Re: Phantom limb pain
Dr Willms provided an excellent brief review of treatment considerations for patients with phantom limb pain [BCMJ 2021;63:291]. Dr Willms correctly indicated that phantom limb pain is not solely a result of centralized pain but a number of patients with phantom limb pain have centralized neuropathic pain. Dr Willms did not review standard pharmacological treatment for patients with centralized neuropathic pain. Standard pharmacological treatment includes either antidepressant medication, particularly tricyclic antidepressant medications and serotonin-norepinephrine reuptake inhibitors (SNRIs), or antiepileptic medications (such as gabapentin or pregabalin). Gabapentinoids, such as gabapentin and pregabalin have been shown to be efficacious in various neuropathic pain conditions, including phantom limb pain. Pregabalin may provide analgesia more quickly than gabapentin, is better absorbed and has higher bioavailability. Tricyclic antidepressive medications, such as nortriptyline (which has fewer side effects than amitriptyline), have analgesic effects for a variety of chronic pain states with or without coexisting depression. The SNRI antidepressant duloxetine has a large evidence base to support analgesic efficacy. Some patients with phantom limb pain can also benefit from topical agents, although they are usually prescribed as an adjunct to systematic medication. Cannabinoid-type drugs, such as cannabidiol, have not been extensively studied but may also have some benefit for this patient population.
Non-pharmacological intervention, as reviewed by Dr Willms, needs to be considered in all phantom limb pain patients, particularly if pharmacological strategies are ineffective, cause drug interactions, or cause significant side effects. Patients also need to be evaluated and treated for secondary emotional difficulties, including anxiety and depression, because both anxiety and depression increase pain perception and negatively affect one’s ability to cope with phantom limb pain.
—Stephen D. Anderson, MD, FRCPC
Vancouver
This letter was submitted in response to “Phantom limb pain: A brief discussion of treatment considerations including management of symptomatic neuromas.”
Read the author’s response in “Re: Phantom limb pain. Author replies.”