Antidepressants for pain in rheumatic condition

For the first time, guidelines on the use of antidepressants in painful rheumatic conditions have been drawn up and are published online before print in the European Journal of Pain. The authors, headed by Dr Serge Perrot (Hopital Cochin-Tarnier, Paris, France), are from a subgroup of the French Society of Rheumatology and have a specific interest in rheumatic pain.

Pain is the main symptom of many rheumatic and inflammatory conditions, and when it cannot be controlled effectively with analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), or opioids, additional treatment with an antidepressant may be helpful, the authors comment. Although the use of antidepressants is increasing for conditions such as fibromyalgia, rheumatoid arthritis, spondylarthropathies, and osteoarthritis (OA), there are questions concerning the use of these drugs. For instance, does the analgesic effect depend on the antidepressant effect? When is such treatment appropriate and how long should it be continued? In an attempt to answer some of these questions, the authors reviewed the medical literature (from 1996 to 2002) and also drew on expert opinion within the group. The panel comprised seven rheumatologists, one psychiatrist, and one neurologist; two of the members were also pharmacologists. They present the document as “a starting point for discussion” and designed it to be “flexible enough to gain practical acceptance in different countries.”Tricyclics are first choice for analgesiaThe analgesic effects of antidepressants have been demonstrated most convincingly for tricyclic antidepressants (TCAs), such as amitriptyline, but the evidence is “conflicting” for selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, the authors note. The analgesic effects appear to be independent of the effect on mood; pain relief is usually observed within one week of starting treatment, whereas the antidepressant effect usually occurs after the first two weeks. But side effects are similar whether the drugs are used to treat pain or depression.Before initiating treatment with a TCA, the physician should check for orthostatic hypotension and perform an electrocardiogram, the group notes. In elderly patients starting TCAs, physicians should monitor blood pressure, cognition, and intestinal transit. No tests are necessary before initiation of treatment with an SSRI. Assessment of treatment efficacy should not be limited to pain evaluation but should also include functional evaluation, analgesic consumption, sleep evaluation (quality and duration), and psychological assessment. These should be started after one week of treatment. The first choice of antidepressant for pain in patients who are not depressed is a TCA, initiated at low dose and then increased to the maximal-tolerated or minimal-effective dose. Antidepressant therapy should be integrated into a global management program along with nonpharmacological approaches, the experts write. There is no optimal duration, but treatment should last for at least four weeks before being stopped for lack of efficacy. After three to six months of remission, the dose may be gradually decreased; stopping abruptly may precipitate side effects (nausea, vomiting, trembling).Rheumatic conditionsThe experts also reviewed the clinical-trial data available for individual rheumatic conditions and add the following comments:In fibromyalgia, TCAs are used at doses lower than they are for depression, probably because of the side effects of these drugs. Despite their widespread use, TCAs have only a moderate effect, and only a minority of patients display sustained, marked improvement. SSRIs are better tolerated but less effective, making it necessary to increase the dose to obtain significant pain relief. For chronic low-back pain, tricyclic and tetracyclic antidepressants appear to moderately reduce symptoms independent of a patient’s depression status. SSRIs do not appear to be beneficial. In rheumatoid arthritis, amitriptyline, trimipramine, dothiepine, and paroxetine may have analgesic effects. In ankylosing spondylitis, amitriptyline may be useful in reducing symptoms. Low doses of amitriptyline (10-30 mg) may be sufficient to produce an analgesic effect.None of the studies included in the review dealt specifically with OA, but a large study of older patients with arthritis (mostly OA) and comorbid depression found benefits that extended beyond the reduction of depressive symptoms and included decreased pain and improved functional status and quality of life.The authors conclude that antidepressants are recommended as analgesics for fibromyalgia, especially TCAs, but they should not be first-line analgesic treatment in low-back pain, osteoarthritis, or inflammatory rheumatic painful diseases. (Source: Perrot S, Maheu E, Javier RM, et al. Guidelines for the use of antidepressants in painful rheumatic conditions. Eur J Pain 2005; DOI:10.1016/j.ejpain.2005.03.004. Available at: http://www.sciencedirect.com: Joint and Bone: September 2005 Rheumawire).