Buprenorphine may be effective for treatment of paramyotonia congenita.
Muscle Nerve
; 64(1): 95-99, 2021 07.
Article
em En
| MEDLINE
| ID: mdl-33835497
ABSTRACT
INTRODUCTION/AIMS:
Paramyotonia congenita (PMC) is a skeletal muscle sodium channelopathy characterized by paradoxical myotonia, cold sensitivity, and exercise/cold-induced paralysis. Treatment with sodium-channel-blocking antiarrhythmic agents may expose patients to a risk of arrhythmia or may be poorly tolerated or ineffective. In this study we explored the effectiveness of non-antiarrhythmic sodium-channel blockers in two patients with PMC.METHODS:
Earlier treatment with mexiletine was discontinued for gastrointestinal side effects in one of the patients and lack of clinical benefit in the other. One patient received lacosamide, ranolazine, and buprenorphine, and the other was given buprenorphine only. Drug efficacy was assessed by clinical scores, timed tests, and by long and short exercise tests.RESULTS:
In both patients, buprenorphine improved pain scores by at least 50%, stiffness and weakness levels, and handgrip/eyelid-opening times. The fall in compound muscle action potential (CMAP) during short exercise normalized in both patients at baseline, and improved after cooling. During long exercise, one patient showed an earlier recovery of CMAP, and the other patient had a less severe decrease (<60%). With buprenorphine, the fall in CMAP induced by cooling normalized in one patient (from -72% to -4%) and improved (from -49% to -37%) in the other patient.DISCUSSION:
Buprenorphine showed promising results for the treatment of exercise-induced paralysis and cold intolerance in the two patients assessed. The exercise test may be useful for quantitative assessment of treatment response. Further studies on a larger number of patients, under carefully controlled conditions, should be considered to address the effectiveness and long-term tolerability of this therapeutic option.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Buprenorfina
/
Transtornos Miotônicos
/
Analgésicos Opioides
Limite:
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Muscle Nerve
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Itália