Arthritis and serotonergic antidepressants

Antidepressant use in painful rheumatic conditions

This article reviews the pharmacologic and clinical evidence supporting the use of antidepressant drugs for treating painful rheumatologic conditions. Clinical studies have shown that tricyclic antidepressants, even at low doses, have analgesic effects in rheumatologic conditions equivalent to those of serotonin and noradrenalin reuptake inhibitors, but are less well tolerated. Selective serotonin reuptake inhibitors may also have analgesic effects, but higher doses are required to achieve analgesia in conditions such as fibromyalgia and low back pain. Antidepressant drugs may be useful in painful rheumatologic conditions, but in some studies the analgesic effects of antidepressants may be associated with functional impairment, sleep disorders, and fatigue. Further studies are required to determine antidepressants' analgesic mechanism of action and the specific role they should play in the management of chronic painful rheumatologic conditions.

Mirtazapine-induced arthralgia

AIM

With this article, we intend to corroborate the assumed association between mirtazapine and arthralgia by presentation of eight case reports, and we describe a possible mechanism of action.

METHODS AND RESULTS

The Netherlands Pharmacovigilance Centre Lareb received eight case reports on arthralgia associated with use of mirtazapine. These case reports are presented in short. We also present worldwide data on this association.

CONCLUSIONS

The Lareb reports support the association between mirtazapine and arthralgia. A comparison is made between mirtazapine, mianserin and nefazodone, as these antidepressants show similarities in their mode of action and are all associated with arthralgia. We suggest that this adverse drug reaction may be induced by enhanced 5HT1-mediated neurotransmission.

Guidelines for the use of antidepressants in painful rheumatic conditions

OBJECTIVES

Antidepressants are widely used to treat painful chronic rheumatic conditions but, contrary to neuropathic conditions, little is known about their true analgesic properties and value in these situations. Our group, which focuses on pain in rheumatology, aimed to develop recommendations for the use of antidepressants in rheumatology, based on evidence-based review of published data and expert opinion.

METHOD

We identified relevant drugs and conditions and searched Medline, Embase and Pascal (1966-2003) for relevant publications in a number of European languages. We scored each study for quality, and used an expert consensus approach to formulate recommendations.

RESULTS

We identified 77 studies and 12 meta-analyses and literature review on the use of antidepressant to treat painful rheumatological conditions. Forty-nine of these clinical studies were considered valid and were used to develop the recommendations. When evidence was lacking we based recommendations on our clinical experience.

CONCLUSIONS

These recommendations for the treatment of painful rheumatological conditions with antidepressants were developed using evidence-based and expert consensus approaches and are the first of their kind in this field. Our review of the literature highlights the need for further, well-designed clinical studies of the use of antidepressants to treat painful rheumatological conditions.

Interactions of acute morphine with chronic imipramine and fluvoxamine treatment on the antinociceptive effect in arthritic rats

This study was undertaken to investigate the effects induced by chronic systemic administration of two different antidepressants: imipramine (IMI), a dual serotonin-noradrenaline reuptake inhibitor, and fluvoxamine (FVX), a selective serotonin reuptake inhibitor, on the antinociceptive effect of morphine (MOR) in a paw pressure test in adjuvant-induced arthritic rats. For 30 days rats were administered with IMI, FVX or saline (SAL). On days 15 and 30, animals were tested in the paw pressure test 20 min after MOR or SAL administration. MOR induced a significant antinociceptive effect in IMI, FVX and SAL treated rats. But, at 30 days, this increase in pain threshold was significatively higher in IMI than SAL rats. This increase was not seen in FVX rats. These results suggest that a combination of opioid and mixed monoaminergic activities is effective in enhancing the antinociceptive effect of MOR in arthritic rats while only opioid and serotonergic activities have no enhancer effect.

Neuroendocrinology of autoimmunity

The HPA axis is fundamental for long-term survival and protection from the ravages of autoimmune disease. Continuing investigations suggest that the hypothesis linking susceptibility to autoimmune disease and a hyporesponsive HPA axis is somewhat simplistic. Instead, data from a number of different human diseases and from preclinical studies in a variety of models have suggested a more complicated picture. Alterations in the diurnal rhythms of ACTH, cortisol, and immune parameters appear to be linked to severity of disease. The use of low doses of steroids timed to target disrupted diurnal immune system changes in patients with RA may reduce the unfortunate side effects of long-term steroid use. Studies in cancer patients have related alterations in diurnal cortisol to survival. Whether differences in individual cortisol profiles are predictive of a deterioration in symptoms of autoimmune disease remains to be established. Responsiveness of the HPA axis to subtle challenges such as the dexamethasone suppression test and the related dexamethasone-CRF test suggest that there are different sub-populations of patients with RA and MS and these may have confounded earlier, apparently contradictory, studies. These different responses may be related to the severity of the disease. That these HPA axis differences can be altered beneficially through the use of antidepressants, as has been shown in MS, may impact on future health care strategies. However, reports of negative developments in arthritis associated with SSRI use suggest that the SSRIs may be unsuitable under some circumstances. The link of behavioral differences to alterations in neurotransmitter changes associated with disease is intriguing and opens new avenues of research. These future studies will require input from neuroscientists, neuroendocrinologists, psychologists, and immunologists working with the clinical specialties already involved in treating patients with autoimmune disease. These multidisciplinary studies reflecting the increased importance of hormonal and neurotransmitter involvement with the immune system hold great promise for the future.