In their article, Pini et al. (1) raise important
issues about the treatment of chronic daily headache (CDH)
associated with analgesic overuse. They provide observational
data on a cohort of CDH patients over 4 years, comparing
outcomes in subjects with analgesic overuse who became non-over-users,
those who fail to successfully detoxify themselves over 4 years
despite treatment, and control subjects who were never overusing
analgesics.
Their results significantly challenge what has been the standard
teaching in many clinics. The first level of analysis was
consistent with our beliefs. The duration of CDH and the amount
of overused medicine predicted a failure to remain detoxified.
As in previous studies, combination medication overuse was
associated with recidivism. These findings, again, support the
concept that medication overuse is a factor in the evolution of
daily headache into more frequent and more refractory headache.
Surprising was the low levels of maintained detoxification, 36/90
patients contacted at follow-up in contrast to most previous
studies. Also distressing is the persistence of high headache
severity index despite successful detoxification. This contrasts
with previous studies, which suggest that successful
detoxification is associated with improvement in headache
frequency, intensity and duration.
Quality of life, as might be expected, was better in non-overusing
controls than in prior over-users. Most surprising was the poor
quality of life in patients who were successfully detoxified.
The authors suggest that daily analgesics improve quality of
life, independent of headache severity. There are, however,
other potential explanations. First and foremost, quality of
life may originally have been worse in ex-over-users. This could
have been part of the motivation to discontinue analgesics. This
is a very likely explanation as quality of life was not measured
at baseline. Secondly, quality of life was better in the control
group of daily headache patients without analgesic overuse who had
a shorter duration of illness. Thus, duration of illness may
affect both quality of life and need for treatment. Other
features of the ex-over-user group (not measured), such as
pre-treatment psychiatric comorbidity, could affect both quality
of life as well as the ability to be detoxified. This concept is
consistent with the observation that quality of life improved in
subjects with migraine and worsened in those with chronic tension
headache.
There could be errors of under-ascertainment. Subjects who
continue to overuse may be reluctant to inform their physician.
Warner has recently reported that only one of 29 of his patients
who remained fully detoxified for 1 year failed to achieve the
goal of six consecutive headache-free days. Although the
follow-up period is less in this study than in the study by
Luigi-Alberto, and his outcome measures differ, these findings
suggest the outcome of detoxification is not so bleak. In most
studies the positive results are >50% at 3-60 months follow-up.
It has not been proven that quality of life is better in
persistent over-users. If this were so, how could it be?
Could analgesic overuse benefit depression or anxiety, or some
other factor? This will require careful study, describing
pre-treatment patient characteristics, treatments received and
consecutive quality of life measurements. Successfully
detoxified patients, with comorbid depression and anxiety,
not getting specific treatment, could add to the low quality of
life scores. How firmly should we urge our patients with
persistent daily headache after analgesic overuse to abstain
from analgesic overuse? The standard of care is still
abstention. There may, however, be a group of particularly
refractory patients for whom daily analgesic use is appropriate.
The decision to condone overuse cannot be taken lightly.
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