Pain Management in Metastatic Bone Disease

Fig. 15.1
A modification of the World Health Organization ladder of pain management showing contemporary pain management techniques. From Fine PG. The evolving and important role of anesthesiology in palliative care. Anesth Analg 2005; 100:183–188. Reprinted with permission from Wolters Kluwer Health

A careful history will help the practitioner tailor the treatment plan to offer the best chance of clinical success. It is important to correlate symptoms and what is known about disease extent and location. For example, a solitary, painful metastatic lesion may be best treated with radiation therapy, whereas more extensive disease will require systemic therapy with analgesics.

It is also important to distinguish between nociceptive versus neuropathic, described above, as the treatments are quite different. Neuropathic pain is characterized by features such as a burning, tingling, and associated neurologic dysfunction. Nociceptive pain is most often characterized as “aching,” more localizable, and exacerbated by movement.

If the history supports an acute onset of pain, a pathologic fracture must be considered, and therapy will depend on the clinical and imaging findings. For example, select acute vertebral compression fractures will respond well to percutaneous vertebral augmentation techniques such as kyphoplasty or vertebroplasty.

When considering initiation or modification of an analgesic regimen, it is important to consider what medications have already been tried and whether a therapeutic response was obtained. A historical benefit with NSAIDs should be noted, including screening for side effects and contraindications.

It is also imperative that prior to initiating therapy with opioids, screening is performed for a patient history of substance abuse—a positive history will obviously complicate management and obtaining additional help from a palliative care, or pain, specialist should be considered.


Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

The use of nonsteroidal anti-inflammatory agents (NSAIDs ) or acetaminophen has been established as the initial step in cancer pain management by the World Health Organization [7]. While the WHO algorithm has been greatly expounded upon since its inception, the use of NSAIDs and acetaminophen endure as mainstays of initial cancer pain treatment. Patient familiarity, widespread access, low cost, and ease of use all contribute to the advantageous nature of NSAID use in cancer pain management.


NSAIDs are a diverse group of drugs broadly categorized into salicylates (e.g., aspirin), propionic acid derivatives (e.g., ibuprofen), acetic acid derivatives (e.g., ketorolac), oxicam derivatives (e.g., piroxicam), and the heterocyclics (e.g., celecoxib). See Table 15.1 for a list of common NSAIDs and their properties.

Table 15.1
Summary table of nonsteroidal anti-inflammatory drugs and acetaminophen


Common trade name

Half-Life (h)

Typical daily dose range

Typical dosing schedule

Typical pediatric dosing, mg/kg/24 h



Tylenol, Panadol


2–4 g

325–650 mg Q4 h

10–15 mg/kg q6–8 h prn

Propionic acid derivatives




1.2–2.4 g

300–600 mg QID

900–1800 mg per body surface area in M2




200 mg

100 mg BID



Motrin, Advil, Brufen Caldolor (iv) , others


1.2–2.4 g

400–800 mg QID

7.5–10 mg/kg QID

Higher doses sometimes used for inflammatory conditions; max dose 3200 mg/day




225 mg

75 mg TID





750–1000 mg

250–375 mg BID

5–10 mg/kg BID

Naproxen Sodium

Alleve, Anaprox


550–1100 mg

275–550 mg BID

5–10 mg/kg BID






50 mg TID

75 mg BID

2–3 mg/kg/24 h




800–2400 mg

400–800 mg TID

20–30 mg/kg/24 h as 3–4 doses




IV: 60 mg/daya

30 mg first dose; then 15 mg q6 ha

IV: 0.5 mg/kg/day, single dose only.

Only parenteral agent available

Enolic acid derivatives (oxicams)





7.5–15 mg QD.


Higher dose typically used for rheumatoid arthritis.




20 mg

10–20 mg QD





1000–1500 mg

500–750 mg BID


Acetic acid derivatives




400–1200 mg

200–400 mg TID/QID

15–20 mg/kg/24 h

iv intravenous

aHalf the dose if age >65 years or <50 kg

Mechanism of Action

All NSAIDs act by inhibition of prostaglandin synthesis. Prostaglandins have important physiologic functions including the mediation of the inflammatory response, the transduction of pain signals, as well as a central antipyretic effect. Prostaglandins are derived from arachidonic acid via a reaction catalyzed by cyclooxygenase (COX) enzymes. By inhibiting COX enzymes NSAIDs block production of prostaglandins from arachidonic acid.

The COX enzymes are known to exist as three isoforms: COX-1, COX-2, and COX-3. COX-1 and COX-2 are the isoforms nonspecifically targeted by the traditional NSAIDs, while the more selective COX-2 inhibitors preferentially block COX-2. COX-1 is involved in normal physiologic functioning such gastrointestinal mucosal protection and hemostasis. COX-2, on the other hand, is inducible during physiologic stress by agents including pro-inflammatory cytokines, neurotransmitters, and growth factors. Although both enzymes are structurally similar and act in the same fashion, their respective gene expression profiles and selective inhibition can determine NSAID side-effects and toxicity.

Evidence for NSAID Use in Cancer Pain

Studies investigating short term NSAID use in cancer pain management consistently demonstrate a dose-related improvement in pain relief compared to placebo with no increase in side effects. However, the longer-term efficacy and tolerability of NSAIDs is not well established. In modern oncology practice, with often-prolonged survivorship, the sequelae of longer-term NSAID use, such as renal toxicity, gastric ulceration, and increased cardiovascular risk, should be considered [8].

Side by side comparison of NSAIDs, including the COX-2 inhibitors, fails to demonstrate superiority of pain relief from any one formulation. These studies also fail to show significant difference in side effects across the NSAID spectrum. Assuming there are no contraindications to NSAID use, including renal insufficiency or active gastrointestinal ulceration, NSAIDs should be trialed in most cancer pain patients. After initiating an NSAID, regular screening for efficacy and toxicity should be implemented, with discontinuation of the drug if inefficacy or toxicity is observed. Celecoxib, the only remaining COX-2 inhibitor on the US market, has less gastrointestinal toxicity during short term use, yet controversy remains about whether there is any difference, compared to nonselective NSAIDs, beyond 6 months. Finally, celecoxib enjoys the advantage of lacking an antiplatelet effect, but does have similar renal toxicity compared to nonselective NSAIDs.

Toxicities and Risks

The use of NSAIDs in management of cancer pain may be precluded by comorbidities or concurrent treatments such as chemotherapy. Side effects and toxicities of NSAIDs present in the general population are often augmented in patients being treated for cancer due to additional treatments or overall poor state of health. In particular, NSAIDs should be prescribed with caution in patients at increased risk for renal, gastrointestinal, or cardiac toxicities as well as those with bleeding disorders or thrombocytopenia [9].

Renal Toxicity

All NSAIDs can transiently decrease renal function in selected patients, resulting in hypertension, edema, and even acute renal failure. Patients at elevated risk for renal toxicities from NSAID treatment include: age greater than 60 years old, compromised fluid status, interstitial nephritis, papillary necrosis, and concurrent administration of nephrotoxic drugs, including cyclosporine and cisplatin. Further, any chemotherapy drugs excreted renally elevate the risk for toxicity.

If the patient’s serum creatinine is elevated or shows a trend towards elevation, the NSAID should be discontinued.

GI Toxicity

The chronic use of NSAIDs inhibits production of prostaglandins that maintain normal gastrointestinal mucosal integrity, and results in gastric and colonic mucosal damage including erosion and ulceration. Patients at increased risk for GI toxicity include: age greater than 60 years old, history of peptic ulcer disease or significant alcohol use, major organ dysfunction (including hepatic), and use of high-dose NSAIDs for a long duration.

If a patient develops mild to moderate gastric symptoms (dyspepsia, abdominal pain, nausea) discontinuation of NSAIDs should be considered. Alternatively, the patient could be switched to a COX-2 inhibitor due to their lower incidence of GI side effects. Drugs that decrease gastric acidity including antacids, H2 receptor antagonists, or proton pump inhibitors may ameliorate GI side effects.

Certain gastrointestinal conditions should prompt immediate discontinuation of NSAIDs. These include presence of gastrointestinal peptic ulcers, gastrointestinal hemorrhage, and an increase in liver function studies 1.5 times the upper limit of normal.

Cardiovascular Toxicity

All NSAIDs, including COX-2 specific agents, can increase the risk of serious cardiovascular thrombotic events such as myocardial infarction and stroke. In addition, NSAIDs may increase blood pressure, and this is likely linked to the increased cardiovascular risks associated with their use. Patients at increased risk for cardiac toxicities include: prior history of cardiovascular disease or those at increased risk for cardiovascular disease or complications due to factors such as a history of smoking or known family history. Further, patients currently using anticoagulants are at significantly increased risk for bleeding complications when placed on concurrent NSAID therapy—NSAID use should be avoided in these patients.

