title: Pharmacological treatment for pain in Guillain-Barré syndrome.
abstract: BACKGROUND
  Pain in Guillain-Barré syndrome (GBS) is common, yet it is often under recognised and poorly managed. In recent years, a variety of pharmacological treatment options have been investigated in clinical trials for people with GBS-associated pain.
  
  
  OBJECTIVE
  To assess the efficacy and safety of pharmacological treatments for various pain symptoms associated with GBS, during both the acute and convalescent (three months or more after onset) phases of GBS.
  
  
  METHODS
  On 27 August 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2012, Issue 8) in The Cochrane Library, MEDLINE (January 1966 to August 2012) and EMBASE (January 1980 to August 2012). In addition, we searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform.
  
  
  METHODS
  We included randomised controlled trials (RCTs) and quasi-RCTs in participants with confirmed GBS, with pain assessment as either the primary or secondary outcome. For cross-over trials, an adequate washout period between phases was required for inclusion.
  
  
  METHODS
  Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy and assessed the risk of bias of each study.
  
  
  RESULTS
  Three short-term RCTs, which enrolled 277 randomised participants with acute phase GBS, were included. Risk of bias in the included studies was generally unclear due to insufficient information. None of the included studies reported the primary outcome selected for this review, which was number of patients with self reported pain relief of 50% or greater. One small study investigated seven-day regimens of gabapentin versus placebo. Pain was rated on a scale from 0 (no pain) to 10 (maximum pain). Amongst the 18 participants, significantly lower mean pain scores were found at the endpoint (day 7) in the gabapentin phase compared to the endpoint of the placebo phase (mean difference -3.61, 95% CI -4.12 to -3.10) (very low quality evidence). For adverse events, no significant differences were found in the incidence of nausea (risk ratio (RR) 0.50, 95% CI 0.05 to 5.04) or constipation (RR 0.14, 95% CI 0.01 to 2.54). A second study enrolling 36 participants compared gabapentin, carbamazepine and placebo, all administered over seven days. Participants in the gabapentin group had significantly lower median pain scores on all treatment days in comparison to the placebo and carbamazepine groups (P < 0.05). There were no statistically significant differences in the median pain scores between the carbamazepine and placebo groups from day 1 to day 3, but from day 4 until the end of the study significantly lower median pain scores were noted in the carbamazepine group (P < 0.05) (very low quality evidence). There were no adverse effects of gabapentin or carbamazepine reported other than sedation. One large RCT (223 participants, all also treated with intravenous immunoglobulin), compared a five-day course of methylprednisolone with placebo and found no statistically significant differences in number of participants developing pain (RR 0.89, 95% CI 0.68 to 1.16), number of participants with decreased pain (RR 0.95, 95% CI 0.63 to 1.42) or number of participants with increased pain (RR 0.85, 95% CI 0.52 to 1.41) (low quality evidence). The study did not report whether there were any adverse events.
  
  
  CONCLUSIONS
  While management of pain in GBS is essential and pharmacotherapy is widely accepted as being an important component of treatment, this review does not provide sufficient evidence to support the use of any pharmacological intervention in people with pain in GBS. Although reductions in pain severity were found when comparing gabapentin and carbamazepine with placebo, the evidence was limited and its quality very low. Larger, well-designed RCTs are required to further investigate the efficacy and safety of potential interventions for patients with pain in GBS. Additionally, interventions for pain in the convalescent phase of GBS should be investigated.
authors.affiliation: Department of Geriatric Neurology, Chinese PLA General Hospital, Fuxing Road 28, Beijing, China, 100853.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Lu-Ning
authors.initials: LN
authors.lastname: Wang
authors.forename: Ewan D
authors.initials: ED
authors.lastname: McNicol
mesh_terms: D000588:Amines / Q000009:adverse effects / Q000627:therapeutic use; D000700:Analgesics / Q000009:adverse effects / Q000627:therapeutic use*; D002220:Carbamazepine / Q000009:adverse effects / Q000627:therapeutic use; D003248:Constipation / Q000139:chemically induced; D003509:Cyclohexanecarboxylic Acids / Q000009:adverse effects / Q000627:therapeutic use; D000077206:Gabapentin; D020275:Guillain-Barre Syndrome / Q000150:complications*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008775:Methylprednisolone / Q000627:therapeutic use; D009325:Nausea / Q000139:chemically induced; D010146:Pain / Q000150:complications / Q000188:drug therapy*; D010147:Pain Measurement; D016032:Randomized Controlled Trials as Topic; D005680:gamma-Aminobutyric Acid / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000588:Amines; D000700:Analgesics; D003509:Cyclohexanecarboxylic Acids; D016756:Immunoglobulins, Intravenous; D002220:Carbamazepine; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D008775:Methylprednisolone