Debilitating pain
Patients were randomly assigned to receive oral prednisone (n = 53) or placebo (n = 56). The study groups were matched with respect to demographic and clinical characteristics. Prednisone was initiated at 100 mg/d for 5 days and was then tapered by 20 mg every 3 days in the active-treatment group. All patients also received oral verapamil at a starting dose of 40 mg three times per day. The dose was increased every 3 days by 40 mg to a maximum of 360 mg/d.
All participants received pantoprazole 20 mg to prevent the gastric side effects of prednisone. An attack was defined as a unilateral headache of moderate to severe intensity. The study lasted 28 days.
The study’s primary outcome was the mean number of cluster headache attacks during the first week of treatment with prednisone versus placebo.
The mean number of attacks during the first week of treatment was 7.1 in the prednisone group and 9.5 in the placebo group, for a difference of –2.4 attacks (95% confidence interval, –4.8 to –0.03; P = .002). “This might not sound like much,” but reducing the number of daily attacks from, say, eight to six “really makes a difference because the attacks are so painful,” said Dr. Obermann.
The prednisone group also came out on top for a number secondary outcomes. After the first 7 days, attacks ceased in 35% of the prednisone group versus 7% in the placebo group.
‘Clear evidence’ of efficacy
About 49% of patients who took prednisone reported a reduction of at least 50% in attack frequency at day 7. By comparison, 15% of patients who received placebo reported such a reduction. The number of cluster attacks at day 28 was less in the prednisone group than in the patients who received placebo.
With respect to treatment effect, the difference between prednisone and placebo gradually lessened over time “in parallel to the verapamil dose reaching its therapeutic effect,” the investigators noted. “Therefore, attack frequency reduction slowly converged between groups,” they added.
The study results provide “clear evidence” and should reassure clinicians that short-term prednisone early in a cluster headache attack is effective, said Dr. Obermann.
Adverse events, which included headache, palpitations, dizziness, and nausea, were as expected and were similar in the two groups. There were only two severe adverse events, both of which occurred in participants in the placebo group.
Dr. Obermann said the investigators were surprised that so many patients in the study were taking analgesics. “Analgesics don’t work in cluster headache; they just don’t work in this kind of pain.”
He noted that prednisone exposure of study patients spanned only 19 days and amounted to only 1,100 mg, which he believes is safe.
The prednisone dose used in the study is “what most clinicians use in clinical practice,” although there have been reports of success using 500 mg of IV prednisone over 5 days, said Dr. Obermann. He added that it would be “interesting to see if 50 mg would be just as good” as a starting dose.
Potential limitations of the study include the fact that the majority of participants were White, so the findings may not be generalizable to other populations.