Bone Healing

Bone healing is dependent upon an inflammatory response involving numerous cytokines and fibroblast growth factor, so it should not be surprising that an agent that disrupts normal cytokine function may impair bone homeostasis and repair [10]. In fact, this inhibitory healing response has been used therapeutically to prevent heterotrophic bone formation after arthroplasty [11].

However, data on detrimental effects of NSAID use in the perioperative period is somewhat conflicted and controversial [12]. The issue of bone healing and NSAIDs has been addressed most thoroughly in the spinal fusion literature. A retrospective analysis of 288 patients who underwent instrumented spinal fusion from L4 to the sacrum demonstrated a fivefold higher nonunion rate when ketorolac was used in the immediate postoperative period [13]. In direct contrast to this, another retrospective study was performed in which 405 consecutive patients who underwent primary lumbar spinal fusion—a subset of these patients who received ketorolac 30 mg intravenously every 6 h for 2 days had similar fusion rates to a group that had no NSAIDs [14]. A metanalysis of 5 retrospective studies explored the relation of ketorolac dose and successful spinal fusion rates, and concluded that high dose ketorolac (dose > 120 mg/day) may be associated with poor outcomes, whereas standard dose ketorolac (<120 mg/day) was not [15]. Considering the absence of any prospective or randomized studies as well as the high morbidity associated with bony nonunion, use of perioperative nonselective NSAIDs in spinal fusion cases should be considered carefully, particularly when other risk factors for poor bone healing (i.e., smoking) exist. In non-spine orthopedic surgery there is good evidence of NSAID analgesic efficacy without significant compromise of bone healing [12, 16].


Opioid-based analgesia remains the cornerstone of pain management in cancer patients and postoperative pain. Opioids are indicated when NSAIDs are insufficient for adequate pain relief or when patients have contraindications to NSAIDs. Ideal opioid regimens are individualized to each patient. The prescriber should recognize the wide dosing variability that exists in the population rather than adhering to a standard dosing protocol. Careful titration of opioids optimizes pain relief while minimizing adverse side effects such as constipation, nausea, respiratory depression, and sedation.

A Practical Approach to Opioid Management in Cancer Pain

Before initiating opioid therapy in any patient it is important to establish goals of care, i.e., short-term postoperative use versus longer-term management for chronic, cancer -related, pain. Patients must be screened for a personal history of drug abuse and serious mood problems. Urine drug toxicology should be considered if there is a suspicion for illicit drug use. Patients must be educated on the safe use, storage, and disposal of their medication [17].

Typically, short-acting opioids are prescribed first, on an as-needed basis. In many countries the short-acting opioids, such as hydrocodone and oxycodone, are formulated with acetaminophen so it is imperative that the total daily dose of acetaminophen does not exceed 4000 mg/day (see Table 15.2). If the acetaminophen dose ceiling is approached, changing to a non-acetaminophen containing product is advised.

Table 15.2
Commonly used opioids


Common formulations

Common trade names

Typical starting dose

Approximate dose equivalencea



5, 7.5, 10 mg acetaminophen 325 or 500 mg/pill




5/325 mg, 1–2 pills q4 h prn, max 10 pills/day

10 mg

Caution with acetaminophen containing products: keep total daily dose <4000 mg/day


IR: 5, 10, 15, 30 mg

ER: 10, 15, 20, 30, 40, 60, 80 mg

Percodan® (APAP)

Percocet® (APAP)



Immediate release: 5 mg, 1–2 pills q4 h prn.

Extended release: 10 mg BID

7.5 mg

See acetaminophen comment above


IR: 15, 30, 60 mg

ER: 15, 30, 60, 100, 200 mg

ER: MsContin ®, Kadian ®

IR: 15 mg q4 h prn.

ER: 15 mg po BID

10 mg

Caution in advanced renal insufficieny—metabolites may accumulate


IR: 2, 4, 8 mg

ER: 8, 12, 16, 32 mg

ER: Exalgo ®

IR: 2 mg po q4 h prn

ER: 8 mg po QD

2 mg


ER: 12, 25, 50, 75, 100 mcg/h

ER: Duragesic ®

ER: 25 mcg/h, changed q3 days

See manufacturer’s prescribing information

Only for use in opioid tolerant patients

IR products such as Actiq® available, but probably best prescribed by a pain or palliative care specialist


IR: 50 mg

ER: 100, 200, 300 mg

IR: Ultram ®

ER: Ultram ER ®

IR: 50–100 mg q6 h prn

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Jun 4, 2017 | Posted by in ORTHOPEDIC | Comments Off on Pain Management in Metastatic Bone Disease

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