Duloxetine Plasma Concentrations and Its Effectiveness in the Treatment of Nonorganic Chronic Pain in the Orofacial Region.

OBJECTIVE: The purpose of this study was to examine the relationship between the pain-relieving effects of duloxetine and its plasma concentrations in patients with burning mouth syndrome and atypical odontalgia characterized by chronic nonorganic pain in the orofacial region. METHODS: We administered duloxetine to 77 patients diagnosed as having burning mouth syndrome or atypical odontalgia for 12 weeks. The initial dose of duloxetine was established as 20 mg/d and was increased to 40 mg/d after week 2. We evaluated pain using the visual analog scale and depressive symptoms using the Structured Interview Guide for the Hamilton Depression Rating Scale at weeks 0, 2, 4, 6, 8, 10, and 12 and measured plasma concentrations of duloxetine 12 weeks after the start of its administration. RESULTS: Visual analog scale scores were significantly lower 12 weeks after than at the start of the administration of duloxetine (paired t test, t = 6.65, P < 0.0001). We examined the relationship between the rate of decreases in visual analog scale scores and plasma concentrations of duloxetine. There was no significant linear regression or quadratic regression. CONCLUSIONS: Duloxetine significantly relieved pain in patients with chronic nonorganic pain in the orofacial region. However, no relationship was observed between its pain-relieving effects and plasma concentrations.

Five Patients With Burning Mouth Syndrome in Whom an Antidepressant (Serotonin-Noradrenaline Reuptake Inhibitor) Was Not Effective, but Pregabalin Markedly Relieved Pain.

Burning mouth syndrome (BMS) causes idiopathic pain or a burning sensation in clinically normal oral mucosa. Burning mouth syndrome is a chronic disease with an unknown etiology. Burning mouth syndrome is also idiopathic, and a consensus regarding diagnosis/treatment has not been reached yet. Recent studies have supported the suggestion that BMS is a neuropathic pain disorder in which both the peripheral and central nervous systems are involved. Tricyclic antidepressants (nortriptyline and amitriptyline), serotonin-noradrenaline reuptake inhibitors (SNRIs) (duloxetine and milnacipran), and antiepileptic drugs, potential-dependent calcium channel α2δ subunit ligands (gabapentine and pregabalin), are currently recommended as the first-choice drugs for neuropathic pain. In this study, we report 5 patients with BMS in whom there was no response to SNRI (milnacipran or duloxetine), or administration was discontinued because of adverse reactions, but in whom pregabalin therapy markedly reduced or led to the disappearance of pain in a short period. Pregabalin, whose mechanism of action differs from that of SNRIs, may become a treatment option for BMS patients who are not responsive to or are resistant to SNRIs.

Temperament and character profiles of patients with burning mouth syndrome.

OBJECTIVE: Burning mouth syndrome (BMS) is a chronic disease in which patients feel a burning sensation and pain in the oral cavity. Although personality traits have been suggested to influence the development and course of BMS, they have not yet been examined in detail. We therefore investigated the personality traits of BMS patients. METHODS: Sample consisted of 65 BMS patients presenting to the Aichi-Gakuin Dental School Hospital between May 2005 and April 2009. They were also diagnosed as having pain disorder by a psychiatrist. The control group consisted of 116 healthy subjects. The Temperament and Character Inventory (TCI) was used to evaluate personality traits, while the Beck Depression Inventory (BDI) was used to evaluate the depression rate in both groups. RESULTS: In TCI, we found that, in comparison to the control group, the novelty seeking score was significantly lower (p = 0.009), the harm avoidance score was significantly higher (p < 0.001), and the self-directedness score was significantly lower (p = 0.039) in the BMS group. To remove the influence of depression, we performed an analysis of covariance of each TCI item using the BDI score as a covariate. No significant differences were observed in harm avoidance or self-directedness, whereas the differences noted in novelty seeking were significant (p = 0.008). CONCLUSION: The novelty seeking score was low in BMS patients in comparison to the control group. They also had high harm avoidance and low self-directedness tendencies, but these were attributed to the influence of depression.

