Treatment of chronic musculoskeletal pain with opioids

Abstract

Dear Editor, Our letter is inspired by the article of D Choquette, TG McCarthy, JFN Rodrigues, and coauthors [1]. We read it with great interest as it discusses important issues encountered by physicians who deal with chronic nonmalignant pain (CNMP) in the course of musculoskeletal disease. The article specifically relates to the use of opioids in patients with CNMP, with underlying musculoskeletal disease, who do not benefit fully from firstand second-step drugs of the World Health Organization (WHO) pain relief ladder. We have no intention to debate the mentioned article. We write in reference to the commonly expressed opinion that climbing the pain relief ladder in CNMP treatment is often done in a schematic way. In other words, it is believed that the lack of analgesic effect of step 1 and 2 drugs, in a patient whose pain intensity equals to 5 on the numerical pain scale, justifies the introduction of strong opioids. This is an approach which assumes that every kind of chronic pain is similar. It does not differentiate between malignant and osteoarthritic pain. The WHO pain relief ladder, initially created for cancer pain, was also adopted in practice for nonmalignant pain treatment. However, causes and sources of pain should not be ignored in relation to analgesic treatment. A priority in malignancy is to suppress pain and this does not interfere with the treatment of the underlying disease. In CNMP caused by musculoskeletal disease, treatment aims to maximize preservation of motor organ functions. In these patients, the intention to decrease pain is very important but it can sometimes be incompatible with maintaining maximal possible efficiency of motor organs after the termination of treatment. As an example, we show the case of our patient with hip joint pain and high-grade subchondral cysts in the femoral head and iliac acetabulum, awaiting an operation. Pain occurred mainly during movement and applying load to the joint. We may therefore ask whether it is prudent to remove pain and enable activity and loading of the joint, increasing the risk of femoral head fracture. Clinically, we all encounter many such examples. It should be remembered that opioids improve the quality of life but deprive the patient of the warning function of pain. Opioids also have adverse effects. They were discussed by the authors in their article. We would also remark on another adverse effect of opioids, important in treatment planning, which is their sedative potential. The risk of femoral neck fracture among persons taking opioids is increased 1.6-fold [2]. It results from the ability of opioids to impair balance and increase the risk of falls. This risk seems to be even higher among elderly people with advanced musculoskeletal disease. In persons with concomitant osteoporosis and/or atlantooccipital junction instability due to rheumatoid arthritis, falls can have serious consequences [3]. These factors should always be considered by a physician estimating risks and benefits for the patient. Opioids are an important class of drugs in the treatment of CNMP caused by musculoskeletal diseases. Their inclusion in the treatment of CNMP significantly improved the effectiveness of analgesia. They also counteract with mechanisms of pain chronification. Nevertheless, decisions concerning their introduction into CNMP treatment should not be schematic. Thus, as recommended by the American Clin Rheumatol (2008) 27:1473–1474 DOI 10.1007/s10067-008-0987-9