title: Efficacy of a paracetamol and caffeine combination in the treatment of the key symptoms of primary dysmenorrhoea.
abstract: OBJECTIVE
  Primary dysmenorrhoea is characterised by pain, cramping and backache at the time of menses. Despite the high prevalence of dysmenorrhoea, few sufficiently powered, placebo-controlled studies have examined the efficacy of over the counter analgesics in this condition. Furthermore, even fewer studies have directly examined the efficacy of analgesics on specific dysmenorrhoea symptoms. Research design and main outcome measures: This was a single-dose, placebo-controlled, double blind, crossover study carried out in 320 women with moderate-to-severe dysmenorrhoea pain. At 2 h following dosing, 1 g paracetamol plus 130 mg caffeine led to significantly greater pain relief compared to 1 g paracetamol alone (p < 0.05), 130 mg caffeine alone (p < 0.01) or placebo (p < 0.01). The combination was also significantly more effective in relieving abdominal cramping and backache compared to the other treatment arms. No major treatment related adverse events were reported during this study.
  
  
  CONCLUSIONS
  When taken at recommended doses, both paracetamol and the combination of paracetamol and caffeine are safe and effective treatments for primary dysmenorrhoea. Consistent with results from other acute pain states, caffeine acts as an analgesic adjuvant and enhances the efficacy of paracetamol.
authors.affiliation: GlaxoSmithKline Consumer Healthcare, St George's Avenue, Weybridge, Surrey, UK. ali@gsk.com <ali@gsk.com>
authors.forename: Z
authors.initials: Z
authors.lastname: Ali
authors.forename: I
authors.initials: I
authors.lastname: Burnett
authors.forename: R
authors.initials: R
authors.lastname: Eccles
authors.forename: M
authors.initials: M
authors.lastname: North
authors.forename: M
authors.initials: M
authors.lastname: Jawad
authors.forename: S
authors.initials: S
authors.lastname: Jawad
authors.forename: G
authors.initials: G
authors.lastname: Clarke
authors.forename: I
authors.initials: I
authors.lastname: Milsom
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage* / Q000009:adverse effects; D000293:Adolescent; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000009:adverse effects; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000009:adverse effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004412:Dysmenorrhea / Q000188:drug therapy*; D005260:Female; D006801:Humans; D010919:Placebos; D016896:Treatment Outcome
chemical_list: D018712:Analgesics, Non-Narcotic; D000697:Central Nervous System Stimulants; D010919:Placebos; D000082:Acetaminophen; D002110:Caffeine