Abstract and Key Words
Objective
To evaluate long-term continuation rates of daily preventative medications for
chronic daily headache (CDH).
Background
Many medications have been utilized in an effort to decrease severity/frequency of
CDH. Short-term (less than 6 months) studies often demonstrate success at
preventing CDH. However, the long-term success of these medications for CDH has
not been demonstrated.
Methods
This retrospective study evaluated continuation rates (at least 6 months) for
different classes of CDH preventatives. 646 moderate or severe CDH patients were
evaluated. Among those who discontinued the medications, a determination was made
as to whether the medication was stopped due to a lack of efficacy, versus the
presence of adverse events.
Results
Of those 646 patients, only 46% stated that they remained on a preventative for 6
months or longer. 36% of the patients continued (more than 6 months) on selective
serotonin reuptake inhibitors (SSRI’s). 35% continued long-term on sodium valproate
(Depakote), while 31% continued on tricyclic antidepressants. Only 22% of patients
remained on B-blockers long-term.
Lack of efficacy was cited as the primary reason for discontinuation. Approximately
1/5 of patients discontinued the preventative primarily due to adverse events.
Conclusion
The majority (54%) of patients do not obtain adequate long-term relief from CDH
preventative medications. SSRI’s and sodium valproate were the most successful
medications for preventing CDH.
Key Words:
Chronic Daily Headache, Preventative Medications
Abbreviation:
CDH - Chronic Daily Headache, SSRI – Selective Serotonin Reuptake
Inhibitor, NSAID – Nonsteroidal Anti-Inflammatory Drug
Introduction
Chronic daily headache (CDH) is a common problem, affecting approximately 3 to 4%
of the population.(1) CDH poses a significant therapeutic challenge to both
physician and patient.
For those patients with moderate or severe CDH, preventative medications are often
utilized in an effort to both limit analgesics and decrease headache frequency
and/or severity. The primary first-line preventatives include antidepressants
(primarily selective serotonin reuptake inhibitors (SSRI’s) and tricyclics) and
sodium valproate.(2) Antidepressants have been an attractive choice in those with
comorbid depression and anxiety. Tricyclic antidepressants have been noted to have
enhanced efficacy over SSRI’s, but are not as well tolerated. The anticonvulsant
sodium valproate has emerged as an effective drug for use in CDH.(3) It can be
particularly useful for patients with comorbid seizure disorders, bipolar disorder,
and even anxiety.
Other medications that have shown some benefit in CDH prophylaxis include
B-blockers, calcium channel blockers, NSAID’s, gabapentin, and muscle relaxants.(2)
Unfortunately, due to a lack of efficacy, and/or the presence of side effects, the
preventative medications are not always a useful long-term solution. The failure
of the preventatives often frustrates physicians and patients. The purpose of this
paper was to retrospectively evaluate preventative medications in a large number of
chronic daily headache patients.
Materials and Methods
Primary Objective and End Point:
This study was a retrospective investigation of the continuation rates for
different classes of headache preventative medications. Overall headache relief,
defined as at least 50% improvement in headache frequency and/or severity, served
as the primary end point.
Inclusion Criteria:
Men or women, at least 17 years of age, diagnosis of CDH or transformed migraine
(TM) according to the criteria established by Silberstein et al,(4) moderate or
severe intensity of the CDH, and current or past use of at least two classes of
daily preventative medications for at least six months.
Exclusion Criteria:
Continuous analgesic rebound headache that had not been resolved, non-compliance
with the daily preventative medications, evidence of renal insufficiency or
impaired liver function upon routine laboratory evaluations, or the presence of any
medical condition that could interfere with the absorption, metabolism, and
excretion of any of the preventative medications.
Design:
Six hundred forty six moderate or severe chronic daily headache patients, ages 17
to 74, were evaluated. They were all long-term patients at the Robbins Headache
Clinic, a private clinic with both physician and self-referred patients. Evaluation
was accomplished via chart review and patient interviews conducted by the treating
neurologist. Four main classes of preventative medications were evaluated: SSRI’s
sodium valproate, tricyclic antidepressants, and B-blockers. Patients included in
the study were assessed to determine which preventative medications they remained
on long-term. A determination was also made as to which preventative medications
were discontinued due to a lack of efficacy, versus the presence of side effects.
Statistical Analysis – Patient data was tabulated and analyzed suing SPSS Sigma Stat 2.03. Chi-square analysis was performed on the tabulated data. To assure accuracy, a power analysis of the Chi-square was utilized, using an alpha value of 0.05.
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