This study aimed to determine the safety and efficacy of
tramadol 37.5 mg/
acetaminophen 325 mg combination
tablets (Ultracet®) in patients with
ankylosing spondylitis (AS). This was a 12-week, randomized, double-blind, placebo-controlled study. Sixty patients with active AS according to the Modified New York Criteria were enrolled. Active disease was defined by Bath
Ankylosing Spondylitis Disease Activity Index (BASDAI) for more than 3 at randomization. Subjects were randomized equally into two groups: the treatment group received
aceclofenac plus Ultracet® one
tablet twice a day, and the control group received
aceclofenac plus placebo for 12 weeks. The primary endpoint was a difference of Assessment in
Ankylosing Spondylitis (ASAS20) response criteria between two groups at week 12. At week 12, ASAS20 was achieved by 53.3 % of the
aceclofenac plus
Ultracet group and 31 % of the
aceclofenac alone group (p = 0.047). For the
pain visual analogue scale at week 12, there was a reduction of 45.6 % in
aceclofenac plus
Ultracet group and 25.7 % in the
aceclofenac alone group (p = 0.087). There was no statistically significant difference between two groups in BASDAI, Bath
Ankylosing Spondylitis Functional Index, Bath
Ankylosing Spondylitis Global Index, Physician Global Assessment, spinal mobility, ESR,
hs-CRP, and
Ankylosing Spondylitis Quality of Life Questionnaire. A slight increase in total adverse events was noted with
dizziness (7.5 vs 1.5 %),
vertigo (4.5 vs 1.5 %), and
nausea/
vomiting (6 vs 0 %) in the
Ultracet arm compared to placebo. The
tramadol 37.5 mg/
acetaminophen 325 mg combination
tablet (Ultracet®) might has additional effect to nonsteroidal anti-inflammatory drugs in the treatment of patients with
ankylosing spondylitis. It showed marginal benefit in
pain and disease activity. However, a slight increase in minor adverse events was noted.