of
required to control the incident pain produce unaccept- well-being, prolonged use should be weighed against
able side eff ects when the patient is at rest. Oral mor- the adverse eff ects. Serious complications of prolonged
phine is the primary opioid used in the United States administration of corticosteroids include immunosup-
for treatment of patients with severe pain in advanced pression, pathological fractures, swelling, and delirium.
stages of cancer. In the United Kingdom, diamorphine Calcitonin, a hypocalcemic agent, may be use-
(heroin) is used secondarily because of its greater solu- ful as an adjuvant analgesic. Calcitonin inhibits sodium
bility, but it has no clinical advantage over morphine. and calcium resorption by the renal tubules and reduces
Methadone hydrochloride, a drug commonly prescribed osteoclastic bone resorption. However, despite its rapid