Effectiveness of low-dose milnacipran for a patient suffering from pain disorder with delusional disorder (somatic type) in the orofacial region.

Glossodynia is chronic pain localized around the tongue, with no perceivable organic abnormalities. In the fields of oral and maxillofacial surgery, it is categorized as an oral psychosomatic disease. In contrast, psychiatric nosology classifies glossodynia as a pain disorder among somatoform disorders, per the DSM-IV. The patient was a 71-year-old woman who developed symptoms of glossodynia, specifically a sore tongue. In the decade before she presented to us, she had had bizarre symptoms of oral cenesthopathy such as the sensation that her teeth had become 'limp and floppy' and that she needles in her mouth. Treatment was attempted using several psychotropic drugs, but no satisfactory response was noted. Because the patient was referred to our outpatient clinic, we tried psychotropic therapy again. Additionally, valproic acid, tandospirone and sertraline were administered (in this order), but the patient still showed no response. However, when sertraline was changed to milnacipran, all symptoms disappeared in a short period. We suggest that a small dose of milnacipran can be effective for controlling oral cenesthopathy as well as glossodynia.

Effectiveness of duloxetine for the treatment of chronic nonorganic orofacial pain.

OBJECTIVE: We examined the pain-relieving effect of duloxetine on chronic nonorganic orofacial pain (burning mouth syndrome and atypical odontalgia), considering the influence of baseline depressive symptoms. METHODS: In this study of 12 weeks, duloxetine was administered in a fixed-flexible dose of 20 to 40 mg/d to 41 patients with burning mouth syndrome and/or atypical odontalgia. Pain was evaluated using the visual analog scale (VAS) at baseline and at 2, 4, 6, 8, 10, and 12 weeks of treatment. Depressive symptoms were assessed using the Hamilton Depression Rating Scale at baseline and at 12 weeks of treatment. RESULTS: We analyzed the data from 29 patients who completed the study. The VAS score at 12 weeks of treatment was significantly lower than that at baseline. The time course of the VAS scores revealed its significant decrease from 2 weeks of treatment compared to the baseline score. To investigate the influence of baseline depressive symptoms on the pain-relieving effect of duloxetine, the subjects were divided into 2 groups based on the Hamilton Depression Rating Scale score on initial consultation: groups with (≥8) and without (≤7) depressive symptoms. Two-way repeated-measures analysis of variance revealed no significant interaction between time and initial presence or absence of depression. An additional intent-to-treat last-observation-carried-forward analysis including dropped-out patients revealed a similar result. CONCLUSION: Duloxetine significantly relieved chronic nonorganic orofacial pain. Its pain-relieving effect appeared from 2 weeks of treatment. Furthermore, the pain-relieving effects of duloxetine similarly appeared regardless of the presence or absence of baseline depressive symptoms.

Pain threshold and pain recovery after experimental stimulation in patients with burning mouth syndrome.

The aim of the present study was to examine pain threshold and pain recovery in patients with burning mouth syndrome (BMS) and matched no-pain controls. Twenty female patients diagnosed with BMS without organic gross changes were enrolled in the study. Twenty control subjects were chosen from age-matched healthy female volunteers. We compared the thermal pain threshold using heat beam dolorimeter on the finger and tongue between patients and controls. Warm (at 50 degrees C for 5 s), cold (at 0 degrees C for 30 s) and mechanical (stimulation by electric tooth brush for 15 s) stimulation was applied to the tongue for both groups. Participants were asked to rate the subjective pain using a visual analogue scale (VAS). Although there was no significant differences between patients and controls in terms of the threshold on the finger, the threshold on the tongue was significantly higher in patients than in controls. We suggest there were peripheral dysfunction at the tongue, and/or central dysfunction in patients with BMS. Among the three types of stimulation, the patients perceived significantly the highest pain from the mechanical stimulation for the first 5 min after the stimulation. Furthermore, when patients with BMS perceived some pain, they continued to complain of the pain longer and more intricately than the controls. This indicates that the pain of the patients is strongly affected not only at a sensory component but also at an affective/motivational component than the controls. However, we should be cautious of simply advancing psychogenic theory in this etiology.