title: Efficacy of memantine in the treatment of fibromyalgia: A double-blind, randomised, controlled trial with 6-month follow-up.
abstract: Fibromyalgia (FM) is a prevalent and disabling chronic disease. Recent studies have found elevated levels of glutamate in several brain regions, leading to hypotheses about the usefulness of glutamate-blocking drugs such as memantine in the treatment of FM. The aim of this study was to evaluate the efficacy of memantine in the treatment of pain and other clinical variables (global function, clinical impression, depression, anxiety, quality of life) in FM patients. A double-blind, parallel randomised controlled trial was developed. A total of 63 patients diagnosed with FM were recruited from primary health care centres in Zaragoza, Spain. Memantine was administered at doses of 20mg/d after 1 month of titration. Assessments were carried out at baseline, posttreatment, and 3- and 6-month follow-up. Compared with a placebo group, memantine significantly decreased ratings on a pain visual analogue scale (Cohen's d=1.43 at 6 months) and pain measured with a sphygmomanometer (d=1.05). All other secondary outcomes except anxiety also improved, with moderate-to-large effect sizes at 6 months. Compared with placebo, the absolute risk reduction obtained with memantine was 16.13% (95% confidence interval=2.0% to 32.6%), and the number needed to treat was 6.2 (95% confidence interval=3 to 47). Tolerance was good, with dizziness (8 patients) and headache (4 patients) being the most frequent side effects of memantine. Although additional studies with larger sample sizes and longer follow-up times are needed, this study provides preliminary evidence of the utility of memantine for the treatment of FM.
authors.affiliation: Department of Psychology and Sociology, University of Zaragoza, Spain Preventative Activities and Health Promotion Network (REDIAPP) (RD06/0018), Instituto Aragonés de Ciencias de la Salud (IACS), Aragón, Spain Unidad Epidemiología Clínica, Hospital 12 de Octubre, Autonomous University of Madrid, CIBER Epidemiology and Public Health, Madrid, Spain Department of Radiology, Hospital Quirón, Zaragoza, Spain Primary Health Center Arrabal, Zaragoza, Spain Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), University of Balearic Islands, Palma de Mallorca, Spain Department of Psychiatry, Miguel Servet University Hospital, Zaragoza, Spain.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Olivan-Blázquez
authors.forename: Paola
authors.initials: P
authors.lastname: Herrera-Mercadal
authors.forename: Marta
authors.initials: M
authors.lastname: Puebla-Guedea
authors.forename: Mari-Cruz
authors.initials: MC
authors.lastname: Pérez-Yus
authors.forename: Eva
authors.initials: E
authors.lastname: Andrés
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fayed
authors.forename: Yolanda
authors.initials: Y
authors.lastname: López-Del-Hoyo
authors.forename: Rosa
authors.initials: R
authors.lastname: Magallon
authors.forename: Miquel
authors.initials: M
authors.lastname: Roca
authors.forename: Javier
authors.initials: J
authors.lastname: Garcia-Campayo
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000188:drug therapy / Q000209:etiology; D004311:Double-Blind Method; D018691:Excitatory Amino Acid Antagonists / Q000627:therapeutic use*; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000188:drug therapy*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008559:Memantine / Q000627:therapeutic use*; D008875:Middle Aged; D019964:Mood Disorders / Q000188:drug therapy / Q000209:etiology; D009483:Neuropsychological Tests; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D011569:Psychiatric Status Rating Scales; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D018691:Excitatory Amino Acid Antagonists; D008559:Memantine
keywords: Chronic pain; Fibromyalgia; Memantine; Randomised controlled trial