The Effect of Single-dose Propofol Injection on Pain and Quality of Life in Chronic Daily Headache: a Randomized Double-blind Controlled Trial

Chronic daily headache (CDH) is a common and extremely disabling pain syndrome with a recent estimated point prevalence of 2.98% of the general population1 Other studies estimate a prevalence of 4.1% and 4.7% with a higher prevalence in women of 9%.2,3 The condition is disabling and is a major cause of loss of function and work capacity resulting in significant personal and national economic loss4

Therapeutic options for treating chronic headache disorders are legion and diverse and there is a steady stream of publications advocating novel therapies. Pharmacological options that have been advocated include: sodium valproate, olanzapine, tricyclic and Selective Serotonin Reuptake Inhibitor antidepressants, tizanidine, butalbital, nefazodone, baclofen, prochlorperazine, intravenous lignocaine, dihydroergotamine, opioids, monoamine oxidase inhibitors, triptans, botulinum toxin, cryotherapy and analgesic withdrawal5-20 There is much debate as to why headache treatments fail and it is proposed that the choice of an inappropriate agent is a significant reason in some patients21

On the basis of a small number of studies intravenous propofol has now been advocated for the treatment of chronic daily headache22-24 It seems fair to conclude that the existing strife to promote propofol as an effective intervention for treating CDH in the absence of a randomized controlled trial merely reflects the lack of a single good treatment option for this condition. It is, furthermore, reasonable to speculate that the beneficial effect seen with propofol is a placebo response. Krusz et al reports the effects of subanesthetic doses of intravenous propofol on chronic migraine in a cohort of 77 subjects in an open-label study22 Propofol was administered by intermittent boluses; the average dose used was 110mg. It is reported that 63 out of 77 patients reported complete abolition of their headache with an average time of 20 - 30 minutes of propofol treatment. The range of propofol doses used is however not clearly stated and there was no assessment of the intervention beyond 24 hours. In this study lidocaine was mixed with propofol to reduce the pain of injection but it could not be said with any certainty that lidocaine itself has no effect on headache.

Mendes et al retrospectively reports 21 independent treatments of propofol in 18 patients suffering primary and secondary chronic daily headache over a 1 year period 23 Subanesthetic doses of propofol were administered by intermittent intravenous boluses 20 - 30mg every 3 to 5 minutes (range 60 - 380 mg). 6 patients reported complete relief of pain with the treatment, 1 patient had no pain relief; on average patients reported a 58.92% decrease in pain using a 0 - 10 scale. It is reported that 8 patients' headache cycles were broken when followed up several days later but no information is available on the longer term impact of these interventions. In these two studies there appears to have been good tolerance of propofol and no significant adverse events.

Drummond - Lewis reports 2 hospitalized patients with refractory migraine who were treated with anesthetic bolus doses of propofol (0.5 - 1mg / kg) with reported success 24. The authors comment there is uncertainty as to the most effective dose of propofol for this treatment.