title: WITHDRAWN. Anticonvulsant drugs for acute and chronic pain.
abstract: BACKGROUND
  Anticonvulsant drugs have been used in the management of pain since the 1960s. The clinical impression is that they are useful for chronic neuropathic pain, especially when the pain is lancinating or burning. Readers are referred to reviews of carbamazepine and gabapentin in T he Cochrane Library which replace the information on those drugs in this review. Other drugs remain unchanged at present in this review
  
  
  OBJECTIVE
  To evaluate the analgesic effectiveness and adverse effects of anticonvulsant drugs for pain management in clinical practice . Migraine and headache studies are excluded in this revision.
  
  
  METHODS
  Randomised trials of anticonvulsants in acute, chronic or cancer pain were identified by MEDLINE (1966-1999), EMBASE (1994-1999), SIGLE (1980 to 1999) and the Cochrane Controlled Trials Register (CENTRAL/CCTR) (The Cochrane Library Issue 3, 1999). In addition, 41 medical journals were hand searched. Additional reports were identified from the reference list of the retrieved papers, and by contacting investigators. Date of most recent search: September 1999.
  
  
  METHODS
  Randomised trials reporting the analgesic effects of anticonvulsant drugs in patients, with subjective pain assessment as either the primary or a secondary outcome.
  
  
  METHODS
  Data were extracted by two independent review authors, and trials were quality scored. Numbers-needed-to-treat (NNTs) were calculated from dichotomous data for effectiveness, adverse effects and drug-related study withdrawal, for individual studies and for pooled data.
  
  
  RESULTS
  Twenty-three trials of six anticonvulsants were considered eligible (1074 patients).The only placebo-controlled study in acute pain found no analgesic effect of sodium valproate.Three placebo-controlled studies of carbamazepine in trigeminal neuralgia had a combined NNT (95% confidence interval (CI)) for effectiveness of 2.5 (CI 2.0 to 3.4). A single placebo-controlled trial of gabapentin in post-herpetic neuralgia had an NNT of 3.2 (CI 2.4 to 5.0). For diabetic neuropathy NNTs for effectiveness were as follows: (one RCT for each drug) carbamazepine 2.3 (CI 1.6 to 3.8), gabapentin 3.8 (CI 2.4 to 8.7) and phenytoin 2.1 (CI 1.5 to 3.6).Numbers-needed-to-harm (NNHs) were calculated where possible by combining studies for each drug entity irrespective of the condition treated. The results were, for minor harm, carbamazepine 3.7 (CI 2.4 to 7.8), gabapentin 2.5 (CI 2.0 to 3.2), phenytoin 3.2 (CI 2.1 to 6.3). NNHs for major harm were not statistically significant for any drug compared with placebo.Phenytoin had no effect in irritable bowel syndrome, and carbamazepine little effect in post-stroke pain. Clonazepam was effective in one study of temporomandibular joint dysfunction.
  
  
  CONCLUSIONS
  Although anticonvulsants are used widely in chronic pain surprisingly few trials show analgesic effectiveness. Only one study identified considered cancer pain. There is no evidence that anticonvulsants are effective for acute pain. In chronic pain syndromes other than trigeminal neuralgia, anticonvulsants should be withheld until other interventions have been tried. While gabapentin is increasingly being used for neuropathic pain the evidence would suggest that it is not superior to carbamazepine.
authors.affiliation: UK Cochrane Centre, National Institute for Health Research, Summertown Pavilion, Middle Way, Oxford, UK, OX2 7LG.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Wiffen
authors.forename: Sally
authors.initials: S
authors.lastname: Collins
authors.forename: Henry J
authors.initials: HJ
authors.lastname: McQuay
authors.forename: Dawn
authors.initials: D
authors.lastname: Carroll
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jadad
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Moore
mesh_terms: D000208:Acute Disease; D000588:Amines / Q000627:therapeutic use; D000927:Anticonvulsants / Q000627:therapeutic use*; D002908:Chronic Disease; D018849:Controlled Clinical Trials as Topic; D003509:Cyclohexanecarboxylic Acids / Q000627:therapeutic use; D006801:Humans; D010146:Pain / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use
chemical_list: D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid