Treatment of Challenging Cancer Pain Requires Close Monitoring

SALT LAKE CITY—Choosing appropriate treatment options and then following strict monitoring parameters are essential for patients with challenging cancer pain, according to a presentation at the annual meeting of the Hematology/Oncology Pharmacy Association.

“Cancer patients with pain have risks too. So risk stratification and risk minimization should be employed for all patients,” said David S. Craig, PharmD, BCPS, from the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Florida.

“Methadone pearls” from a recent study recommend an electrocardiogram for any high-risk patients (such as those at risk for heart rhythm disturbances) when concurrent QT prolonging drugs are used or there are significant drug– drug interactions, when treatment doses are higher than 100 mg/day, if an intravenous line is used, or if there are electrolyte abnormalities (Krantz M, et al. Ann Intern Med. 2009;150:387-395).

Also, “if current QTc is greater than 450 msec but less than 500 msec, monitor more frequently. If it is greater than 500 msec, watch out!” said Craig.

He added that risk assessments can be conducted with the 5-question Opioid Risk Tool “to predict opioidrelated aberrant behavior,” the 17-item patient-assessed Current Opioid Misuse Measure, and the 24-item Screener and Opioid Assessment for Patients with Pain–Revised.

For patients deemed at high risk for abuse, potential strategies can include frequent office visits, random urine drug screenings, and patient–provider agreements. In addition, Craig recommended considering less abusable formulations, consultations with addiction specialists, and family member in volvement.

When patients use opioids, monitoring parameters should include watching for constipation, sedation, or lethargy and keeping continuous watch of alanine transaminase/aspartate transaminase (AST/ALT) and renal function. For nonsteroidal antiinflammatory drugs or corticosteroid use, gastrointestinal bleeding and renal and cardiovascular risks should be monitored; AST/ALT and serum creatinine should be watched when antiepileptics are used; anticholinergic side effects, QT prolongation, and suicide risk should be monitored for tricyclic antidepressants; and anticholinergic side effects, AST/ALT, and suicide risk should be watched with use of serotonin-norepinephrine reuptake inhibitors.

Several resources offering guidance are available to oncology pharmacists, including the upcoming “Opioid Drugs and Risk Evaluation and Mitigation Strategies (REMS), Guidelines for the Management of Cancer Pain in Adults and Children” by the American Pain Society (www.ampain soc.org), and recommendations by the National Comp rehensive Cancer Network (www.nccn.org) and the National Cancer Institute (www.cancer.gov).

In addition, the state of Washington has released noncancer pain management guidelines, whereas Utah and Oklahoma as well as the government of Canada have released guidelines on prescribing opioids.

“Always remember adjuvants, other alternatives, outcomes, and treatment plans” for cancer pain, summarized Craig. “And although opioids remain the mainstay, think outside the box when necessary.”