Is any one analgesic superior for episodic tension-type headache? This systematic review suggests good tolerance of any given agent may be the deciding factor

Journal of Family Practice, Dec, 2006 by Arianne P. Verhagen, Leonie Damen, Marjolein Y. Berger, Jan Passchier, Vivian Merljin, Bart W. Koes

Practice recommendation

* Though all non-narcotic analgesics have equivalent efficacy against tension-type headache, ibuprofen's generally favorable side-effect profile makes it a reasonable first choice.

Whereas quantitative and qualitative analyses of 41 randomized controlled trials (RCTs) strongly suggests that all types of NSAIDs are more effective than placebo (>50% pain relief) against an acute episode of tension-type headache (TTH), the evidence also shows that no single nonsteroidal anti-inflammatory drug (NSAID) is more effective than another in this setting.

How, then, to choose an NSAID? Many of the 41 articles we reviewed reported on the side effects of NSAIDs. No clear differences were reported in the number of side effects between the NSAIDs and placebo. However, differences were found among the types of NSAIDs. Our results agree with those found by Henry et al, (1) who concluded from their meta-analysis that ibuprofen, compared with other NSAIDs, had the lowest relative risk of serious gastrointestinal complications. Given the lack of important differences in efficacy among NSAIDs for relieving an acute episode of TTH, using the most effective dose of a drug that is well tolerated by a patient is a reasonable basis for selection. Ibuprofen, therefore, generally may be advocated.

When acetaminophen is preferred. Our results suggest NSAIDs might be more effective than acetaminophen for TTH. However, because NSAIDs are allergenic for some people, and they must not be used in association with anticoagulants, (2) acetaminophen might be an alternative in these situations. When giving acetaminophen, the dose of the medication might be important due to a possible dose-response relationship.

Why this review was needed

Tension-type headache, also known as tension headache or muscle contraction headache, is the most commonly experienced type of headache (see Episodic tension-type headache). Population-based studies suggest prevalence rates of 35% to 40% in adults. (3-5)

Persons experiencing an acute episode of TTH most often self-treat with mild, non-narcotic analgesics for initial pain relief. Studies have suggested that acetaminophen and NSAIDs like aspirin, ibuprofen, naproxen, and ketoprofen are effective in reducing headache symptoms. But a variety of drugs, dosages, and combinations have been described. No systematic review has, until now, described the efficacy and tolerability of analgesics for the treatment of acute episodes of TTH. Good quality-controlled trials and a systematic review form the basis for evidence-based treatment guidelines, which provide a basis for the individual patient.

We aimed to describe and assess the data from RCTs concerning the efficacy and tolerability of analgesics for the treatment of acute episodes of TTH in adult patients. Details of our Methods and Results follow.

* Methods

Search strategy

Medline and EMBASE were searched from inception to January 2005 using the terms tension-type headache, tension headache, stress headache, or muscle contraction headache together with the search strategy for identifying RCTs described by Robinson and Dickerson. (6) The Cochrane Controlled Trials Register was searched using the words tension headache or tension-type headache or muscle contraction headache. Additional strategies for identifying trials included searching the reference lists of review articles and included studies.

Study selection

Only RCTs including analgesic medicine used in the treatment or management of TTH conducted among adult patients (aged 18 years or older), with reasonable criteria designed to distinguish TTH from migraine, were selected for our review. The use of a specific set of diagnostic criteria (eg, IHS 1988 and Ad Hoc 1962) (7,8) was not required, but TTH diagnoses had to be based on at least some of the distinctive features of TTH--eg, bilateral in location, no nausea or vomiting, mild or moderate intensity, or no exacerbation by exercise.

Main outcome measures were pain relief or recovery over 2 to 6 hours.

Two authors (LD, AV) independently screened titles and abstracts of identified studies for eligibility. All potentially relevant studies were retrieved as full papers and then again independently reviewed by 2 authors (LD, AV). Disagreements were resolved through consensus where possible, or by arbitration with a third author (MB). Crossover designs often presented data from treatment groups, as if the trial was a parallel group trial. The results from these studies were excluded from data-analysis if no results from both arms were presented or a binary correlation coefficient was available. (9)

Methodological quality and data extraction

Two authors (LD with MB, BK, or AV) independently rated the methodological quality of the included trials using the Delphi list. (10) The Delphi list is a generic criteria list developed by international consensus and consists of the following 9 items: 1) randomization; 2) adequate allocation concealment; 3) groups similar at baseline; 4) specification of eligibility criteria; 5) blinding of outcome assessor; 6) blinding of care provider; 7) blinding of patient; 8) presentation of point estimates and measures of variability; 9) intention-to-treat-analysis. One extra item was added: 10) withdrawal or dropout rate unlikely to cause bias. All selected methodological criteria were scored as yes (= 1), no (= 0) or don't know (= 0). A quality score of a trial was computed by counting the number of positive scores, with equal weights applied on all items. In case of a disagreement between the 2 authors, consensus was used to resolve disagreement. When consensus could not be reached, a third author made the final decision (MB or AV).