Clinical
Pharmacy Practice News • February 2021
7
Pain Medicine
Muscle Relaxants and Chronic Pain a Dangerous Mix
I
n what can be seen as a sign of a distressing trend considering current prescribing guidelines and the shortage of data on efficacy, the long-term use of skeletal muscle relaxants (SMRs) to treat pain appears to be on the rise. More concerning is that repeat prescriptions in older adults (over 65 years)— a patient population for whom guidelines advise against prescribing this class of drugs—nearly tripled in the last decade.
The findings emerged from a study of 300 million U.S. ambulatory care office visits. More than 30 million of those visits during 2005-2016 resulted in a prescription for an SMR for the first time or as part of ongoing therapy. Overall, the researchers wrote, “Office visits with a prescribed SMR nearly doubled, from 15.5 million in 2005 to 30.7 million in 2016” (JAMA Netw Open 2020;3[6]:e207664). Although initial prescriptions of an
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SMR remained somewhat stable over that period, the team found that repeat prescriptions accounted for much of the increase, nearly tripling in all age groups (8.5 million in 2005; 24.7 million in 2016). “Given that there are minimal data on long-term safety and effectiveness, and these drugs are not indicated for use beyond a couple of weeks of therapy, it starts to raise [a] red flag,” said Charles Leonard, PharmD, an
HyperRAB
-----------DOSAGE FORMS AND STRENGTHS---------300 IU/mL solution for injection supplied in 1 mL, 3 mL and 5 mL single-dose vials.
HIGHLIGHTS OF PRESCRIBING INFORMATION
--------------------CONTRAINDICATIONS--------------------None.
Rabies Immune Globulin (Human) These highlights do not include all the information needed to use HYPERRAB® safely and effectively. See full prescribing information for HYPERRAB. HYPERRAB [rabies immune globulin (human)] solution for infiltration and intramuscular injection Initial U.S. Approval: 1974 ----------------INDICATIONS AND USAGE------------------HYPERRAB is a human rabies immune globulin indicated for postexposure prophylaxis, along with rabies vaccine, for all persons suspected of exposure to rabies. Limitations of Use Persons previously immunized with rabies vaccine that have a confirmed adequate rabies antibody titer should receive only vaccine. For unvaccinated persons, the combination of HYPERRAB and vaccine is recommended for both bite and nonbite exposures regardless of the time interval between exposure and initiation of postexposure prophylaxis. Beyond 7 days (after the first vaccine dose), HYPERRAB is not indicated since an antibody response to vaccine is presumed to have occurred. --------------DOSAGE AND ADMINISTRATION------------For infiltration and intramuscular use only. Administer HYPERRAB within 7 days after the first dose of rabies vaccine. Postexposure HYPERRAB • Administer as soon prophylaxis, 20 IU/kg as possible after along with body weight exposure, preferably rabies OR at the time of the first vaccine, after 0.0665 mL/kg rabies vaccine dose. suspected body weight • Infiltrate the full exposure to dose of HYPERRAB Single dose rabies thoroughly in the area around and into the wound(s), if anatomically feasible. • Inject the remainder, if any, intramuscularly.
-------------WARNINGS AND PRECAUTIONS-------------• Severe hypersensitivity reactions, including anaphylaxis, may occur with HYPERRAB. Have epinephrine available immediately to treat any acute severe hypersensitivity reactions. • HYPERRAB is made from human blood; it may carry a risk of transmitting infectious agents, e.g., viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent, and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent. --------------------ADVERSE REACTIONS--------------------The most common adverse reactions in >5% of subjects in clinical trials were injection site pain, headache, injection site nodule, abdominal pain, diarrhea, flatulence, nasal congestion, and oropharyngeal pain. To report SUSPECTED ADVERSE REACTIONS, contact Grifols Therapeutics LLC at 1-800-520-2807 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. --------------------DRUG INTERACTIONS------------------• Repeated dosing after administration of rabies vaccine may suppress the immune response to the vaccine. • Defer live vaccine (measles, mumps, rubella) administration for 4 months.
assistant professor of epidemiology at the University of Pennsylvania’s Perelman School of Medicine, in Philadelphia, and senior author of the paper. Possibly the most concerning aspect of this study is that adults 65 years and older account for nearly one-fourth (22.2%) of the office visits. The increase in SMR use occurred despite the fact that these drugs have known adverse effects in older patients and are never the recommended course of action to treat pain in this patient population. “Muscle relaxers can cause confusion at all ages, but [that effect is heightened] in the elderly,” said Kimberly Croley, PharmD, a clinical pharmacist at Laurel Senior Living Community, in London, Ky. However, her concern for her patients goes beyond increased risks for falls and fractures or motor vehicle accidents, pointing out that SMRs are not pain relievers at all, since they don’t treat a patient's pain or reduce inflammation. Instead, relief often comes from the sedative properties of these drugs. A sleeping patient, by definition, is a patient free from pain, she noted. A frequent source of pain in patients of this age group is procedures such as reconstructive hip or knee surgery, and proper recovery requires physical and occupational therapy to normalize a patient’s mobility levels. “But how do you rehab someone who sleeps all the time?” Croley asked. Her answer, simply, is “You don't.” As a result, “[patients] don’t get the benefit of the surgery. In some instances, the joint can almost become frozen.”
Digging Deeper Why is SMR use increasing? Leonard cited the fact that “treatment of persistent pain is incredibly challenging, and can be complicated by medical, psychological, social and environmental factors. As providers may hesitate to prescribe opioids, there are few pharmacologic treatment options available beyond acetaminophen or nonsteroidal anti-inflammatory drugs.” Croley said focusing on SMRs isn’t the answer. More than anything else, she feels that greater provider involvement, including a treatment plan, education of patient and caregivers, and messaging, are vital in addressing patients’ pain. “I’m a pharmacist. I should want people to take pills, but that’s not always the answer. Part of medical care should be not just chemistry, but a lifestyle,” she said. “When we have an acute illness, we will only treat the acute illness in the short term, as necessary, to get past it. Then we go back to focusing on wellness.” —W. Harry Fortuna
Grifols Therapeutics LLC Research Triangle Park, NC 27709 USA U.S. License No. 1871
3054805 Revised: 11/2019
The sources reported no relevant financial disclosures.
