Treatment with the antidepressant venlafaxine (brand name Effexor XR) reduces pain, muscle stiffness, and interference in daily life in women with fibromyalgia who don’t have depressive disorder, according to researchers.
The study, “The Effects of Venlafaxine vs Gabapeptine in Fibromyalgia,” will be presented in a poster session titled General Neurology, at the 2018 American Academy of Neurology (ANN) Annual Meeting on April 26. The meeting is April 21-27 in Los Angeles.
Fibromyalgia causes widespread pain and increased pain sensitivity, as well as fatigue, muscle stiffness, sleep disturbance, and depression.
Patients with fibromyalgia have few effective treatments to choose from. Two options are the antiepileptic medication gabapentin (Neurontin), and venlafaxine, a selective serotonin and norepinephrine reuptake inhibitor (SNRIs) antidepressant.
Researchers compared the effects of venlafaxine with gabapentin 90 in fibromyalgia patients without depressive disorder.
The study included 163 ambulatory patients (mean age of 51) with primary fibromyalgia, characterized by diffuse chronic pain with unknown cause. Researchers evaluated the Fibromyalgia Impact Questionnaire (FIQ)‘s total score (0-80 range, with 0 indicating no impact) and pain score (0-10).
They also assessed the mean tender point pain threshold, which represents a patient’s pain threshold when force is applied; number of tender points, which are areas of muscle painful upon palpation; FIQ fatigue score; and tiredness.
Results revealed that, compared to gabapentin, treatment with venlafaxine led to greater improvements in the FIQ total score, but not in the pain score.
Patients treated with venlafaxine also saw greater decreases in pain severity and functional interference from pain – activity, mood, walking ability, normal work, relations with others, sleep, and life enjoyment – as assessed with the Brief Pain Inventory, number of tender points, FIQ stiffness score, and mean tender point pain threshold.
The benefits of venlafaxine over gabapentin were significant in women – 42 received venlafaxine, and 59 were given gabapentin – but not in men. The improvements in women were independent of the effect on mood or anxiety.
Venlafaxine’s safety and tolerability showed a favorable safety profile and was well-tolerated.
“[Venlafaxine] was an effective and safe treatment for many of the symptoms associated with fibromyalgia in subjects without major depressive disorder, particularly for women,” researchers wrote.