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Tension-type headache 385
superior to placebo for TH relief, although there appears little reason to use
these drugs for single-dose therapy in the ED. 5
Compared with migraine headache, TH is less likely associated with nausea
and an inability to tolerate oral analgesia. Therefore, the need to provide
injectable NSAIDs is less important, but parenteral agents such as ketorolac
and metamizol (not available in the USA because of potential bone marrow
suppression) have been found to outperform placebo. 7,12
There are conflicting data on the question of whether NSAIDs or acetaminophen
(paracetamol) provide better TH relief. Two trials have found equivalence
between acetaminophen (1000 mg PO) and aspirin (1000 mg PO) or
naproxen (375 mg PO). 9,13 Other studies report mixed results from comparison
of acetaminophen (1000 mg PO) with ketoprofen (25 mg PO); in one
trial, the agents performed equally and in the other the NSAID was superior.
8,14 Some of the inconsistency in the results may reflect the time of
assessment of the pain relief endpoint. There is suggestion that NSAIDs
such as ibuprofen (400 mg PO) provide faster (although not necessarily
more profound) TH relief than acetaminophen. 15,16
Overall, it appears unlikely that there are clinically important efficacy
differences between individual NSAIDs, or between the NSAIDs and acetaminophen.
These agents should be tried on a case-by-case basis, with the
clinician maintaining therapeutic flexibility (an individual patient may
respond differently to different agents in the same class).
The “tension”-type pain of TH is sometimes treated with benzodiazepines.
However, a multicenter RCT of TH patients could detect no overall
benefit from adding a benzodiazepine (etizolam, 0.5 mg PO) to NSAID
monotherapy (mefenamic acid, 250 mg PO). 17
Muscle relaxants such as cyclobenzaprine, chlormezanone, and tizanidine
have been investigated for TH, but the existing evidence does not
support their use in the ED. 18–20
The anti-dopaminergic effects of chlorpromazine (0.1 mg/kg IV) probably
mediate this agent’s reported effectiveness in relieving TH pain, but side
effects limit broad use of this agent. 21
Some drugs, such as mirtazapine, have promise for prophylaxis of chronic
TH but there is no ED role for these agents. 22,23 Other drugs reportedly useful