Myofascial Pain: An Open Study on the Pharmacotherapeutic Response to Stepped Treatment with Tricyclic Antidepressants and Gabapentin

Abstract

Aims: To evaluate, in an open trial, the pharmacotherapeutic efficacy of tricyclic antidepressant (TCA) drugs and gabapentin in patients with persistent myofascial pain and to identify patient and pain characteristics that may predict treatment outcome. Methods: A stepped pharmacotherapeutic protocol was employed. All 42 patients having persistent facial pain with tenderness of regional muscles were first prescribed amitriptyline, but those with side effects were subsequently transferred to nortriptyline. In patients where no response to TCAs was observed, gabapentin was initiated. Outcome was assessed by employing prospective diaries recording pain intensity measured with an 11-point (0-10) verbal pain scale (VPS). Individual characteristics in these patients and their influence on drug response and outcome were analyzed; specifically, patients treated with TCAs were compared with those subsequently treated with gabapentin. Chisquare and t tests were used to analyze the data. Results: A total of 23 patients responded to TCAs and continued on this regimen, while 19 were resistant to TCAs and were subsequently treated with gabapentin. Their mean (± SD) VPS score at baseline was 6.5 ± 1.9 on an 11-point scale. In TCA-treated patients, 43% showed ≥ 50% reduction in pain intensity. This was achieved with a mean amitriptyline dose of 16 ± 1. 1 mg/d and a mean nortriptyline dose of 25 ± 2. 1 mg/d. Patients who did not respond to TCAs were characterized by a significantly higher age, more comorbid medical illness, and evidence of more regional pain spread (P < .05). In spite of not responding to TCAs, 36.8% of this group showed ≥ 50% reduction in pain intensity following gabapentin therapy at a mean daily dose of 973.7 ± 68.8 mg. Overall, a stepped approach employing TCAs and gabapentin resulted in 54.8% of all treated patients reporting improvements of ≥ 50% in VPS scores. Conclusion: This study has demonstrated the good pharmacotherapeutic response of persistent myofascial pain, even in more severe cases. Not being a randomized controlled trial, the results may be biased and should be interpreted with caution. Patients who do not respond to TCAs may be a distinct subgroup and this needs further investigation. The results also suggest that gabapentin, at a lower dose than previously reported, is a good alternative in TCA-resistant patients.

Non-invasive therapies for management of temporomandibular disorders: a systematic review

“…A millimeter ruler was used in 10 (29%) studies 15,24,25,31,33,36,46,56,57,63 and a caliper in 4 (11%) 1,27,52,58 . The remaining 6 (17%) studies did not describe the secondary outcome 10,44,45,49,53,60 . Significant improvement in mouth opening was described only in 13 (37%) studies using LLLT (17%) 15,20,24,56,57,64 , acupuncture (6%) 36,62 , MT (6%) 25,52 , TENS (3%) 24 , OMT (3%) 54 , and benzodiazepine (3%) 59 .…”

“…Non-invasive therapies have been recommended as first choice treatment for TMD arousing the interest of many authors who attempted to find a gold standard treatment protocol 6,7 . Despite the wide use of these therapies in clinical practice, the efficacy of most of them in TMD is still controversial, probably due to the variety of parameters and protocols 7,60,65 . Our results demonstrated that non-invasive therapies presented a low positive response, found in only 43% of the studies.…”

“…Besides that, our results showed only one study 63 that considered the psychosocial aspects and their influence on primary and secondary outcomes. TMD treatment has been considered a challenge because of its multifactorial origin, including a complex interaction among physical, behavioral, social, and psychological factors 49,52,60 . Based on these aspects, the analysis of the impact of treatment strategies based on the perspective of quality of life has been currently suggested.…”

“…Of all the included studies, 13 (37%) used OS 1,10,16,36,[46][47][48][49][50][51][52][53][54] , 12 (34%), OE/BE 1,5,16,25,27,31,47,48,[50][51][52]54 , 12 (34%), LLLT 2,5,15,20,24,44,55,[57][58][59][60] , 7 (20%), MT 5,25,27,47,52,54,61 , 4 (11%), acupuncture 33,36,46,62 , 3 (9%), NSAIDs 10,44,53 , 3 (9%), TENS 22,24,…”

The first medications in my TMD toolbox

“…Nortriptyline, which has no active metabolites, may be used as an alternative [37,38]. Thankfully, doses used in TMD (e.g., 10-30 mg amitriptyline, 25 mg nortriptyline) [39] are well below the 75 mg threshold for anticipated cardiotoxicity [40].…”